GPS World

Category: Applications

  • Col. Dave Madden Looks Back, and Forward into GPS Future

    Col. Dave Madden Looks Back, and Forward into GPS Future

    I had the honor of attending Colonel David Maddens’ retirement luncheon at the Space and Missile Systems Center (SMC) on Los Angeles Air Force Base (LAAFB) on June 16, and it was quite an event. Just prior to it, I asked Dave if he would like to conduct an exit interview after he took a short vacation with his family. He agreed it would be a good idea and a way to say some things he has wanted to say for awhile.

    During the retirement luncheon, various people and organizations presented Dave with mementos of his time at the GPS Wing; I stopped counting at approximately 50 different presentations. This is an indication of the high regard in which Dave is held by those with whom he works on a daily basis. The military shadowbox he was presented (see photo), which is a typical military farewell presentation, had the following inscription, which is certainly not typical, and sums up the way those who work with Dave feel about him as a commander and as a person.

    SHADOWBOX presented to Col. Madden on his retirement. The quote reads, in part,“The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly, who errs and comes up short again and again, because there is no effort without error or shortcoming, but who knows the great enthusiasms, the great devotions, who spends himself for a worthy cause; who, at the best, knows, in the end, the triumph of high achievement, and who, at the worst, if he fails, at least he fails while daring greatly, so that his place shall never be with those cold and timid souls who knew neither victory nor defeat.” Theodore Roosevelt, 1910
    SHADOWBOX presented to Col. Madden on his retirement. The quote reads, in part,“The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly, who errs and comes up short again and again, because there is no effort without error or shortcoming, but who knows the great enthusiasms, the great devotions, who spends himself for a worthy cause; who, at the best, knows, in the end, the triumph of high achievement, and who, at the worst, if he fails, at least he fails while daring greatly, so that his place shall never be with those cold and timid souls who knew neither victory nor defeat.”
    Theodore Roosevelt, 1910

    “It is not the critic who counts: not the man who points out how the strong man stumbles or where the doer of deeds could have done better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly, who errs and comes up short again and again, because there is no effort without error or shortcoming, but who knows the great enthusiasms, the great devotions, who spends himself for a worthy cause; who, at the best, knows, in the end, the triumph of high achievement, and who, at the worst, if he fails, at least he fails while daring greatly, so that his place shall never be with those cold and timid souls who knew neither victory nor defeat.”

    Theodore Roosevelt
    “Citizenship in a Republic,”
    Speech at the Sorbonne, Paris, April 23, 1910

    Dave was officially retired the next day by Colonel (USAF, retired) Bradford Parkinson. Dr. Parkinson was the first GPS Joint Program Office Director, in the early 1970s. He recently reviewed those early days and those responsible for the success of GPS with a two part series in the pages of GPS World.

    Interview

    Don Jewell (DJ): Dave, after almost four years first as the Vice Commander and then for the last three years the commander of the GPS Wing, of what are you most proud?

    Colonel David Madden (DM): Overall, the GPS Wing has made significant progress over the years moving critical space system developments and acquisitions forward. The GPS Wing continues to lead with a “back-to-basics” foundation of rigorous system engineering, incorporated strategies like parallel risk reduction and capability insertion efforts, incremental delivery of timely and valuable capabilities to warfighters and civil users, and best business practices with solid cost estimates and contract incentives. Our new GPS III space vehicle, Next Generation Control Segment, and our GPS Modernized User Equipment programs incorporate our latest thinking of these innovations, and pave the path as a model for future acquisitions: low risk and high confidene associated with program execution (cost, schedule and technical performance).

    The GPSW Team has had many specific accomplishments over the last four years. I would like to highlight just a few.

    Space Segment. In the space segment, we accomplished a major milestone in GPS history with the launch of the final GPS IIR-M satellite in Aug 2009. GPS IIR-21 (M) marked a critical milestone in the GPS modernization program that was initiated in early 2000. The GPS IIR/IIR-M satellites are the cornerstone of the GPS constellation, and I expect them to perform well into the future. We’ve completed the development, testing and launch operations of the first GPS IIF Space Vehicle. The GPS IIF is the “Dawn of a New Era” of GPS services, providing new and improved capabilities that will continue to support not only the warfighter but commercial and civil users around the globe. IIF vehicles two and three will be delivered by early 2011, and two of the remaining nine fixed-priced vehicles are already proceeding down the Boeing Pulse Line.

    Another noteworthy accomplishment was the award of the GPS III spacecraft contract. The GPS III will be developed in three increments with each increment to include more capabilities based on technical maturity. We successfully completed the GPS IIIA satellite Preliminary Design Review (PDR) in May 2009 and the GPS IIIA Critical Design Review (CDR) is scheduled for August 2010, two months ahead of schedule, which completes the detailed design and lays the foundation for fabrication. GPS IIIA is a back-to-basics spacecraft program with a strong focus on systems engineering, mission success, and acquisition excellence.

    Ground Segment. In the GPS ground control segment, great lengths were taken to ensure the successful replacement of the decades-old command and control (C2) system with the new Architecture Evolution Plan (AEP) software, to improve GPS operator interfaces while providing a test capability for the new signals on the modernized satellites and to improve launch, anomaly, and disposal (LADO) operations. This new software will also provide robust security improvements to include “over-the-air” distribution (OTAD) of encryption keys to properly equipped military users.

    I would also like to mention the successful award of the Next Generation Control Segment (OCX) back-to basics contract. The current acquisition strategy for fielding the OCX consists of four increments (commonly referred to as Blocks). The recently awarded OCX contract consists of Blocks one and two [while] Blocks three and four will be follow-on contracts that align with the future GPS IIIB and GPS IIIC spacecraft capabilities.

    Madden-1
    Colonel (USAF, retired) Bradford Parkinson congratulates Colonel Dave Madden on his fruitful career and retirement.

    User Segment. In the GPS user equipment segment, we are actively working the development of a new generation of military user equipment to take advantage of the modernized M-Code [military only] signals. Currently we are conducting technical demonstrations and risk reduction for our next generation Military GPS User Equipment (MGUE) and defining a creative acquisition strategy.

    USD-AT&L (the undersecretary of Defense for Acquisition, Technology and Logistics) signed an acquisition decision memorandum (ADM) on May 24, 2010, approving a material development decision for MGUE: the formal entry point for MGUE into the acquisition process. Currently, our three Military User Equipment (MUE) contractors are testing and delivering prototype cards this summer; government testing follows.

    The foundation of our MGUE acquisition strategy is an incremental approach that leverages technology developed under the MUE program to move into engineering and manufacturing development of the first MGUE receivers as soon as possible. The strategy will be submitted to the Pentagon this summer after SMC coordination and PEO Space approval.

    Our business strategy over the long term is to develop common GPS modules (CGMs) as the core engine for all DoD user equipment. We will develop CGMs incrementally as well, to support the form factors for the air, maritime, and ground domains. By early fall, we will have a final technical requirements document (TRD) for the MGUE form factors and CGM. We expect an RFP release in Feb 2011, and a Milestone A in May 2011. By early FY12, we should be on contract for Increment One of MGUE.

    System Sustainment. From a systems sustainment standpoint, our GPS Wing detachment located at Peterson AFB has exceeded all expectation associated with ground (softwa
    re and remote sites), user, and satellite systems sustainment. Even with all the system upgrades over the past year our sustainment team has kept the operational system performance well above the requirement: Read, no capability impact to civil or military users.

    In fact, performance (availability, accuracy, and integrity) has been significantly improved over the last four years. Finally, they are normalizing sustainment of the current user equipment (DAGR-Defense Advanced GPS Receiver, MAGR-2K-Miniaturized Airborne GPS Receiver Version 2, and ADAP-Advanced Digital Antenna Production program) by transitioning sustainment responsibility to Air Force Material Command, specifically the Warner Robins Air Logistics Center depot at Robins AFB, Georgia.

    Partnerships. The GPS Wing has established a close working relationship with Air Force Space Command Headquarters at Peterson AFB, Colorado for overall system operations, sustainment, and development responsibility; the 45th Space Wing (launch operations teams at Cape Canaveral Air Force Station in Florida), the 50th Space Wing (Overall System Operators at Schreiver AFB in Colorado), the Launch and Range Systems Wing (Los Angeles, California acquisition organization with responsibility for getting our GPS satellites successfully to orbit), the United Launch Alliance, the many government agencies (FAA, DOT, DOE, NSA, NGA, NASA, and so on), OSD organizations (PA&E, NII, AT&L, DOT&E), and our dedicated and professional prime contractors and major subcontractors to successfully sustain and enhance GPS mission capabilities — providing the highest overall daily system availability and the most robust GPS on-orbit constellation ever for war fighters and civil users worldwide. The constellation is healthier than it has ever been, and with the launch of the first IIF satellite and the on-track development of GPS IIIA, we are poised to maintain GPS as the gold standard for positioning, navigation, and timing well into the future.

    The People. Finally and most importantly, I am proud of the men and women that make up the GPS Wing. They have molded many players (Aerospace, MITRE, service reps, international officers, government and civil agencies, SE&I and SETA (support) contractors, and U.S. Air Force military and civilians) into a finely tuned machine that is always focused on the number one priority: mission success. At the same time they have made the Wing a fun place to work. The GPS Wing members have made significant contributions to the quality of life in the GPSW, on LAAFB (Los Angeles Air Force Base), and the local community. Whether it was the great Company Grade Officer Association activities, tasty Tuesdays, the BBQs by the base gym, the holiday parties, the POW/MIA (Prisoner of War/Missing in Action) Run, the yearly toy contributions to the Marine Corp Toys for Tots program, regular food drives to support the Redondo Beach community, the yearly car show, the GPS Partnership Council, GPS University, or the many visits to local schools (just to name a few activities), they are truly a class act of which I was honored to be a small part.

    DJ: Dave, how would you most like to be remembered?

    DM: As the “AGER” guy. The one who put the enterprise back together, which will lead to better synchronization among the segments and ultimately deliver future warfighting capability to the U.S. and Allied forces. Senior AF, DoD, and Congressional leadership now look at GPSW execution as a enterprise rather than a collection of individual ACAT 1D (Acquisition Category 1D) programs. This has allowed the modernization program to move forward, significantly reducing the numbers of reviews, documents, and decision complexity.

    DJ: Dave can you explain just where we are today in the ongoing GPS-IIF saga? Are we on track and on schedule to have IIF-1 activated sometime in late August? Will there be a second IIF launch this calendar year? Does Boeing finally have it all together?

    DM: Don, I’m actually glad you asked the question that way, because it gives me an opportunity to address it squarely. It is completely fair to call the GPS IIF program a saga because of how long it took us to get to our first launch. But it is also important to ensure the credit and blame gets spread properly. The program did suffer from the sins of acquisition reform in the 1990s — on the government side and the industry side —- as well as major requirements changes years after program initiation. In hindsight, I’d have to say that we collectively failed again in the mid 2000s when we were overly optimistic about the time and funding needed for the challenges we would face in recovering from TSPR (Total System Performance Responsibility). On the flip side, during my tenure here I’ve had great support from my senior leadership — and from their Boeing counterparts — for taking the time necessary to ensure we have a quality program. We kept our eye on mission assurance and fixed quite a few end-of-life risks. We might not have had that luxury if the constellation weren’t so robust over the past few years.

    In the end, the proof is in the on-orbit performance. So far, I’m proud to say that the checkout of SVN-62 has been proceeding very smoothly. My guys and Boeing have a great working relationship with the crews up at the 50th Space Wing, so the bird is in good hands. I expect we’ll find a few things we want to tweak before making the satellite available to users. Most space programs do that with the first satellite of a kind. In the end, the users will have a satellite that adds real benefit to the constellation performance.

    Right now the teams are still pushing hard to get SV-2 ready to launch. There are still a few hurdles to clear, and the leadership needs to evaluate whether or not the constellation really needs another GPS IIF just yet or can it wait until next summer. I would love to watch another one go up this year, but it just won’t be the same watching from the sidelines!

    DJ: I know it won’t be the same, Dave, but it should still be exciting. Now how about an update on the OCX program and how it is progressing?

    DM: The OCX program is off to a great start. We awarded the contract to Raytheon in February 2010 and kicked off the integrated baseline review (IBR) in March. We are currently working side-by-side with Raytheon to solidify the program management baseline so we can jointly manage the program in a back-to-basics manner. Phase B software development for controlling modernized features is underway and builds on Phase A products, which we demonstrated with a prototype in December 2008. I have tremendous confidence that the OCX program will deliver promised capabilities on time to support modernized GPS.

    DJ: Can you give us an update on where we are with the GPS IIIA program? Have you been successful in maintaining the no-changes mandate?

    DM: GPS IIIA has maintained a stringent, back-to-basics approach since program inception. This has included significant investment in early systems engineering, and strict requirements discipline. To date, no new requirements have been levied on the GPS IIIA. Any new requirements for consideration are being addressed in future blocks as planned. The program is currently on track, and is forecasting the completion of Critical Design Review 60 days ahead of the baseline schedule.

    DJ: We have satellites on orbit today that will reach their mean mission duration without broadcasting all resident signals or using all capabilities? Is there a plan to address this issue?

    DM: Although there is some concern that the IIR-M satellites may reach their end of life before the L2C capability has been deployed, or that the IIF satellites may reach their end of life before L5 has gone operational, the concern is not justified by our reliability predictions and our current program plans. Current plans are for OCX Block 1 to provide L2C support, which is projected in the August 2015 timeframe, whereas the IIR-M satellites are expected to live well into the 2020 timeframe. Likewise, OCX Block 2 will provide L5 support in the 2016 timeframe, and our IIF satellites are expected to live into the 2025 timeframe. Therefore the likelihood that IIR-M or IIF satellites will be decommissioned before L2C or L5 have become operational, respectively, is very low.

    Over the last couple of years, lots of discussion has gone into the integration issue, but I am not really sure what providing fully integrated GPS capability really means. What I do know is the user needs all three segments (satellite, ground command and control, and user equipment) to fully utilize new system capability. I also know that system integration comes in two forms. First and foremost from a technical design standpoint. This allows individual segments to be delivered independently but with high confidence the system will operate when all three elements arrive. This gives flexibility to the dynamics associated with budgets, policy decisions, requirements changes, unexpected technical hurdles, launch availability, and weapon platform availability for integration and testing (just to name a few variables). Rest assured the GPS enterprise is integrated at the technical level. However, it’s the second form of integration that gets all the attention: having all segments delivered in a reasonable proximity to each other. Not to make excuses, but as it relates to GPS, this is just hard to accomplish because it involves a span of control and accountability that is almost infinite. Many in the community recognize this reality, which has allowed the Air Force to set appropriate and realistic expectations so real capability can be delivered.

    That being said, there are prudent things that can and are being done to speed the deployment of capability and set appropriate expectations. The most significant has been to broadcast the M-Code, L2C, and soon L5 signals from space to allow civil and military user equipment manufacturers to begin development and testing of their next generation of receivers. This gives industry a jump while the U.S. Air Force continues to develop the C2 capability and the next-generation signal monitoring capability (required to ensure signal in space performance integrity). Also, building the modernization programs with a strong mission assurance foundation is a major step forward. We understand the lessons learned that established the baseline for the current Block II systems delivery; the Block III systems are built on a solid acquisition strategy of reduced risk and increase execution confidence.

    DJ: What do you see as one of the biggest GPS enterprise challenges, and what are some of your thoughts on the way ahead?

    DM: That’s easy, Don: ensuring global PNT services are not interrupted as the United States continues to modernize GPS. If we don’t continue to develop a more robust means of ensuring user equipment compatibility, even a small number of non-system-compatible receivers (military or civilian) can significantly delay the delivery of critical modernized capability for everyone. Let me explain and provide some thoughts.

    Since its initial design in the early 1970s, GPS has evolved in both capability and complexity. In the early days, systems engineering across the space, control, and user segments was relatively straightforward. The GPS Joint Program Office developed all military user equipment, and was able to rigorously ensure all specifications were verified prior to fielding. Over the past 20 years, however, GPS has become ubiquitous throughout the Department of Defense, with tailored satellite navigation solutions developed and acquired by dozens of program offices to support hundreds of unique requirements. Meanwhile, commercial GPS is one of the foundations of the Information Age, with GPS receivers produced in quantities approaching half a billion devices per year. The model of simply providing policies, standards, and interface control documents without providing a means to certify receiver compliance is becoming more challenging due to the continued growth in both military and civil applications for PNT, the competitive nature associated with user system applications and performance, and the increased complexity of GPS. Furthermore, it is especially difficult fielding upgrades to an established system like GPS while maintaining backwards compatibility with previously fielded equipment. These challenges are further exacerbated by difficulties associated with synchronizing the lengthy timelines associated with fielding ground-segment, satellite, and user equipment upgrades.

    Recent highly isolated incidents, involving civilian and military receiver and other manufacturers, have highlighted the significant impact a very small number of receivers experiencing compatibility issues can have on the entire enterprise of worldwide users. In addition, a number of cases associated with improper receiver integration into major weapon systems have delayed system fielding as well not allowed the weapon system to best optimize GPS to the overall weapon systems performance.

    Therefore, it is my opinion, to ensure worldwide PNT services are not interrupted as we continue to modernize the GPS, a more robust means of ensuring compatibility needs to be explored. (I would like to stop and make a note here: by “we” I mean all the DoD and civil agency stakeholders.) This means we need to not only continue to release “building codes” but we need to develop a capability to be more involved in the development, integration, and testing of new military and possibly civil user equipment.

    We have recently taken a number of big steps in this direction.

    First, we are currently significantly increasing the number of civil and military GPS receivers in our government testing labs. This will enable us to run tests against a wider variety of receivers, to gain higher confidence before we deploy system upgrades.

    Second, we recognize that we need to ensure that our signal specifications, for both military and civil users, are as clear as we can make them. User-community representatives are already encouraged to be full participants in appropriate interface-control working groups. We further recognize that there is no substitute for thorough testing, and hence fully appreciate the importance of deploying signal-in-space capabilities as early as possible, on predictable schedules, so user equipment can be field-tested prior to market release or operational deployment.

    Third, we are developing new upgrade fielding methodology whereby when we deploy system upgrades, we will take a more methodical approach and, whenever possible, field upgrades to smaller segments of receivers to prove compatibility without exposing all operational assets simultaneously. We will also apply a new software sustainment model to future military GPS user equipment, to ensure that inevitable system changes are systematically and rigorously executed with minimal impact on DOD programs.

    Finally, we are investigating the establishment of something similar to an underwriters laboratory service to help support military programs with integrating GPS into their weapon systems during development. The teams associated with such lab services would support program design reviews as well as help develop the validation criteria for overall system acceptance. In addition, we are also starting discussions with key GPS civil receiver developers on how we might be able to provide a similar service to commercial receiver developers (potential fee-for-service type model).

    Don, I highly recommend we continue to develop the four efforts I just mentioned but also dedicate significant time to critical thinking events to ensure we have minimized the risk of a widespread receiver issue, delays in delivering modernized capabilities, or sub-optimized weapon system performance. Manufacturers of equipment adversely affected by recent GPS upgrades have significantly stepped up their interactions with the GPS program office to resolve the compatibility issue and are playing a major role in providing an upgrade to their affected receivers to correct the issue. To date, no operational weapon systems have had to be grounded or civil capability degraded. I encourage the GPS community to treat recent events as a call to arms. GPS has become a critical national and international utility but it is much more complex than the electric or telephone services. How military or civil GPS receivers are designed, developed, and integrated into systems has a significant impact on the overall performance or lack of performance of the system. Don’t let recent events be a lesson not learned; let’s lead and solve the risk before it becomes an issue.

    DJ: These are all excellent ideas, Dave, and many of them we have discussed in the past as concepts. It sounds like many of them are now a work in progress, but since you won’t be around to shepherd them into fruition, just what sort of prudent advice would you give Colonel Bernie Gruber as he assumes command of the GPS Wing?

    DM: First and foremost, listen to your people — we have a great team! They are skilled professionals who really care about GPS. Second, keep the MGUE program focused and moving forward.

    DJ: I certainly hope at a minimum that Bernie listens to your advice on MGUE. Now, Dave, when will the GPS Wing transition back to a Joint Program office, and what affect will this have on the military personnel working GPS? Will this re-designation be detrimental to their careers and future plans for the JPO? Will it lessen the GPS Wing’s/JPO’s influence in the GPS community and with other services?

    DM: Don, we are scheduled to complete the transition and stand-up as the GPS Directorate on October 1, 2010. The Center is having one inactivation ceremony for all the Wings in SMC on September 8. The transition will be seamless and have a minimal effect on our military personnel. Our senior leadership is working on ensuring our materiel leader positions have group or squadron commander equivalency and will also be command-screened and boarded. There will not be very much difference within the Wing on a day-to-day basis. For the most part, the work, responsibility, and accountability will remain intact. The re-designation will have very little detriment upon the careers of the officers within the Wing. The officers’ records will show a transition and re-designation to explain the change, and that it is no cause of their own. As far as future plans for the organization, the strength of the leadership here in the Wing will still be in place and will be just as effective as it is now to lead each individual in our organization and to move forward and progress in GPS capabilities into the next era. Other services will still look to us to continue to forge advancements in GPS satellites so that our influence in the world’s GPS community will remain the standard: stronger than ever. Our organization will continue to acquire and sustain global navigation, positioning and timing services for our war fighters and civil users. We’ll still be the Green Monsters everyone knows and loves!

    DJ: What message would you like to leave with our readers as you move on from GPS to the milsatcom community?

    DM: GPS is in great hands. I look forward to the challenges ahead.

    DJ: Any final comments, Dave?

    DM: It has truly been a pleasure leading the GPS Team — my best job in 30 years of service. And you, Don, have also been a welcome friend.

    GPS improves the quality of life for everyone on the planet. It saves lives both on the battlefield and in our cities and towns across the globe. The U.S Air Force and Air Force Space Command have been the diligent stewards of GPS since program inception in the 1970s and continue its commitment to this critical component of our national infrastructure. The current GPS constellation has the most satellites and the greatest capability ever. We are committed to maintaining our current level of service, as well as striving to improve service and capability through ongoing modernization efforts. The Air Force will continue to pursue an achievable path maintaining GPS as the premier provider of positioning, navigation and timing for military and civilian users around the world.

    DJ: Dave, everyone at GPS World wishes you the best of luck in your future endeavors, and thank you for your honesty and candid responses to our inquiries through the years. You were the leader the GPS Wing needed for the last three plus years and you have left a legacy of which you can be justly proud. And in my opinion if the GPS Wing, Directorate or JPO thinks they have seen the last of Dave Madden, they should think again. Best of luck in milsatcom.

     

  • Get It Surveyed: ESRI Surveying and Engineering GIS Summit

    I attended (and presented at) the 2010 ESRI Surveying and Engineering GIS Summit (SEGS) last week, as well as the ESRI International User Conference (UC). I’m telling you, if you’ve never been to the SEGS and UC, just treat yourself one time. Make a mini-vacation out of it. San Diego is a beautiful place to visit. The weather is always moderate with low humidity and warm temperature. It was a little cooler this year than years past, but still absolutely beautiful with tons of sigh-seeing. My wife has accompanied me for the past few years and she always enjoys herself and finds something new every year.

    I believe that if you just go just one time, your vision of surveying, engineering, construction and GIS will change forever. I know it sounds like an advertisement from ESRI, but I think my pitch is even better than theirs :-). Seriously though, there are so many people presenting so many different ideas, and they are all related to the kind of geographic data you work with on a regular basis.

    But, like anything else, it’s not all good. There are some drawbacks, so I’ve come up with my Good, Bad, Ugly list with respect to the conference. I think its pretty objective.

    The Good

    • The single largest gathering (13,000+) of GIS, surveyors and engineers in the world (although one could argue that Europe’s INTERGEO might be larger).
    • A pre-conference (SEGS) that is designed specifically to cater to the land surveying and engineering folks.
    • Ideas and technology are presented that you will not find anywhere else.
    • The opportunity to network and collaborate with a large number of peers that you will not find anywhere else.
    • In 2011, the national ACSM (American Congress on Surveying and Mapping) conference will be combined with the SEGS.
    • San Diego is a beautiful city with beautiful weather and lots to do within walking distance of the convention center.

    The Bad

    • Since it’s a vendor-specific conference, ESRI competitors such as Autodesk, Intergraph, etc., are not invited. In fact, if you tick them off, they might not invite you back next year.
    • A lot of time away from work during prime field season (July).
    • You could be overloaded if you aren’t prepared for the barrage of information and technology.

    The Ugly

    • The whole experience isn’t cheap. The conference registration is expensive and San Diego is an expensive place to visit.
    • The San Diego airport is horrible, but at least it’s a very short ride to the convention center.

    The Surveying and Engineering GIS Summit (SEGS) is held the weekend prior to the massive User Conference (13,000+ people).

    At the end of the SEGS on Sunday (July 11), ESRI and ACSM (American Congress on Surveying and Mapping) announced that next year ACSM will be combining its national conference with SEGS in San Diego. The attendance is expected to be ~1,200.

    I’ve heard rumblings about this for quite awhile. Here are my thoughts.

    The ACSM national conference is dying and needed to do something drastic. This year, it co-located with the GITA (Geospatial Infrastructure Technology Association) national conference in Phoenix, Arizona, back in April. I attended that conference, too. Even though I was disappointed in the lack of coordination between the ACSM and GITA technical programs in Phoenix, the technical content was very good. Attendance, on the other hand, was horrible. It wasn’t sustainable from a business standpoint.

    Because the annual ACSM conference was on a quick road to nowhere; it had to make a move to team up with another conference. Who?

    The GITA conference dissed ACSM (or maybe the other way around) and is flying solo next year in Dallas, Texas. I think the attendance at the GITA conference will be a disaster. They already have a GITA Oil & Gas conference in Houston.

    Another partner choice would be ASPRS, but for some reason, ACSM and ASPRS can’t figure out how to put something together even though the conferences were at the same time this year. Someone’s ego probably got bruised.

    Partner with Autodesk? No way. Autodesk is a $2 billion behemoth. They don’t need or have the time to deal with ACSM.

    That leaves the ESRI SEGS. Attendance-wise, the SEGS has been flat, or even lost ground. It needed a boost. Bringing in ACSM was a smart move, essentially increasing its attendance from 300 to 1,200. For ACSM, it wasn’t the ideal choice, but it was the only choice. It couldn’t afford another solo event in some off-beat city. The bottom line is that conferences need a healthy number of exhibitors and commercial sponsors in order to be financially viable. For companies to be interested there needs to be a healthy number of attendees. It’s a vicious circle. If attendance wanes, then exhibitors and commercial sponsors start to pull out.

    Even though there is some pretty good upside for ACSM and ACSM membership in combining the conferences, I think the general ACSM membership will suffer. The primary reason is because it’s stuck in San Diego for the next three years. The U.S. Mid-Westerners and U.S. East Coaster’s will hesitate to make the trip due to the distance and expense of the conference, especially with the poor U.S. economy. I think what you’ll see are the state association conferences becoming stronger as they have been in the last few years. I wish, somehow, that some of the energy and excitement from the ESRI conferences could make their way to the state conferences.

    I may sound wishy-washy, but in the final analysis, I think this is a good move. For ACSM, it was the only move and for ESRI, a feather in their cap. It’s interesting to note that even though it’s a three-year agreement, either can opt out annually.

    On to the technical part of the SEGS conference

    I blogged about the SEGS while I was in San Diego. Click here to view my summary.

    A few of points I’d like to quickly emphasize:

    Crowd-sourced data. There’s a lot of buzz about this, and rightfully so. SEGS keynote speaker Nancy von Meyer commented on crowd-sourced data and the challenge of “authenticating” it. Crowd-sourced, or third-part,y data is coming in a big way. You can choose to ignore it, but the smart people will take the time to understand it and use it when appropriate.

    On a related point, a Community Basemap initiative was announced at the ESRI UC Plenary. The idea is that you contribute to the “community basemap” and, in return, you receive a better basemap than you started with. Granted, you have the same “data authentication” issues as crowd-sourced data, but if you understand it, there is value.

    Imagery (e.g. ,satellite images, aerial photography). From following t
    he satellite imagery vendors, I’ve known that imagery is progressing. Its quality (pixel resolution) and availability is improving. But, I’ll admit that I was taken back a bit when Lawrie Jordan, founder of ERDAS (he later sold to Leica) said this is the most exciting time in his 40-year career in imagery. He said that in less than five years, every square inch of the Earth will be constantly imaged by satellites. Now, ground truth accuracy is another story…

    On Sunday, I made the keynote presentation during lunch. The title of my presentation was Get It Surveyed (GIS). The title was said tongue-in-cheek of course. There were many directions I could have gone, but I decided on three topics.

    1. A GIS isn’t driven by spatial data accuracy.
    2. GNSS technology in the next 10 years is going to advance significantly faster than the past 10 years.
    3. The land surveyor’s role in the next 10 years is going to change significantly more than the past 10 years.

    You may take offense to some of the details in #3, and I’m sure some of you did. I assure you, my intent was not to offend, but rather stimulate thought and consideration. Some comments I received after my presentation.

    “You said what I’ve wanted to say, but can’t because my RPLS colleagues would kill me” (heard a version this from several people, two of whom are very prominent in the RPLS community).

    “You are spot-on” (heard some version of this several times).

    “Don’t forget about those who specialize in boundary surveys.”

    “Your timeline of 10 years is too conservative; it will be more like five.”

    A criticism I heard (not directly, but through the grapevine), was from someone who was particularly incensed by my presentation. I’m sure there were several people with this attitude. No doubt these criticisms are in reference to my thesis about land surveyors’ practices evolving and/or my comment that most RPLS’s aren’t qualified to manage a GIS. The criticism doesn’t surprise me. I’d be surprised (and probably disappointed) if it didn’t evoke any. Change doesn’t come easy and some will choose to give up rather than change.

    No matter if you were at the live presentation or not, I’d love you hear your comments on it. You can download it by clicking here.

    Lastly, during the Q&A after my presentation, I was caught flat-footed with a question about GIS licensure. I sort of stumbled and then stated that the technology is moving too rapidly and the bureaucracy of licensure couldn’t keep up. It didn’t take long for me to realize, and others to point out, that it wasn’t a very intelligent answer. Several people approached me afterwards and were able to express their opinions more eloquently and clearly. For what it’s worth, not one of them was in favor of GIS licensure. I will dedicate another article to this subject.

    In closing, following are some photos I took at the SEGS. I hope you enjoy them.

    Interesting slide from ESRI’s Brent Jones showing the attendance breakdown at the SEGS

    Countries represented at the SEGS

    Panel Discussion lead by ACSM’s Curt Sumner (Nancy von Meyer – VP Fairview Industries, David Cowen – NGA Committee Member, Wayne Harrison – President NSPS)

     

    Thought-provoking slide from Brent Jones

    Another thought-provoking slide from Brent

    Opportunities for surveyors in GIS according to Brent Jones

     

    Thanks for reading, and see you next time.

    Follow me on Twitter at http://twitter.com/GPSGIS_Eric

  • Kick It in and Push!

    By Alan Cameron

    The Elephant Charge (“Dust, Sweat, and Gears”), an annual off-road motorsport charity event, brings together competitors, their families, and supporters for a wilderness weekend of GPS-driven fun and frenzy in the Zambian bush. I’m for fun, but I always wince when I see folks tearing up habitat in the name of saving it.

    Elephant Charge 2010 seeks to raise funds and awareness for local conservation in Zambia, specifically for two hides, or wildlife observation posts, in Lusaka National Park along with funding for the South Luangwa, Lower Zambezi and Kafue National Parks private-sector conservation efforts. Organizers hope to attract more than 300 campers over the weekend of October 23–25 and as many day observers and participants, en route to a fundraising goal of $35,000.

    Focus of the weekend is an event for car and motorbike teams that requires stamina, sweat, driving, and navigation skills through the Zambian bush. Maps showing the location and GPS coordinates of nine checkpoints are issued to teams on the evening before the race. To win, a team must complete the nine-checkpoint course in the shortest distance among competitors. Each team finds it own route between the checkpoints, in any order, through valleys, over ridges, and up (or down) escarpments. The goal of short distance explicitly encourages teams to go off-road in their vehicles. Bush roads are cut to each checkpoint and marked on the issued maps, however they never give the shortest distance.

    The blog piece you are reading is armchair bushwhacking at best, and it’s hard for me to preach at a distance to Zambians on how to use, exploit, preserve, or tear up their own turf. Of course it’s heartening to see GPS enlisted in conservation and education efforts. I just wish they weren’t harming habitat — by cutting bush roads and further encouraging racers to rip off through the vegetation — in order to help preserve it.

    Visit www.elephantcharge.org for more information.

    Alternatively, for a terrific vicarious experience of the Africa savannahs and bush without leaving home, read either Don’t Let’s Go to the Dogs Tonight by Alexandra Fuller, set in Rhodesia, Zambia, and Malawi, or Sand Rivers by Peter Mathiessen, set in Tanzania. “The crack of the dry grass, the intense heat, the startling beauty of the birds, the fleeting glimpse of wary wildlife . . .”

  • Elbow Room on the Shoulder: DGPS-Based Lane-Keeping Enlists Laser Scanners for Safety and Efficiency

    Elbow Room on the Shoulder: DGPS-Based Lane-Keeping Enlists Laser Scanners for Safety and Efficiency

    A virtual reference station network covering a metropolitan area supplies position corrections to commuter buses equipped with a driver-assist system to enable safe operation, even under harsh weather conditions, along high-volume roadways.

    By Craig Shankwitz

    Bus-only shoulders on major traffic arteries enable a bus to travel on typically unused road right-of-way, bypassing congestion during peak rush hours. As the shoulder is typically only centimeters wider than the bus itself, lane-keeping becomes a key factor, and is accomplished in a pilot Minnesota project using dual-frequency, carrier-phase differential GPS (DGPS) as its primary positioning technology. DGPS provides position estimates accurate to 5–8 centimeters at a rate of 10 Hz, and is used to determine vehicle position and heading. An on-board map database is used to determine the position, orientation, and trajectory of the vehicle relative to the roadway.

    Use of the shoulder as a busway offers several construction and operational advantages:

    • Ease of Implementation. The shoulder exists; there is no need to acquire and develop additional right of way.
    • Low Costs. The cost to strengthen and modify an existing road shoulder is significantly less than constructing a new busway.
    • Routing. Because bus-only shoulders follow existing routes, no changes to bus routes, bus stops, or transit stations are needed to support bus-only shoulder operations.
    • Customer Satisfaction. Transit customers who travel on buses that use a bus-only shoulder perceive a travel-time saving two to three times greater than actually realized. Keeping the bus moving at all times offers a significant psychological advantage.
    • Increased Ridership. A 1997 study of bus-only shoulders in the Twin Cities analyzed more than nine bus-only shoulder routes for two years and found a 9.2-percent increase in ridership along these routes. At the same time, total ridership had decreased by 6.5 percent.

    However, the use of bus-only shoulders imposes additional stress and strain on a driver. The narrow bus-only shoulder leaves a driver very little margin of error. Operating within this small margin is difficult even during the best traffic and weather conditions, and degrades to nearly impossible during heavy traffic and poor weather conditions, which are frequent during Minnesota’s notoriously hard winters.

    During difficult weather and traffic conditions, the use of the bus-only shoulder offers its greatest transit advantage. If a driver is unable to utilize the bus-only shoulder, this advantage is lost. A properly designed and executed driver-assist system (DAS) enables a driver to use the shoulder under all conditions, thereby increasing schedule adherence and, as a result, rider satisfaction.

    Under the U.S. Department of Transportation’s Urban Partnership Agreement, the University of Minnesota’s Intelligent Vehicles Lab (IV Lab) and HumanFIRST program, the Minnesota Valley Transit Authority (MVTA), and Schmitty and Sons Transportation will soon deploy DAS on 10 Gillig low-floor transit buses. These buses will provide express service between Apple Valley and downtown Minneapolis, a 22-mile, one-way trip.

    Driver-Assist History

    The IV Lab has developed and deployed DGPS-based DAS since 1995. The first deployment on public roads occurred in 2001, as part of the DOT’s Intelligent Vehicle Initiative Generation Zero Field Operational Test. The DGPS-based lane-keeping assistance was integrated with forward-looking radar for collision avoidance, enabling safe vehicle operation in zero-visibility conditions.

    Two separate deployments took place in Alaska. The first occurred in 2003 with a snowplow and a snowblower which clear the Thompson Pass on the Richardson Highway. These vehicles are still in use. Because of this success, the State of Alaska installed the DAS in two more vehicles at Deadhorse Airport.

    During the summer of 2010, the two original Thompson Pass systems will be upgraded with new computational hardware, and three new systems will be installed on three new highway maintenance vehicles. The value of the driver-assist system has been proven, and those who use it have grown to rely on its all-weather capabilities. It has functioned reliably for seven years in extremely harsh conditions.

    ÅDAS-EQUIPPEDSNOWPLOWclearingThompsonPass,Alaska.
    DAS-EQUIPPED SNOWPLOW clearing Thompson Pass, Alaska.

    Driver-Assist for Transit

    The DAS provides two primary capabilities for transit applications: lane-keeping and collision awareness. The system provides assistance only; a driver is always responsible for control of the vehicle. Figure 1 shows the components comprising the DAS.

    Figure 1. Complete driver assist system component schematic, showing both infrastructure-based and vehicle-based components.
    Figure 1. Complete driver assist system component schematic, showing both infrastructure-based and vehicle-based components.

    DGPS-Based Lane-Keeping. The primary positioning sensor used aboard the buses is a dual-frequency, carrier-phase GNSS receiver, providing centimeter-accurate position measurements at 10 Hz. With the exception of the DGPS augmentation system described later, all other DAS system processes are synchronized with the arrival of DGPS position updates.

    Realtime CMR+ DGPS corrections are provided over the 3G cellular network from the IV Lab VRS network. The IV Lab VRS network is based on six receivers located around the perimeter of the Twin Cities Metro area. These six receivers are connected via landlines to a server system located in the IV Lab at the University of Minnesota, running GPSnet and RTKnet applications. To ensure GPS correction reliability, an integrity manager software issues alerts for both short-term and long-term aberrations in the data provided by the six base stations. This ensures accurate corrections are sent to the buses using the narrow shoulders.

    The onboard receiver also plays a crucial role in accurately estimating vehicle body heading. In rural applications where GPS augmentation is unnecessary, GPS velocity heading estimates provided directly from a GPS receiver serve as a sufficiently accurate body-heading estimate. However, in GPS-denied environments where an augmentation system is needed to provide accurate position and heading estimates when GPS is lost, velocity heading from an onboard receiver is an insufficiently accurate estimate of vehicle heading. To support such navigation, the IV Lab developed a technique, described later, by which body heading can be estimated with errors less than 0.1 degree.

    IV Lab mapping rig installed in a pickup truck: three dual-frequency, carrier-phase DGPS receivers; two laser scanners, one measuring retroreflectivity, the other road crown and rutting; and forward and sideview cameras, to help analyze anomalous data.
    IV Lab mapping rig installed in a pickup truck: three dual-frequency, carrier-phase DGPS receivers; two laser scanners, one measuring retroreflectivity, the other road crown and rutting; and forward and sideview cameras, to help analyze anomalous data.

    Map Databases

    Lane-keeping uses DGPS with an onboard map database describing the location and type of lane boundaries and other relevant roadway elements to an accuracy of approximately 10 centimeters. These map databases can be constructed in one of three ways:

    • from sufficiently accurate photogrammetric data,
    • by driving centerlines and using known road-construction standards to d
      etermine the location of lane boundaries and other relevant elements relative to the lane centerline, or
    • by using a combination of laser scanners, DGPS receivers, and cameras to determine the global location of the reflective markings that bound lanes and shoulders.

    Lane-keeping information is continuously provided to the driver; lane-departure alerts and warnings use a comparison of vehicle speed and heading to the map database to determine when alerts and warnings should be issued.

    The alerts and warnings are provided via a multi-modal human-machine interface (HMI), illustrated in Figure 2, through three modes:

    • graphically, through a head-up display (HUD) that gives a virtual view out the windshield when environmental conditions limit visibility;
    • haptically, through a torque-actuated steering wheel giving a restorative torque on the steering wheel in the event of lane drift; and
    • tactically, through a seat equipped with actuators that vibrate on the side of the seat to which the lane is being departed.
    Figure 2. Multi-modal driver interfaces. Left: Graphical, haptic, and tactile feedback modes provided to the driver. Upper right: View through the head-up display. Graphical lane departure alert indicated by left shoulder boundary colored red, collision awareness alert (white rectangles), and collision awareness warning (red rectangle). Lower right: Forward, left, and right side collision awareness information presented on the display on the left “A” pillar.
    Figure 2. Multi-modal driver interfaces. Left: Graphical, haptic, and tactile feedback modes provided to the driver. Upper right: View through the head-up display. Graphical lane departure alert indicated by left shoulder boundary colored red, collision awareness alert (white rectangles), and collision awareness warning (red rectangle). Lower right: Forward, left, and right side collision awareness information presented on the display on the left “A” pillar.

    Lane-departure warnings come in stages. As the vehicle-trajectory estimator determines that the likelihood of a lane departure is sufficiently high, a lane-departure warning is issued to the driver through the HUD: a change in lane boundary color from white or yellow to red. Should the driver contact the lane boundary, a seat-based warning is activated; the side of the seat corresponding to the direction of lane departure vibrates, warning the driver. If the driver fails to respond to these two stimuli and continues past the lane boundary, the steering motor torque is applied. This multi-stage approach captures the drivers’ attention, but if they respond in a timely fashion, their annoyance is limited.

    The torque applied by the steering servo motor is limited, and cannot deliver sufficient control action to autonomously steer the vehicle. This is by design; the driver is responsible for operating the bus. The level of torque applied to the steering wheel is analogous to an automotive front-end misalignment; it is sufficient to capture the drivers’ attention, but not to steer a bus off the road.

    Forward-Collision Awareness. Sensing for forward-collision assistance is provided by a front bumper-mounted multi-plane scanning LIDAR sensor. Forward-collision alert and warning information is provided in two stages to the driver through the HUD. As now configured, if the obstacle detected is in the present shoulder of travel, the obstacle is represented as a red, open rectangle, with red indicating a warning status. If an object is located in an adjacent lane, the obstacle is represented as a white, open rectangle, with white indicating an alert status.

    Obstacle-detection processing is enhanced by the presence of the onboard map database used for lane-keeping. Obstacle target information provided by the LIDAR sensor includes range, range rate, and azimuth angle to the target. The bus position and heading is provided by either DGPS or the DGPS augmentation system. Through a coordinate transformation, LIDAR information in the vehicle coordinate frame is transferred to the global coordinate frame. This allows the LIDAR target to be placed on the map database; if the target is in the vehicle lane of travel, it can be considered a threat, but if the LIDAR target is not in the same lane as the bus, then at that time the target is not a threat to the driver.

    Side-Collision Awareness. Side collision awareness is enhanced by multi-plane LIDAR scanners mounted on on the front bumpers on both the left and right sides of the bus, and connected to a pneumatic actuator.

    Side-collision awareness information is provided to the driver via an LCD panel mounted on the left front A-Pillar (see Figure 2). This display is touch-sensitive, and can be used by the driver to log in (only certified, trained drivers can operate the system) to select feedback modalities (choose any or all of the available feedback modes) and to check system status.

    SIDE-MOUNTED LASER SCANNER used for both side-collision awareness and DGPS augmentation. When extended (left), the LIDAR scans 100 degrees of the horizontal plane. One boundary of the scanned plane points behind and runs alongside the bus; the other boundary points forward of the bus by approximately 10 degrees. When retracted (right), the LIDAR points in the direction of the ground, and can be used for curb-following when DGPS is unavailable.
    SIDE-MOUNTED LASER SCANNER used for both side-collision awareness and DGPS augmentation. When extended, the LIDAR scans 100 degrees of the horizontal plane. One boundary of the scanned plane points behind and runs alongside the bus; the other boundary points forward of the bus by approximately 10 degrees.
    Figure_6B
    SIDE-MOUNTED LASER SCANNER used for both side-collision awareness and DGPS augmentation. When retracted (right), the LIDAR points in the direction of the ground, and can be used for curb-following when DGPS is unavailable.

    Suburban and Urban

    Although the rural implementation of the DAS operates in extremely harsh weather conditions, these implementations are technically less problematic than suburban and urban implementations. In rural applications such as the snowplows, DAS-equipped vehicles typically operate with a single occupant in a small geographic area, travel on relatively low traffic-volume roads, and enjoy a clear view of the sky. Suburban and urban applications carry passengers, operate across a wider geographic area, travel on high-volume roads, and suffer from periods where view of GPS satellites is either partially or completely blocked.

    These operational differences require substantial changes to the DAS subsystems for urban/suburban use.

    DGPS Base Stations. In rural areas, DAS-equipped vehicles typically operate over a relatively small geographic area; a single GPS base station will provide adequate coverage as the maximum baseline between rover and the base station remains less than 25 miles. Suburban applications cover a much wider area, and a network of DGPS correction stations is needed to keep baselines low.

    For the UPA project, the IV Lab operates a six-station virtual reference station (VRS) network. This network covers the greater Twin Cities Metropolitan area, and supplies compact measurement record (CMR) corrections to each DAS-equipped bus. Satellite observables are sent from each base station receiver to both the VRS server at the IV Lab and to a VRS server at the Minnesota Department of Transportation.

    Broadcast of DGPS Corrections. In rural areas, the DAS system has served to keep roads passable in inclement weather conditions. This has been viewed as a safety application, and as such either UHF or VHF channels in the public safety bands have been used to broadcast DGPS corrections. In urban areas, no single UHF or VHF frequency is available to cover an entire metropolitan area. Therefore 3G cellular data communications are used to provide DGPS corrections to DAS-equipped vehicles.

    Use of 3G cellular data communications brings the transit customer an added benefit: free Wi-Fi. The provision of DGPS corrections, using the CMR+ correction format, requires approximately 10 Kbit/second. This bandwidth is assigned high priority by the onboard router. The remaining 700 Kbit/s of 3G bandwidth is made available, at a lower priority, to bus passengers. On an express route service, passengers can e-mail and surf the web on their daily commute, making productive use of
    time that might otherwise be lost.

    The VRS server provides a unique correction to each DAS-equipped bus. Communication between the bus and the VRS server is initiated by the bus when it sends its coarse (uncorrected) position to the server. The server replies with a correction optimized for that coarse location. Corrections are sent at one-second intervals. Every two minutes, the bus sends its current position, and the VRS server responds with corrections optimized for that new location. With this scheme, the baseline between the VRS and the roving bus is never more than two miles. The two-mile limit maintains position accuracy without consuming excessive wireless or computational bandwidth.

    DGPS Redundancy. In rural applications, the view of the sky is generally unobstructed, and FCC licenses provide adequate effective radiated power from the DGPS base stations. This assurance of access to both satellite and corrections signals generally suffices to support uninterrupted vehicle positioning. Both base-station and onboard GPS hardware have proven to be robust and reliable. With these local operating conditions, public agencies have found no need to augment DGPS for rural applications.

    Suburban and urban applications, however, require an augmentation system to support DAS operation when DGPS is unavailable due to outages caused by overpasses, overhead road signs, tree canopies, and so on. Passenger safety and the need to provide reliable schedule adherence require that positioning be provided even when DGPS is unavailable, by a vehicle-based DGPS augmentation system.

    Vehicle-Based Augmentation

    The vehicle-based augmentation system (VBAS) uses direct measurements of ground velocity, a measure of vehicle yaw rate, and an accurate estimate of the vehicle position and heading at the time DGPS is lost to estimate vehicle position and heading for the duration of signal loss.

    A commercial off-the-shelf sensor designed for measuring vehicle and/or tire slip measures vehicle 2D velocity. Yaw rate can be measured either with an inertial rotational rate sensor or a second 2D velocity sensor. Yaw rate measured using a pair of these 2D sensors eliminates the rate bias and rate bias drift associated with inertial sensors. Figure 3 shows both configurations.

    FIGURE 3 Two approaches to VBAS to mitigate DGPS outages. The diagram on left shows implementation with two 2D velocity sensors to determine vehicle yaw rate. Computationally, this is attractive as senor drift need not be considered. The diagram on the right shows an implementation with one yaw rate sensor, and one 2D velocity sensor. This is the configuration operating for the UPA; it requires yaw rate sensor drift compensation to provide accurate measures of vehicle yaw rate.
    FIGURE 3 Two approaches to VBAS to mitigate DGPS outages. The diagram on left shows implementation with two 2D velocity sensors to determine vehicle yaw rate. Computationally, this is attractive as senor drift need not be considered. The diagram on the right shows an implementation with one yaw rate sensor, and one 2D velocity sensor. This is the configuration operating for the UPA; it requires yaw rate sensor drift compensation to provide accurate measures of vehicle yaw rate.

    An accurate measure of vehicle heading at the time GPS positioning is lost is critical to the augmentation process. A performance goal of 20 centimeters tolerable error at the end of a 15-second outage for a vehicle traveling at 25 miles per hour (11.2 meters/second) requires a heading estimation error of no more than 0.07 degrees (that assumes the only source of error is attributable to the heading).

    GPS outages (time from loss of position to reacquisition) attributed to passing under overpasses range from 7 seconds (single bridge) to 9 seconds (double bridge). The IV Lab augmentation system reliably provides sufficiently accurate position and heading estimates to carry through these outages. At the present level of performance, should an outage last more than 15 seconds, the accuracy of the augmentation system cannot be guaranteed. In this event, the driver is alerted, and the DAS is deactivated until a DGPS position fix is reacquired. Fortunately, since new receiver firmware was installed, no instances of an outage exceeding 15 seconds have occurred during two months of test, evaluation, and driver training.

    Figure 4 illustrates the accuracy of the VBAS system. At the time the fix solution is reacquired on the exit ramp, the lateral error between the fix solution and the position estimated by the VBAS is approximately 10 centimeters. This accuracy is sufficient to allow a driver to travel on the entrance ramp even during zero-visibility conditions.

    Figure 4. Example of VBAS as a bus operates on the Cedar Avenue/Old Shakopee Road overpass. Bus trajectory is northbound on Cedar, exiting westbound Old Shakopee Road, then entering southbound Cedar Avenue from Old Shakopee Road. Upper left shows northbound trajectory and loss of satellite lock. Upper right shows reacquisition of DGPS, float, and fix states of the DGPS receiver. Lower right shows accuracy of VBAS system compared to DGPS when DGPS reacquires fix. Lateral error of VBAS at at the time the fix is reacquired is approximately 10 centimeters. Lower left shows satellite view of the interchange.
    Figure 4. Example of VBAS as a bus operates on the Cedar Avenue/Old Shakopee Road overpass. Bus trajectory is northbound on Cedar, exiting westbound Old Shakopee Road, then entering southbound Cedar Avenue from Old Shakopee Road. Upper left shows northbound trajectory and loss of satellite lock. Upper right shows reacquisition of DGPS, float, and fix states of the DGPS receiver. Lower right shows accuracy of VBAS system compared to DGPS when DGPS reacquires fix. Lateral error of VBAS at at the time the fix is reacquired is approximately 10 centimeters. Lower left shows satellite view of the interchange.

    Driver Training

    Bus-only shoulder operation has proven itself safe and, in fact, safer than normal transit operations, according to recent data. The goal of driver training is to prepare drivers to use the DAS system to enable them to safely use the bus-only shoulders in conditions under which they normally would not.

    A rigorous training protocol developed in cooperation with the University of Minnesota HumanFIRST program, Schmitty and Sons Transportation driving instructors, and MVTA involves both simulator-based and on-road training.

    Simulator-Based Training

    Beefore using driver assist systems, bus drivers are continually taught that the driver controls the bus and is responsible for both the passengers and vehicle. Drivers take this responsibility seriously, and as such, develop skills and techniques that guarantee safe passage under all conditions, even when running on narrow, bus-only shoulders.

    To best prepare drivers for using the DAS under difficult conditions, a high-fidelity driving simulator was commissioned. A DAS was installed in the simulator, and an interface to the simulator was created. In this context, a driver has the ability to train in normal and abnormal (low to zero visibility) conditions before beginning on-road DAS training and use.

    In the simulator, the driver learns that the system only provides assistance; responsibility for the safety of the bus and passengers still resides with the driver. Experience with Alaskan snowplow operations, where formal training is limited to a few on-road test drives, has shown that a driver may take a few winter seasons to fully accept the system. This delayed acceptance is in part attributable to the fact that for six months per year a driver has no opportunity to train with the system. Acceptance gained over one winter season is lost during the summer.

    The simulator installed at an MVTA bus garage uses a seat-based motion platform to achieve realistic vehicle dynamics. The DAS installed in the simulator allows a driver to train in all weather and traffic conditions on a geospecific roadway before transitioning to a DAS-equipped bus. Geospecificity is achieved through the creation of virtual worlds based on roadway data collected by the mapping vehicle shown earlier.

    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.
    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.
    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.
    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.
    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.
    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.
    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.
    Bus-driving simulator at the MVTA bus garage in Burnsville, Minnesota.

    On-Road Training

    After a driver both demonstrates an
    d acknowledges comfort and competence with the DAS in the simulator, training transitions to the actual route on which the buses will operate. Each of the 10 buses is equipped with a six-camera data-acquisition system. The six cameras capture not only the driver’s actions (hands, face, feet), but also views of the road (front, left, and right sides.)

    Drivers travel with an instructor. The onboard data acquisition system can be used to reconstruct particular scenarios as a means to offer advice as to how the driver and system can better interact in difficult driving and traffic conditions.

    On-road training benefits system developers as well. Training offers a driver an opportunity to test the system in real-time on an actual road. The perspective a driver brings is generally different than that of the developer, and the insights the end user provides typically produce a better system. As an example, driver experience with the system during the initial training period produced the staged approach to lane-departure alerts previously described.

    Conclusion

    The IV Lab, MVTA, and Schmitty and Sons Transportation will soon release 10 DAS-equipped buses into revenue service to support narrow bus-only shoulder service between downtown Minneapolis and Apple Valley, Minnesota. Although the IV Lab has deployed a number of DAS-equipped vehicles, this UPA deployment represents the first time that the system has been used to transport passengers. This deployment should prove that although DGPS systems are susceptible to periodic outages, a properly designed and executed augmentation system will provide a sufficiently robust system that will be accepted by both drivers and passengers. It will also demonstrate to other transit agencies that even narrow rights of way offer significant transit advantages at low cost, and that potential operational difficulties can be overcome through the use of DAS technologies.

    Manufacturers

    The buses carry Trimble R7 receivers and Ibeo Lux multi-plane scanning LIDAR sensors. The IV Lab VRS network is based on six Trimble NetR5 receivers. The server runs Trimble’s GPSnet and RTKnet applications, with the Trimble Integrity Manager.

    Craig Shankwitz is the director of the Intelligent Vehicles Laboratory at the University of Minnesota.

  • Sensor Fusion in Forestry

    Sensor Fusion in Forestry

    By Jürgen Rossmann, Petra Krahwinkler, and Markus Emde

    Modern machines such as wood harvesters can automatically cut trees and remove branches, but an expert is still needed to plan a thinning and to mark the trees to be felled. The process can be accelerated if the forest ranger can virtually mark trees to be cut, using geographic coordinates instead of colored crosses sprayed on the stems. This requires the robotic wood harvester to be able to locate itself accurately to enable automatic navigation to the next tree for cutting.

    Absorption of the GPS signal in the forest canopy leads to poor results, however, with errors up to 50 meters and more. Furthermore, the canopy may cause interruptions and signal loss for several seconds. The performance can be even worse on a moving vehicle, where the signal may even get lost until the vehicle reaches an open area or stops.

    Other approaches use differential GPS (DGPS) sensors as their main source of position information. However, our experiments using a high-precision DGPS sensor showed that its accuracy is not even close to sufficient for navigating to a single tree. As the DGPS suffers from the same canopy-related disturbances and shielding, it cannot benefit from its theoretical advantages. In pratice, the DGPS system did not update its position at all when signal reception became too weak.

    A different approach was needed. We found it in the framework of the Virtual Forest, more precisely in the semantic modelling of forests, where techniques are being developed to delineate single trees from remote sensing data, such as airborne laser scanner data. Along with the trees and their geo-coordinates, the height and the diameter at breast-height are determined. This data can be used to generate a tree map, which can be used for navigation. The map has a mean error between 0.5 and 1.5 meters, which is still below the mean tree distance of about 2.5 meters.

    Visual GPS. The idea of Visual GPS is to bring current developments in the field of robotics into the forest and combine them with information on forest inventory so that the result outperforms other navigation approaches. A matching algorithm is run based on a tree map, generated from remote sensing data, and the tree group, which was detected by one or more laser scanners.

    We then implemented a particle filter algorithm, as it enables considering different kinds of distributions. Particles are also called random state samples, and each particle is a hypothesis as to what the true world state might be.

    In the initialization, particles are distributed uniformly. An importance weight wt is calculated for each particle, incorporating the measurements as described below. A sampling step rejects particles with a low importance weight and replaces them with new particles, which are distributed according to the previous map. This process is repeated until the particle distribution concentrates at one point, and the particle with the highest weight is returned as the result (see Figure 1).

    Figure 1. Particle concentration after resampling; wood harvester at center.
    Figure 1. Particle concentration after resampling; wood harvester at center.

    A single tree as a landmark cannot be associated with its corresponding tree in the map. However, patterns of tree positions can be matched. We chose a square area to guarantee even particle distribution and short calculation time. Each particle represents a hypothesis for the position of the vehicle and is tested for its probability to represent that position.

    To make the approach more robust against faulty tree maps, we implemented a rotation variant approach, determining vehicle heading along with its position. This enhanced the probability measure used in the propagation step. Instead of embracing only the distances of the trees to the reference point, their relative position is used, considering the heading wt of the current particle:

    equation-forest

    This approach directly calculates vehicle heading, but the sensitivity towards rotation, which results from the new probability measure, leads to a higher number of particles that must be used during the initialization step.

    Global Search. Experiments on a test area with about 22,700 trees proved that the algorithm worked reliably for tree groups containing 20 or more trees, and for position errors of the magnitude of the mean tree distance. Similar tree groups could not be found within the forest. However, the calculation time was too long to be used for navigation.

    Local Search. To overcome the high calculation time, we reduced the number of particles. The initial position is estimated with an ordinary GPS sensor. Although the GPS measurement is faulty in the forest, it can limit the search to a restricted area. Machines most often start at the edge of a forest stand, at a forest road, or a canopy opening. At these spots the canopy usually is transparent, and GPS sensors work with higher precision. Therefore, they provide a good initialization for the algorithm.

    Robotic wood harvester.
    Robotic wood harvester.

    In the following steps, the previous position can be used instead of the output of the GPS sensor for determining the search area. The previous position provides a better initial pose estimation than the GPS sensor and therefore gives the opportunity to further decrease the search area.

    To reduce the number of trees for which the distance has to be calculated, trees with a distance from the initial pose estimation smaller than the sum of the estimation of the maximal position error and the maximal distance of the trees in the scanned tree group from the reference position are extracted from the tree map.

    Another way to reduce the search area is to estimate vehicle orientation. This is difficult for machines such as wood harvester, which moves slowly and stops frequently when cutting trees. Therefore, small lateral position differences result in large orientation deviances, as the difference vector does not directly point into the direction of the movement any more. Another approach is to use sensor fusion and mount a compass onto the vehicle. During particle initialization, the angle can be restricted to the domain of uncertainty around the compass orientation. However, mounting a compass onto a wood harvester proved to be a serious problem, as the harvester’s massive metal body disturbs the compass measurement.

    Figure 2 shows the workflow of the complete system.

    Figure 2. Navigation system components.
    Figure 2. Navigation system components.

    Results

    The simple criterion presented here proved to be reliable in the vast majority of cases. Problems can occur when the tree group contains trees that are not part of the tree map (false positive). This can happen due to missing trees in the tree map or faulty tree cognition in the local laser scanner measurement. In the first case, the understory might not have been detected in the airborne laser scanner data. In the second case, other objects like the harvester’s aggregate might have been mistaken for a tree.

    The case of trees not detected in the local laser scanner measurements but contained in the tree map (false negative) does not create problems in the pose estimation step. The algorithm searches for a corresponding tree for each unit in the tree group. For a false positive, no corresponding tree can be found, whereas a false negative is simply not considered. However, if the size of the tree group is too small, the estimation errors grow. The minimum number of trees depends on the search area radius. A size of 20 trees proved to generate reliable pose estimations even during the global search. Dropping below 15 trees, the number of faulty position increases rapidly as more similar patterns can be found.

    Single faulty positions can be filtered with respect to the movement constraints of a harvester. The velocity is very low, and the orientation cannot jump. In the experiments, cycle times of about 0.5 seconds were reached on a standard PC. As forest machines do not demand very short calculation time, the algorithm proved to run fast enough to allow identification of single felled trees onboard real machines. One application of the algorithm was to support a navigation assistant to the next tree, similar to navigation systems in cars.

    To evaluate system accuracy on a real wood harvester, a surveyor’s office was instructed to measure the vehicle’s position at seven distinct locations. At each position, the sensor input data was written to file for several seconds. This data was evaluated, and for each location more than 45 pose estimations were calculated. The mean value of the position error amounted to approximately 0.55 meters.

    Future Work

    Reliability can be enhanced by using a detailed digital ground model and the cabin tilt in order to detect the area where the laser beams hit the ground, and therefore avoid the detection of false positives. Similarly, the position of the aggregate, which can be measured by integrating sensors in the hydraulic cylinders of the crane, can be cut from the laser scanner measurements and ignored during tree detection, further reducing the amount of false positives in the tree group. With the integration of an outlier rejection step for false positives in the detected tree groups that ignores trees for which no corresponding candidate tree can be found, a more accurate importance factor can be calculated.

    Another task is the integration of the algorithm with a Kalman filter to allow real-time performance of the algorithm. Therefore, the Kalman filter is initialized with the pose estimation of the particle filter algorithm, which is also used for continuous checks of the current position estimate, thereby combining two algorithms with different advantages. The Kalman filter allows real-time execution and therefore speeds up the overall navigation algorithm. The particle filter algorithm can periodically check the position estimated by the Kalman filter and correct it. Furthermore, it provides a strong method to cope with two main problems in mobile robotics: the data association problem and the kidnapped robot problem.

    Simultaneously, a mapping and map-correction algorithm could be integrated into the system so that understory trees, which cannot be detected using remote sensing data, and deciduous trees, which are more difficult to delineate in airborne laser scanner data, can be added to the tree map.

    Jürgen Rossmann is head of the Institute of Man-Machine Interaction at the RWTH Aachen University, where Petra Krahwinkler and Markus Emde are research scientists.

  • U.S. Army Testing Rugged, Autonomous Robot Vehicle

     

    The U.S. Army’s Autonomous Platform Demonstrator, or APD, is a 9.6-ton, six-wheeled, hybrid-electric robotic vehicle currently undergoing developmental and mobility testing at Aberdeen Proving Ground, Maryland. According to an Army statement, the demonstrator vehicle represents the state of the art in unmanned ground vehicle mobility technology.

    With its advanced hybrid-electric drive train, the 15-foot-long vehicle, being developed by the U.S. Army Tank Automotive Research, Development and Engineering Center (TARDEC), can achieve speeds of more than 50 mph.

    When equipped with its autonomous navigation system, the APD is configured with GPS waypoint technology, an inertial measurement unit and computer algorithms which enable it to move autonomously at speeds up to 50 mph while avoiding obstacles in its path.

    “The vehicle has obstacle detection and avoidance technology,” said Jim Overholt, senior research scientist in robotics at TARDEC.

    The mobility testing is aimed at advancing and developing the robot’s ability to maneuver at higher speeds while maintaining extreme terrain-ability at lower speeds.

    “We’ve run it through courses, slope testing and brake testing,” said Chris Ostrowski, associate director for Vehicle Electronics and Architectures at TARDEC.

    The APD is currently testing high-speed maneuverability, such as lane changing. “This is a challenging controls problem with a skid steer vehicle. We want the robot to be stable when performing maneuvers like this, but we also want it to retain the other mobility characteristics that it possesses at lower speeds,” said Ostrowski.

    Other mobility characteristics include the ability to climb a one-meter step, navigate a 60-percent slope, and pivot turn in place.

    Being a series hybrid-electric vehicle, the APD is propelled by six in-hub electric motors and has a diesel generator which charges its lithium ion batteries.

    “The state-of-the-art hybrid-electric drive train is just one of the mobility technologies we are demonstrating with this platform,” said Andrew Kerbrat, APD project manager, TARDEC.

    Other technologies being demonstrated include advanced suspension systems, thermal and power management systems, robotic safety systems, and lightweight hull technologies.

    “We’ve made a lot of progress with this platform in a short time period. From concept to wheels on the ground was just a shade over two years, and in the eight months since then, we’ve driven almost 3,000 kilometers and have demonstrated 95 percent of the metrics that we were trying to show with this platform,” said Kerbrat.

    APD is the mobility platform being used by the Robotic Vehicle Control Architecture, or RVCA Army Technology Objective, also out of TARDEC. Working with PEO-Integration, RVCA has integrated a suite of system control, display and sensing hardware and software onto APD that allow it to be controled real-time by a Soldier, or operate in an autonomous mode.

    “It uses a variety of sensors and a Ladar — a laser/radar scanning radar that can detect moving objects at distances,” said Overholt. Additionally, RVCA provides Reconnaissance Surveillance and Target Acquisition capabilities.

    “It has a four-meter mast with a sensor ball on top so it goes up pretty high and can see out quite a ways,” said Chris Ostrowski.

    “When you combine the autonomy and control capabilities provided by RVCA with the extreme mobility characteristics of APD, it allows the Soldier operator to quickly deploy a mission payload precisely where he wants it, and over some very tough terrain,” said Kerbrat.

    “The bottom line is that we are providing the soldier with a significant capability that will assist him in the performance of his mission, while keeping him safer in the process.”

  • Follow up: What’s Going to Happen When GPS Accuracy is Cheap?

    I received some interesting e-mails and saw some web comments regarding my newsletter column a couple of weeks ago titled “What’s Going to Happen When High-Accuracy GPS is Cheap?” The comments ranged from “I don’t believe it’s going to happen” to “We’d better adapt to the changes in technology.”

    One comment in particular had me thinking about the title of the original article. Looking back, perhaps I should have used the word “precision” instead of “accuracy” in the title of the article. Accuracy is a tricky subject and a subjective term. What’s accurate to one person may not be to another. Also, you may be precisely correct, but not very accurate at all.

    The point of the commentor was that high-precision GPS equipment in the hands of the general public will create many problems. There’s no doubt that will happen. Is there going to be a new type of service that surveyors can market to in order to clean up the problems that are created? Probably, and quite possibly only a small percentage of today’s surveyors will be qualified to do this type of work. One’s ability to understand and work with spatial data will be critical in helping organizations solve geospatial data problems. Thus, the importance of data management knowledge and skills I’ve mentioned before.

    Geodesy is going to play a big role in the future, regardless if you don’t believe in GPS precision becoming as cheap as I believe. One can’t argue that precision and accuracy are improving, and with that will come geodetic problems with legacy data that need to be solved. Just imagine an electric utility company with its entire distribution system in a GIS (or CAD) that’s been ammended many times over a 30-year period. Imagine the disparate data sources and wildly varying data accuracy in such a system.

    Let’s look at two of the other comments I received. Please note I’ve paraphrased, and sometimes combined, comments for the sake of brevity:

     

    “They thought EDMs, total stations and online GIS were going to change surveying too, but they really didn’t.”

    EDM’s and total stations are complicated and complex instruments (not to say that GPS receivers aren’t). About 10 years ago when my eldest son was nine, I taught him how to map using RTK. Granted, he was a classic “button-pusher,” having no idea what the technology was doing, but he knew which buttons to push to map a soccer field. I taught him to do this in less than 15 minutes. There’s no way I could have taught him to map a soccer field using an EDM or a total station in that amount of time, even if I had a full day. The first difference between GPS and other mapping instruments: it’s very easy to learn and use.

    This subject reminds me of a photo sent to me from Indonesia many years ago. A guy I knew was training a massive number of Indonesian (200+) foresters on how to use handheld GPS/GIS data collectors. They had little or no previous experience with GPS. He had an auditorium set up with a large projection screen. In one of his Powerpoint slides, he had a photo of a chimpanzee sitting next to a GPS receiver. His point was, of course, that anyone can be taught to map using a GPS receiver. At that time, equipment and software wasn’t as easy to use as it is today. For starters, one had to post-process GPS data to improve accuracy, but even then the point he was making was clear. The ending exercise for the class was to locate three $100 bills stashed separately somewhere in Jakarta using only GPS coordinates provided. I thought that was an ingenius way of keeping the class attentive.

    Anyway, back to the topic.

    There are several reasons one can’t view future high-precision GPS L1/L5 receivers the same as EDMs, total stations, or any other automated measurement tool. GPS is simply different and will have a much greater impact on the way surveyors and their clients work.

    1. GPS receivers are orders of magnitude easier to use and more productive than any other surveying measurement tool in history.
    2. GPS is a mainstream consumer electronic technology that is spurring a lot of innovation.
    3. With L5, GPS technology will be very precise (horizontal and vertical) and very inexpensive.

    For these reasons, I think you can view GPS L1/L5 receivers as game-changing and industry-altering technology. The combination of ease-of-use and low-cost will put high-precision GPS in the hands of everyone from the garbage collector to the policeman mapping accident scenes. That wasn’t the case with EDMs, total stations, or any other measurement technology.

     

    “Consumer-grade GPS receivers and survey-grade GPS receivers are not the same quality and never will be.”

    This isn’t the case according to several GNSS receiver designers I’ve spoken to. There’s no reason a “consumer-grade” L1/L5 GPS receiver can’t achieve cm-level precision (horizontally and vertically) with a good quality antenna. Of course, it will need a source of correction, but in the 5-10 year window, RTK corrections will be more available and less expensive than they are today. The RTK corrections will likely be free so the only expense will be the wireless data plan.

    There will be dozens, maybe hundreds of GPS chipsets designed for L1/L5. Many will be open systems where companies will be able to load their own firmware into the receiver to add specific features (e.g., more robust ambiguity resolution for surveying). The baseline L1/L5 GPS receiver may be only a few hundred dollars, but a customized version for specific applications will have a premium of a few hundred, or maybe $1,000+. For example, a GPS L1/L5 receiver that also includes Galileo signal and is customized for machine control with specific features might be $1,500. Commercial users will pay that premium. They already justify paying tens of thousands of dollars for the same performance today. The difference is that a low price point will attract a much larger audience.

    There’s no doubt that there will be boutique, niche GPS L1/L5 receivers that will be able to garner a premium price, but surely the days of many thousands of dollars for high-precision GPS receiver are heading to an end.

     

    This is not the end of land surveying. I didn’t claim it before and I don’t claim it now. That idea is ludicrous. But, you have to ask yourself how much time you spend on projects that will be affected by this technology.

    If 75% of your work is boundary surveys, perhaps you won’t be concerned as much as the company that generates 75% of its revenue from construction work or topographic surveys.

    If 75% of your work is mortgage surveys, you’ve got more to worry about than high-precision GPS.  :-)

    My point is that change is inevitable and that people who have the attitude that this is just another Chicken Little call (the sky is falling!) will be in for a rude awakening when the rubber hits the road. We can have a friendly debate about when this will happen, but there’s absolutely no doubt that it will.

     

    Free Webinar on June 24

    On June 24, Geospatial Solutions will be conducting a free 60-minute webinar, moderated by me, on “GIS Mapping for Forestry, Agriculture, and Other Natural Resource Professionals.” I will discuss GIS mapping software tools/concepts/techniques as well as GIS mapping hardware such as GPS receivers, digital cameras, and laser rangefinders. Although focused on natural resources, it will be relevant for all pe
    ople interested in GIS mapping, which could be utility companies, municipalities, transportation organizations, etc. Sign up now by clicking here and submit questions in advance.

     

    Thanks, and see you next week.

    Follow me on Twitter at https://twitter.com/GPSGIS_Eric

     

  • INRIX Announces INRIX Traffic! and INRIX Traffic! Pro Availability for iPad

    INRIX announced the upcoming release of a new iPad version of INRIX Traffic!, its popular app for commuters.

    Using the MDK (mobile developer kit), INRIX completed development of an iPad optimized version of its popular INRIX Traffic! and INRIX Traffic! Pro app in less than 2 weeks. Coming later this month to the iPad App Store, INRIX Traffic! is a free app that provides real-time traffic, traffic forecast, speed trap, accident and incident information for all major cities and roads across the U.S. and Canada. Winner of a 2010 MacWorld Best of Show Award, INRIX Traffic! Pro is available as an in-app upgrade to the free app that provides motorists with the added benefit of always knowing the fastest route, best time to leave, travel time and ETA for any destination.

    “Our mobile apps and tools have helped companies like Ford and providers of 8 of the top 10 most popular GPS smartphone navigation apps get to market fast with new traffic-powered navigation services,” said INRIX President and CEO Bryan Mistele. “Bill’s experience helps us transform our unique consumer insights into new features that extend beyond INRIX Traffic! to apps that empower our partners and customers to deliver consumer experiences that make navigation more useful every day.”

  • What’s Going to Happen When High-Accuracy GPS is Cheap?

    Last week, as you may have heard given the multiple launch delays, the United Launch Alliance (a Lockheed and Boeing joint venture), under contract with the U.S. Air Force, successfully rocketed a new GPS satellite into orbit.

    The GPS satellite launched into orbit last week wasn’t just any other GPS satellite. It was the first of a new generation of GPS satellites that are going to change the way surveying, engineering and construction data is collected and processed in the future. Its new features are going to profoundly transform surveying, engineering and construction. I’m not exaggerating.

    Before you stop reading because you think you’ve read this already in my other newsletter, Geospatial Solutions Weekly released earlier this week, hang in there because although some of it is the same, I’ve added some surveying-specific comments.

    First of all, it’s important to understand that this is going to happen. It’s not a matter of if, but rather when. What I mean is the price of high-accuracy GPS is going to be very inexpensive, both horizontal and vertical, and it’s going to dramatically affect your business.

    Here’s why.

    The new L5 signal will eventually (when it’s being broadcast from enough satellites – more on that later) significantly transform GPS receivers in two ways:

    1. It will result in high-accuracy GPS receivers being much cheaper and smaller.
    2. It will make collecting high-accuracy GPS data much more convenient for the average person.

    Let’s examine in more detail.

    Why will high-accuracy GPS receivers be cheaper and smaller?

    Today’s GPS dual-frequency receivers (L1/L2) can achieve a high level of accuracy (1 cm) in a short period of time, as little as a few seconds. But, they are expensive. An entry-level GPS dual-frequency receiver is a few thousand U.S. dollars. The primary reason is because there is a limited number of companies that design GPS dual-frequency receivers for surveying, maybe a dozen or so. Why is there a limited number of manufacturers? The answer is because the original L2 was not an open signal. In the 1980s, some very smart engineers figured out how to utilize L2 (designed for military use only) in commercial receivers. When they developed those techniques, the companies were smart enough to patent them. There are so many patents in place that it makes it very difficult for a new designer to enter the traditional GPS dual-frequency market, whether it’s surveying, machine control, GIS, or whatever.

    Unlike the original L2, L5 is an open signal. Its specification is published for anyone to use. No license fee. No receiver tax. Nothing.

    Without any patent blocks, any company in the world is free to develop a GPS dual-frequency (L1/L5) receiver that would be just as accurate, and arguably more accurate, than today’s L1/L2 GPS dual-frequency receivers.

    Looking back on the history of electronics, within and outside the GPS industry, we know that increased competition usually results in lower prices to the consumer and improved product quality.

    Take, for example, GPS L1 receiver chips used in personal navigation devices and mobile phones. Those chips are available today for less than $3 each. Fifteen years ago, much less powerful GPS L1 receivers were $200 each and 10 times larger.

    Mark my words: you will see a similar trend with high accuracy GPS dual-frequency receivers. GPS dual-frequency receivers will be sold at prices you can’t imagine today, allowing surveyors, engineers, contractors, GIS folks, biologists, ecologists, etc. (and an educated general public) to collect high-accuracy data (horizontal and vertical) very inexpensively.

    The only thing holding this trend back is the availability of L5. It needs to be broadcast by  about 24 GPS satellites. That’s going to happen somewhere between 2018 and 2020. Of course, GPS designers will be working on their receivers long before that.

    Why will collecting high-accuracy GPS data be much more convenient for the average person?

    First of all, the cost of high-accuracy GPS dual-frequency receivers will plummet significantly due to the open L5 signal. This will spur a fantastic amount of innovation and competition among a large number of receiver designers, especially in the consumer electronics market. Surveyors, engineer, contractors, GIS folks, etc. will benefit greatly from the consumer electronics industry because the high volumes in the consumer market will further spur innovation and cost reduction.

    Oddly enough, at that time, the most expensive part of a high-accuracy GPS receiver may be the antenna. The consumer electronics market won’t accept the type of high-accuracy GPS antenna we need (too big/bulky), so the limited number of antennas means you’ll pay a higher price, maybe a $100, maybe $200.

    If you have a minute, you might want to browse this article by Dr. Frank van Diggelen. Essentially, he says that consumer GPS receivers in your mobile phone, PND, etc. can be as accurate as a GPS receivers built for high-accuracy surveying. The reason they aren’t, he says, is due largely to the inferior antenna being used in mobile phones, PNDs, etc. Now, I’m not saying I buy everything he’s writing, but he’s a lot smarter than I am with regards to GPS, and I do have enough experience to know that antennas can make a big difference in receiver performance.

    What you’ll see, eventually, is GPS dual-frequency (L1/L5) receiver technology in consumer electronics, which means high-accuracy positioning at consumer prices. Take it a step further and one can make the statement that high-accuracy positioning will be in the hands of the consumer. A knowledgeable consumer will be able to take a  low-cost, high-accuracy GPS dual-frequency receiver and collect (or have others collect) an amazing amount of valuable data (think high-accuracy vertical) that would otherwise be too expensive to collect using today’s technology.

    That is where we are headed, guaranteed.

    Wildcards

    Other GNSS

    The time-frame estimation I made above (2018-2020) for a full (24-satellite) constellation of GPS satellites broadcasting L5 is based solely on the activities of the U.S. government. Keep in mind that the U.S. government can’t exceed the 2020 deadline because December 31, 2020, is when the U.S. Air Force says it will stop supporting legacy GPS L1/L2 dual-frequency receivers. So, the end of 2020 is the worst-case scenario.

    Of course, the U.S. isn’t the only country working on GNSS. Europe’s Galileo system also utilizes L1 and L5. It’s possible that in the 2014 timeframe, the U.S. could have a dozen GPS satellites broadcasting L1/L5 and Galileo could have a dozen Galileo satellites broadcasting L1/L5. Because the U.S. and Europe have been working so closely together to ensure GPS and Galileo work together seamlessly, having 12 Galileo satellites broadcasting L1/L5 is the same as GPS broadcasting L1/L5.

    China is also working on a GNSS called Compass/BeiDou. Although China is very tight-lipped with its intentions, it’s possible China could launch some satellites in orbit that may contribute to an L1/L5 solution, but China is a serious wildcard.

    L2C

    Some of you may be wondering why I haven’t included GPS L2C in the discussion. L2C is an open GPS signal much like L5. There are currently seven GPS satellites broadcasting L2
    C. Not including Galileo, there will be 24 GPS satellites broadcasting L2C before there are 24 GPS satellites broadcasting L5. In fact, some designers may decide to develop L1/L2C receivers. However, Galileo isn’t supporting L2 so while there will probably be triple-frequency receivers (L1/L2C/L5), my guess is that the standard will be L1/L5, because the third frequency isn’t going to buy you much.

    Conclusion

    No other conclusion can be drawn but that in the future, as soon as 2014 and as late as 2020, high-accuracy GPS receivers (cm-level in both horizontal and vertical) will be in the hands of anyone with a few hundred dollars to spend. This will be consumers as well as surveyors, engineers, contractors, GIS folks, and many other folks who see value in spatial data. They will have easy access to a fantastic new tool that will allow them to collect high-accuracy, horizontal and vertical data, at a very low cost and very conveniently. I keep referring to vertical accuracy because accurate vertical data is much more expensive to acquire with the technology that exists today, GPS and otherwise. Not so in the future. When one really thinks about the value of accurate low-cost vertical data, the numbers of applications are mind-boggling and will certainly send all disciplines that use spatial data in a new direction.

    Perhaps no discipline will be more affected by this technology advancement than surveying. If you’re retiring in five years, you can probably get away with not thinking about this. But, if you’ve got more than that left in your career, you really need to consider what direction you want to go.

    The bad news is that you have to change. Change is stressful, especially at mid-career, but you don’t have a choice if you want to enjoy a career in surveying. Technology is transforming surveying. You know it because you’ve been feeling the squeeze. You’ve seen that engineers and contractors have acquired technology tools to bring some activities in-house. Machine control is an obvious one. In just a few years, you likely won’t be doing the same sorts of tasks you’re doing today. There will be much more emphasis on data management and data analysis than on data collection (less field time, more office time). Of course, there will still be a need for people in the field, but that’s not where the professional wage is going to be earned. Those in the field will only have jobs, not careers. The well-paying careers will be in the office (either home office or business office or mobile office).

    The good news is that there’s more opportunity than ever before. I can’t count the number of times I’ve had people from different organizations (public and private) ask me if I knew someone who could help solve their geospatial problem. Sometimes, it’s a problem combining data sets. Sometimes, it’s a problem interpreting the data they have as well as finding or collecting new data. Guess what? They aren’t looking in the telephone book (yellow pages) to find someone to help solve their problem. In fact, in some cases they don’t even care if you live in the same country as they do. True, you may have to travel to their office, but they don’t care as long as you solve their problems. I realize this may be a strange concept to many of you, but the Internet has made the world a lot smaller than it used to be. Your clients don’t have to be located within 200 miles of your office. You can have clients in different counties, states, provinces, and even countries! When you start letting go of the idea that your clients need to be geographically close to you, suddenly your business prospects start to look bright. When you limit your ten-person company to clients located within 100 miles in rural Alabama in this economy, you’re going to starve. When you release that limit and start thinking and acting regionally, statewide, nationwide, or worldwide, all of the sudden there’s a lot more opportunity to keep your employees working.

    One important note

    In order to take advantage of the opportunities I mentioned above, you have to expand your knowledgebase. There’s no choice. It’s either that or you’re bagging groceries at Walmart. Technology is changing and its forcing changes in your business, so you must adapt to those changes. Recently, I wrote about a technical session at the ACSM/GITA conference I attended called the Surveying Body of Knowledge (SBoK). Although I may have some differences with some of the SBoK committee member’s intentions, the concept is right. SBoK does a good job of defining the different disciplines in which surveyors can diversify. Briefly, the five areas are:

    1. Positioning (field data collection)
    2. Imaging (photogrammetry/remote sensing/3D scanners/LiDAR/)
    3. GIS (mapping/cartography)
    4. Law (boundary/real property/business law)
    5. Land development (construction/planning/development)

    The idea is that if one discipline is weak, such as positioning, in the current economy, then you could shift your business in another direction where you are qualified, such as GIS or imaging. You certainly don’t need to be qualified in all five disciplines, but having three or four in your pocket gives you a lot of flexibility when the economy is as weak as it is now.

     

    Thanks, and see you next time.

    Free Webinar on June 24th

    On June 24 (was originally scheduled for June 22), I will be conducting a free 60-minute webinar on “GIS Mapping for Forestry, Agriculture, and Other Natural Resource Professionals.” I will discuss GIS mapping software tools/concepts/techniques as well as GIS mapping hardware such as GPS receivers, digital cameras, and laser rangefinders. Although focused on natural resources, it will be relevant for all people interested in GIS mapping, which could be utility companies, municipalities, transportation organizations, etc.  Sign up now by clicking here and submit questions in advance.

    Follow me on Twitter at

    https://twitter.com/GPSGIS_Eric

  • GPS, GLONASS, and SBAS Webinar Follow-up

    Normally, my column following a webinar is dedicated to Q&A follow-up from the webinar. However, immediately following the April 22 webinar, I traveled to Phoenix, Arizona, to attend the ACSM/GITA conference, which I wrote about earlier this month.

    This column is dedicated to answering questions I didn’t address during the webinar. Also, I always find the results from the polls I conduct during the webinar very interesting.

    Poll #1: Have you or your work crews had to stop or alter your work pattern due to the lack of GPS satellites?

    Total votes: 128, Yes: 73%, No: 27%

    Gakstatter comment: This is consistent with other polls I’ve conducted regarding GPS satellite availability. The new GPS 24+3 configuration will help mitigate this problem. Read more about the new GPS 24+3 configuration in a three-part series I wrote earlier this year.

     

    Poll #2: How often do you upgrade your GPS equipment?

    Total votes: 113

    Gakstatter comment: There’s no clear pattern here except to say that 46% of the users wait until at least 3 years before they consider upgrading their GPS equipment. That makes sense to me.

     

    Poll #3: Does any of your GNSS equipment utilize GLONASS?

    Total votes: 115, Yes: 39%, No: 61%

    Gakstatter comment: When considering the result of this poll, keep in mind that there are very few “mapping-grade” receivers that are designed to utilize GLONASS. For example, there are very few, if any, sub-meter receivers that utilize GLONASS, primarily due to the lack of correction sources. SBAS doesn’t support GLONASS, DGPS (radiobeacon) doesn’t support GLONASS, and most CORS do not support GLONASS. Only recently did OmniSTAR begin supporting GLONASS. I think this trend will continue, although I doubt that SBAS or DGPS (radiobeacon) will support GLONASS in the foreseeable future.

    Poll #4: Does any of your GNSS equipment utilize SBAS (WAAS/EGNOS/MSAS) as a primary source of corrections?

    Total votes: 111, Yes: 60.5%, No: 39.5%

    Gakstatter comment: This poll result doesn’t surprise me. Given that SBAS corrections are widely available, free of charge, reasonably accurate, and require no action by the user, it makes a lot of sense they are being used.

    Following are some of the questions that were posed by the audience during the webinar:

    Question #1: I am not sure, but when you say you’re “pushing” something out to us, it sounds like your trying to “push” something on us. Just a comment.

    Gakstatter: I’m sorry about the webinar-speak. When I say “pushing the next slide,” that means I’m changing slides. I may change the way I say this. Thanks for your comment.

    Question #2: Can you correct GLONASS signals with WAAS or other real-time technologies?

    Gakstatter: WAAS (or any SBAS) doesn’t support GLONASS. Neither does DGPS (radiobeacon). This doesn’t mean that GLONASS measurement can’t be used, but you’ll be using uncorrected measurements to augment SBAS-corrected measurements. A case where it may be useful is when you’re mapping in an environment where there are a lot of trees. You might only have four GPS satellites visible that are being corrected via SBAS. In that scenario, there might be value in utilizing measurements from GLONASS satellites just to improve the PDOP, even though the GLONASS measurements are uncorrected.

    Question #3: Do you feel manufacturers will begin to release lower-end mapping-grade GPS receivers with L2C and L5 functionality in the future?

    Gakstatter: Yes, I do, but it will be a few years before there are enough satellites broadcasting an L5 signal. I think what you’ll end up seeing are inexpensive L1/L5 receivers (Galileo doesn’t support L2). They will not only be able to provide mapping-grade sub-meter, decimeter) but also RTK accuracies (cm-level). Since L2C and L5 are open civil signals, you won’t see the patent blocks that restrict competition for L1/L2 receivers like you do today.

    I’m not saying L2C will not be supported at all. I think there will be L1/L2C/L5 receivers, but I think you’ll see L1/L5 on lower-end receivers.

    Question #4: There is apparently some degradation of accuracy when using GPS and GLONASS for RTK. Have there been any rigorous studies quantifying this that you are aware of?

    Gakstatter: I’m not sure I’d say I believe there is degradation in accuracy, but I wouldn’t count on GLONASS to improve accuracy. The value of GLONASS is improving productivity. Since it adds several satellite signals to the solution, it effectively eliminates GPS “brown-out” periods so RTK can be used 24/7. There was a rigorous study released by The Survey Association in the UK. The report focused on network RTK. They tested both GPS and GPS+GLONASS. You can download a copy of the report here.

    Question #5: Does using GLONASS-capable receivers shorten the observation time required for fast-static points?

    Gakstatter: My first thought is yes since generally more observables equates to shorter occupation time, but I would check with the manufacturer and follow their recommendations. Honestly, I’ve only used fast-static with GPS-only receivers so I don’t have any personal experience with your scenario.

    Question #6: When is GLONASS-K launch scheduled? When can we receiver a valid CDMA signal?

    Gakstatter: The first GLONASS-K satellite is scheduled for launch later this year. I haven’t seen a launch schedule beyond that. A representative from the Russian Space Agency is scheduled to present at the Institute of Navigation (ION) GNSS conference in September, so I’ll probably learn more at that point. However, it’s a lengthy process. It’s not just a matter of launching satellites. There are many other variables and unknowns such as the control segment and user equipment compatibility. I think it’s safe to say that we are a few years away from having a minimal GLONASS satellite constellation broadcasting CDMA.

    Question #7: The visibility plots show one extra satellite in the “after” plots. Was that intentional? I would have expected there to be an improved number of satellites visible when one more was added to the plotted constellation.

    Gakstatter: Good catch. In the “after” scenario, I set SVN-49 healthy, which it is currently not. The reason I did this was because SVN-49 is in an important slot in the 24+3 configuration. The status of SVN-49 is still undecided, but if they decide to not set it healthy they will move another satellite to take its place in the 24+3 configuration. If I would have kept it unhealthy in the “after” scenario, it would have only s
    hown a 24+2 configuration. Clear as mud?

    Question #8: Is 24+3 the solution to the blackout problem from now to 2014 stated by the GAO Report from last year?

    Gakstatter: The definition of the 24+3 configuration had been around before the GAO Report. Personally, I don’t think the GAO Report had anything to do with 24+3. The 24+3 configuration just helps optimize the current satellites in orbit, whereas the GAO Report addresses the attrition of GPS satellites outpacing the addition of GPS satellites.

    Question #9: Cellphone question: Is the move to 24+3 likely to degrade indoor GPS coverage – fewer peak sats => lower probability of seeing 4+ sats indoors?

    Gakstatter: Interesting question. My first thought is probably so, although I think it would be a temporary problem. Assuming Galileo keeps pushing forward, that would be a big help for cellphone users, both indoors and outdoors.

    Question #10: GPS Satellites are getting beyond the design life…is the USA behind schedule in satellite updates?

    Gakstatter: GPS satellites have been unbelievably reliable. PRN-24, the oldest operational satellite, has been in operation since August 30, 1991. Since they have been so reliable, there hasn’t been as much pressure to launch GPS satellites. Prior to the 24+3 initiative, the minimum guaranteed constellation was 24 satellites. It costs $50-60 million to build each GPS satellite and another $150-200 million to launch it. With the GPS constellation hovering around 30 satellites these past few years, and government budgets tightening, I think it’s clear that the pressure to save money has resulted in a more relaxed launch schedule.

    The delay in the Block IIF satellite (the first one being launched this week) was not a result of the above, but rather technical and program management mis-steps. The GAO Report was particularly critical of the IIF development.

    Question #11: Do you see any future for ground-based free systems such as those broadcasting corrections in LF/MF radio, like the Coast Guard broadcasts?

    Gakstatter:     There is an interesting debate between DGPS (what you mention) and SBAS. The DGPS infrastructure has been in place and working reliably for mariners for better than a decade. Funding for DGPS seems solid for marine navigation, but less stable for inland-based applications (like the U.S. NDGPS system). I think the future of DGPS for mariners is solid for the next 10 years. Once there is a full constellation of satellites broadcasting GPS L5, the value of DGPS will be questioned.

    Question #12: Will WAAS, EGNOS, etc. be needed after L1/L5 receivers can measure the iono effects themselves?

    Gakstatter: I think it comes down to integrity. If the L1/L5 combo can deliver integrity that safety-of-life applications require (such as aviation), then one has to question the value of SBAS. My gut feeling is that the L1/L5 combo can’t and that some sort of augmentation will be needed to attain the integrity level required.

    Question #13: What are your thoughts concerning Compass? Do you feel this will eventually be applicable for public use as part of a functioning GNSS?

    Gakstatter: Compass is the GNSS wildcard. Since the Chinese aren’t particularly forthcoming with their plans, it’s hard to say. But I’m not sure that matters. With a full constellation of GPS, GLONASS (CDMA), and Galileo satellites in the future, that’s around an average of 25+ satellites in view at any one time during the day. If China doesn’t play well with others in a timely fashion, the user community won’t care what Compass brings to the table.

    Question #14: If my current GPS receiver is not ready for L2C and L5, do I have to buy a new GPS or I can upgrade software/firmware later so that I can still use it?

    Gakstatter: You’ll have to trade-in. Some might be upgradable to L2C, but L5 is a different story. It’s a completely different frequency. That affects the receiver as well as the antenna.

    I wasn’t able to address all of the questions here, so look for more in the next newsletter. Particularly I’ll cover some discussion about reference frames, SBAS and L5.

    Look for announcements in the next day or so about the Block IIF GPS satellite launch. It’s scheduled for Friday, May 21. It’s a new era with the first GPS satellite to broadcast an operational L5 signal.

    Thanks, and see you next time.

    Follow me on Twitter at http://twitter.com/GPSGIS_Eric

  • INRIX’s Crowd-Sourced Traffic Network Surpasses 2 Million Vehicles

    INRIX announced its Smart Driver Network has grown to more than 2 million GPS-enabled vehicles giving drivers a reliable, real-time view of traffic conditions on more than 260,000 miles of highways, city streets and secondary roads nationwide.

    “Our Smart Driver Network is the largest real-time traffic network in the world. It redefines what it means to deliver truly real-time traffic information,” said INRIX President and CEO Bryan Mistele.

    According to the announcement, more than 40 percent of all State DOTs in the United States rely on INRIX’s real-time traffic information for their daily operations, traveler information services and/or congestion performance measures. New projects in 2010 in 5 states – Texas, Massachusetts, Maryland, Minnesota and Ohio – are using INRIX traffic data and travel times for their planning efforts, statewide 511 systems or dynamic message signs.

    “In just two years, INRIX has grown from providing traffic data for one state agency to powering the daily operations, planning or traveler information services in 21 states and the District of Columbia,” said INRIX Vice President of Public Sector Rick Schuman.