GPS World

Blog

  • NDGPS Gasping

    RITA and the Coast Guard have a tough job ahead. Between them, the Department of Transportation’s (DOT’s) Research and Innovative Technology Administration and the multi-mission maritime service are trying to save a national differential GPS (NDGPS) program that faces termination next year.

    History. The U.S. Coast Guard (USCG) implemented the concept in the mid-1990s. Their requirement was for marine navigation, and the system now provides service for coastal coverage of the continental United States, the Great Lakes, Puerto Rico, portions of Alaska, Hawaii, and a greater part of the Mississippi River Basin. In a testament to NDGPS’s success, many countries around the world have duplicated the concept.

    Since the DGPS signal is broadcast in a 360-degree radius, inland users close enough to the USCG broadcasting station can receive and use the corrections. All of this happened before SA (Selective Availability) was turned off, so the accuracy improvement was staggering; from 100 meters down to 1-3 meters. Once inland users tasted the sweetness of the USCG DGPS system, a groundswell of support arose for expanding the system inland. The NDGPS system was born.

    Manufacturers began to integrate “Coast Guard” DGPS receivers into their products. Companies like CSI and Starlink offered after-market DGPS receivers to enable virtually any GPS user to receive the free DGPS signal, whether it was a $200 consumer GPS unit or a $10,000 submeter mapping receiver. Since then, tens of thousands of “Coast Guard” DGPS receivers have been sold around the world.

    Between the USCG, the Army Corp. of Engineers (USACE), and the DOT, 86 stations now blast out DGPS corrections free of charge that cover more than 90 percent of the U.S. landbase.

    Trouble. The program ran smoothly through the first half of this decade. Each year, a few new stations were added to expand coverage. The HA (High Accuracy)-NDGPS concept to provide decimeter-level positioning was proven to work. However, the rug flew out from under NDGPS last year when DOT’s Federal Railroad Administration (FRA) announced it would no longer sponsor NDGPS. NDGPS supporters had long hung their hats on Positive Train Control (PTC) as the killer application for NDGPS, as it would save the railroad industry billions per year and justify the cost of installing and maintaining the NDGPS. The DOT says the PTC doesn’t need NDGPS any longer.

    Two significant developments have reduced the need for NDGPS since the program began. The first is that autonomous (standalone) GPS accuracy is very good these days, on the order of a few meters. The second is the maturation of the Federal Aviation Administration’s Wide Area Augmentation System (WAAS).

    RITA to the Rescue. Last summer, with no FY07 budget for NDGPS, the scrambling began. The FRA washed its hands of NDGPS so the DOT transferred the program to a little-known agency called Research and Innovative Technology Administration (RITA). At the eleventh hour, RITA scraped up $5 million for NDGPS for FY07 — enough to operate and maintain the system until October 2008. $400,000 of that is allocated for “needs assessment.” In other words, they need to understand who is still using NDGPS and determine if the usage justifies future funding.

    The USCG (39 sites), USACE (9 sites), and DOT (38 sites) fund the 86 stations. USCG has said it would take over 12 of the DOT-funded sites if DOT decides not to fund the program. So the debate only involves about a third of the U.S. land mass. The USCG and USACE sites are not in jeopardy, as their requirements are considered safety-of-life for maritime navigation.

    Is there is a significant enough user base in the areas above to justify the roughly $7 million a year it takes to operate and maintain them? If there are only 1,000 users in those regions who use it regularly, that’s $7,000 per year, per user. That scenario doesn’t make sense. And it doesn’t even consider the cost of complete system build-out. Even at 10,000 users (a very unrealistic number), that’s still a cost of $700 per year, per user to the taxpayer.

    Who still uses NDGPS, anyway? That’s the magic question, and the DOT doesn’t know the answer. Presumably, determining that is part of the needs assessment, to be

    finalized in September 2007. I’ve heard speculators talk about agriculture being a big NDGPS user. While this might have been true five years ago, WAAS now dominates the ag market. Even CSI (now Hemisphere GPS), the largest producer of after-market “Coast Guard” beacon receivers and the leading GPS supplier to the ag market, has shifted its focus from NDGPS receivers to high-performance WAAS receivers.

    The forest products industry comprises some big users of GPS, but they’ve been post-processing for years, and some have even stopped doing that because autonomous GPS is sometimes good enough.

    What’s left is a fragmented group of utilities, federal/state/local government, engineering, surveyors, universities. and various -ologists. Honestly, as much traveling, conference attending, speaking engagements, and training as I do, I can’t recall the last person who told me they use NDGPS. That’s the fundamental problem.

  • GMV Buys Controlling Interest in Masisconvi

    Spanish technology conglomerate GMV has purchased a 66 percent controlling interest in Masisconvi S.A., another Spanish company that specializes in design and manufacture of electronic fare-collection systems.

    This purchase will allow GMV to incorporate Masisconvi’s wide range of electronic fare-collection systems into its own range of products in the passenger transport telematics area, where it has traditionally concentrated on GPS-based fleet management systems. This means that GMV can now offer fleet operating companies a complete, across-the-board coverage of all their possible needs in the field of information systems and communications, the company says.

    There is a growing trend of merging fleet management systems and fare-collection systems, according to GMV. Its takeover of Masisconvi will thus enable it to give a better service to its long-standing customers and develop lower-cost systems with improved service features to break into emerging markets, the company says.

    Masisconvi already has a strong foothold in some of these emerging markets, such as South America and North Africa, so its integration into GMV will not only boost its growth prospects but also improve the joint market position of both companies in the transport telematics market, according to GMV.

  • Honeywell Real-Time Locator for Manufacturing

    Honeywell this week introduced its Honeywell Instant Location System (HILS), a real-time asset management application that integrates a number of technologies, such as Ultra-Wideband, GPS, Wi Fi and RFID, with Honeywell’s process automation system, Experion Process Knowledge System.

    Installed at locations throughout a facility, receivers can pinpoint the location of an employee or piece of equipment and send the information to the HILS server, which directly feeds the information to the operator’s workstation, according to Honeywell. The receivers can transmit data wirelessly using Honeywell’s OneWireless network.

    One of the system’s major selling points is safety, the company says. Within seconds of a major plant incident, HILS can track employees and visitors through personal tags attached to their clothing and generate real-time mustering reports. These reports allow emergency responders to quickly obtain accurate head counts and locate missing or injured employees, according to Honeywell.

    Integrated with Experion, HILS can use equipment and personnel geo-location information to improve plant safety as well, the company says. For example, HILS can use interlocks to ensure dangerous procedures are only executed when personnel are a safe distance from a process unit or machinery.

    “This is the first real-time location system designed with the process industry environment in mind,” Jack Bolick, Honeywell Process Solutions president, said in a statement. “Integrating this technology with the control system produces a solution that gives manufacturers even greater awareness of what’s happening in their facilities. That awareness leads to safer and more efficient operations.”

  • Broadcom Gets Into the GPS Chip Biz

    Communications chip maker Broadcom Corp. today said it was acquiring GPS chip maker Global Locate Inc., a privately-held provider of GPS and assisted GPS (A-GPS) chips and software.

    Broadcom expects to pay approximately $146 million in cash for all outstanding shares of Global Locate when the deal closes. It anticipates closing on the acquisition during Q3, which ends Sept. 30. A strategic move that will likely prove important in the near future for Broadcom, it’s not a stretch for the company financially; its 2006 revenues were $3.67 billion.

    Broadcom, which specializes in wired and wireless technology and is noted for its RF tech, cited the growth in GPS applications, particularly in mobile devices, as the principal driver behind the acquisition. It noted that Global Locate silicon is found in not only mobile phones but also in personal navigation devices (PNDs) from TomTom.

    “With the acquisition of Global Locate, Broadcom will be the only semiconductor supplier in the world with top-tier customers in Bluetooth, Wi-Fi, FM radio and GPS, four of the key wireless technologies now being added to next generation mobile phones,” stated Robert A. Rango, vice president and general manager of Broadcom’s Wireless Connectivity Group. “We are also pleased to add Global Locate’s strong patent portfolio of over 175 issued and pending U.S. and foreign patents to our already robust patent portfolio.”

    Broadcom holds some 2,000 U.S. and 800 foreign patents with more than 6,000 additional pending patent applications, according to the company.

    Global Locate President Scott Pomerantz said he envisions a new generation of GPS chips coming from the merger—and the eventual appearance of Broadcom wireless technology in PNDs. “The combination of Global Locate’s navigation expertise with Broadcom’s well-known leadership in CMOS RF technology will enable Broadcom to develop a new generation of standalone GPS chips as well as GPS chips that incorporate other wireless standards, accelerating the adoption of GPS into all sorts of consumer devices,” he stated.

    Global Locate has focused on GPS chip and navigation technology since it was founded in 1999. The company is currently producing its third generation of GPS chips and has developed a worldwide GPS reference network that provides assistance data to its A-GPS-equipped chips via cellular data channels (GPRS or 3G), boosting performance and reducing the time required to determine a location by up to a factor of 100, according to the company.

  • MetaCarta to Provide the Oil and Gas Industry with Geographically Relevant Data

    MetaCarta, Inc., has announced an agreement with IHS Inc., a global provider of critical technical information, decision-support tools, and related services, to enhance MetaCarta’s Energy Geographic Data Module to provide information when searching for energy-related information specific to a location. Specifically, geologists and other E&P analysts using MetaCarta Geographic Text Search (GTS) and GTS geOdrive solutions will now be able to search for information such as blocks, licenses, oil fields, wells and basins found in IHS databases using the just-released MetaCarta IHS Global Oil & Gas GDM.

    IHS is a leading global provider of a broad range of aggregated, structured data used by the energy industry to study potential and existing oil and gas (O&G) reserves, as well as the transportation, contractual, competitive and other above-ground factors involved in bringing reserves to market. With the world’s most complete databases on wells, fields and other O&G entities, as well as geographic coordinates for these data types, IHS is the ideal choice to provide MetaCarta with a reference source to help guide smart-indexing of the vast amounts of unstructured data oil companies maintain and strive to fully leverage.

    MetaCarta GDMs are knowledge bases used to identify and disambiguate geographic references, assign latitude and longitude coordinates. GDMs contain natural language processing (NLP) logic, which is used to recognize the jargons and data types that represent geographic entities, disambiguate names, and establish greater geoconfidence and georelevance.

    “The alliance with IHS has allowed MetaCarta to develop an energy industry specific GDM utilizing the rich global knowledgebase of IHS,” said Ron Matros, president and CEO of MetaCarta. “Having the most accurate and comprehensive source of E&P information available with our search tools will allow our customers to more accurately pinpoint and collect location-specific information. Helping them get the information they need more quickly is critical to their business, particularly when they are making billion dollar decisions.”

    The Energy GDM is used with MetaCarta Geographic Text Search (GTS) as well as GTS geOdrive and contains thousands of place names, reference formats, and usage statistics particular to the energy industry. These include wells, blocks, MMS areas, oil and gas fields, basins, geologic provinces, and assorted other oil and gas features.

    “Energy companies face a tremendous knowledge-management challenge in order to take full advantage of the accumulated insights across their respective companies that relate to a particular geologic province, an individual well or other asset,” said Timothy Hopkins, vice president of Strategic Marketing at IHS. “With the MetaCarta offering, IHS customers will have the ability to search unstructured data, ranging from the proprietary archives of a retired, 30-year veteran geologist to the latest public press release on an emerging field, and choose from a list of geographically verified matching results. We think oil and gas companies will be delighted with this alliance and the added value it brings.”

  • Spirent Intros Customizable Software for GPS Test, Simulation

    Navigation and positioning test system supplier Spirent Communications this week introduced a software suite for the STR4500 GPS simulator, enabling users to generate their own test cases based on motion data that fits their specific requirements, the company said.

    Launched in 2001, the STR4500 provides pre-defined test cases for the testing of GPS receivers and systems to be replayed using a PC-based controller with RF signal generator hardware. Typical users of the STR4500 are involved with the selection, integration, verification or production test of GPS L1 C/A code systems, according to Spirent.

    The new SimPLEX45 software enables unique test cases to be generated, saved and run directly by the user. SimPLEX45 also enables user-defined motion-data to be used with atmospheric models and the environment around a vehicle, the company said.

    “This new software will enable our customers to drive a route and, using logged NMEA data, generate a trajectory for a test case,” stated John Pottle, marketing director for Spirent’s Wireless and Positioning Division. “The user also will be able to define the antenna pattern, atmospheric effect and obscuration due to buildings or other obstructions. We’ve built this capability into the STR4500 to provide our customers with reduced development times via improved tailoring of test scenarios to fit their specific needs.”

    The SimPLEX45 is available with new systems or as an easy to install upgrade to existing STR4500 users, Spirent said.

  • Antenna-Induced Biases in GNSS Receivers

    By Inder Jeet Gupta

    It is well known that the phase center of a GNSS antenna can vary with the satellite direction. This phase center movement leads to aspect dependent carrier phase and code phase biases in the satellite signal. For precise geo-location, one needs to characterize the antenna-induced carrier and code phase biases over the upper hemisphere. In the case of fixed pattern antennas (the antenna pattern does not vary with the incident signal environment) one can characterize the antenna induced biases a priori and use the data for corrections in the field. This is a standard practice in the surveying community.

    For antennas used with AJ (Anti-Jam) systems, however, a priori characterization of the antenna induced biases may not be of much value. These antennas consist of multiple elements. The signals received by various antenna elements are weighted and then summed together to form the composite output signal. The element weights depend on the incident signal (mainly interfering signal) scenario. As the incident signal scenario changes so do the individual antenna element weights which in turn will lead to different values for antenna induced carrier phase and code phase biases.

    As illustration, Figure 1 shows the antenna induced code phase bias of an AJ antenna over the upper hemisphere in the absence of all interfering signals as well as in the presence of two interfering signals.

    Figure 1. Antenna induced code phase bias (in meters) over the upper hemisphere. Left: no interfering signal; right: two interfering signals.

    In the figure, the center of the circle corresponds to the zenith and the outer ring corresponds to the horizon. The antenna induced code phase bias is plotted using a color scale in meters. Note that even in the absence of interfering signals, the antenna induced bias varies with the aspect angle. The presence of the interfering signals affects the antenna induced biases. This is true in the angular region surrounding the interfering signals as well as in the angular region away from the interfering signals.

    One can observe this more clearly in Figure 2 where the difference between the antenna induced code phase biases in the absence of interfering signals and in the presence of interfering signals is plotted using a color scale in centimeters. Note that the difference in the antenna induced code phase bias is quite significant, and one may not be able to obtain precise location without proper corrections.

    Figure 2. Difference (in cm) between the antenna-induced code phase bias in the presence of two interfering signals and in the absence of the interfering signals.

    The question is what could be done to minimize the effects of adaptive antenna induced biases in GNSS receivers. In my opinion, one can take the following two approaches. In the first approach (see reference), one predicts the antenna-induced biases on the fly. This approach requires knowledge of in situ volumetric patterns of individual elements of an AJ antenna over the bandwidth of GNSS signals as well as access to the antenna element weights. With a perfect knowledge of these quantities, one can come up with a very good prediction and can correct for the antenna induced biases. The sensitivity of the prediction to various parameters, however, needs to be studied.

    The second approach would be to develop novel weighting algorithms for GPS receiver adaptive antennas. Note that the current algorithms are mostly designed to either steer nulls in the interfering signal directions or maximize carrier to noise ratio in some sense. These novel algorithms should not only lead to improved carrier to noise ratio in the presence of interfering signals but should also make sure that the antenna-induced biases do not vary from their values in the absence of all interfering signals.

    Further, these algorithms should not use many degrees of freedom to meet the various constraints in that GNSS AJ antennas do not have many degrees of freedom. If most of the degrees of freedom are consumed to meet the above constraints then one will not have enough degrees of freedom left to null the interfering signals. This is a very challenging task, but leads to a good research problem!

    Inder J. Gupta

    Ohio State University

    References

    I.J. Gupta, et. al., Prediction of antenna and antenna electronics induced biases in GNSS receivers, Proceedings of ION 2007 National Technical Meeting, San Diego, CA, January 2007.

  • Survey Perspectives – May 2007

    The Dealer Shuffle

    Whether you live in London, Lagos, Lisbon, or Los Angeles, when you are looking to buy a survey instrument, most likely you have a “preferred” instrument distributor in mind. Maybe it’s the local Topcon dealer. Perhaps your Leica dealer has served you well. Or you might prefer the Trimble dealer in your area. All of the manufacturers have distributors signed up around the world. Some operate on a regional basis, serving several countries, while others serve one specific country.

    I raise this point because of recent, significant changes in the U.S. distribution of survey instruments. These include:

    • Topcon’s intent to acquire Sokkia (still subject to Japanese Fair Trade Commission approval).
    • Leica’s purchase of Allen Precision Equipment, Inc. (APE, Atlanta, Georgia), the largest nationwide catalog distributor of survey instruments in the United States and the largest Topcon distributor in the country.
    • Topcon’s purchase of Hayes Instrument Co., a regional and online distributor of Topcon, Magellan, TDS (Trimble), Sokkia, Nikon, and Carlson instruments.

    A little history. Generally, instrument distributors are independent companies that have distribution agreements with particular manufacturers. Sometimes, a distributor like APE will have agreements with several manufacturers. APE had (prior to being purchased by Leica Geosystems) distribution agreements with Topcon, Sokkia, and Magellan for GPS equipment.

    Another type of manufacturer/distributor arrangement is one like what Leica Geosystems has traditionally maintained in the U.S. They have one distributor that operates exclusively in a region, and no other distributor is permitted to sell in that region. In essence, the distributor is somewhat “protected” by Leica. In return for this protection, the distributor is not allowed to have a distribution agreement with a competing manufacturer.

    Outside of the U.S., there may be several distributors in a country, or there may be only one distributor for an entire country, or, in some cases, a distributor’s responsibility may include more than one country.

    Lastly, in other countries or regions outside of the U.S. where a suitable distributor does not exist or the country is very large, a manufacturer may set up its own regional office.

    The distributor is a very important part of the sales channel for the instrument manufacturer because, for the most part, the local distributor is the one that makes the sale and supports the customer. If the distributor does a good job of supporting the customer and building trust, the customer may be very loyal to the distributor. On the other hand, especially with GPS/GNSS equipment, the customer makes a significant investment training to learn a specific system. So are customers more loyal to the distributor or to the manufacturer?

    At the end of the day, I think they are more loyal to the manufacturer. Even though the customer may well prefer to work with a specific distributor, the significant investment in equipment and training in the manufacturer’s hardware/software trumps the relationship with the distributor. Not many customers are willing to retool their equipment, training, and procedures to stay loyal to a particular distributor.

    Back to current events. It’s been nearly two months since Topcon announced its intent to acquire Sokkia. There was some significance to the announcement in terms of brand differentiation and reconciling the Topcon and Sokkia distribution channels, but the synergy was plausible (refer to my March column for further details) and it didn’t upset the instrument distributor applecart in a significant way.

    Then along came Leica, who announced last week that it had acquired APE — a discount, nationwide, mail-order survey equipment supplier. APE is (was) Topcon’s largest U.S. distributor. In response to the purchase, Topcon announced it had severed its relationship with APE. In one fell swoop, a decades-long relationship was ended.

    On its website, APE stated that it “wished to continue representing all current product lines, including Topcon.” But the site goes on to say, “However, Topcon has chosen not to support our mission…” It doesn’t take a brain surgeon to understand why Topcon cut off the relationship.

    With its largest U.S. distributor cast away, Topcon was left with a big hole to fill. Within days of the Leica announcement, Topcon announced it had purchased Hayes Instrument Co. of Shelbyville, Tennessee. Hayes is a regional and online distributor of survey instruments which has garnered a reasonable reputation of providing quality technical support. Hayes is also a distributor of Magellan, Sokkia, TDS, Nikon, and Carlson. Topcon also announced Hayes will be opening an Atlanta, Georgia, office by the end of June. Clearly Hayes gives Topcon the springboard to expand their distribution quickly in the southeastern U.S. — where APE is the most dominant. This is damage control at its best and actually is a better long-term solution for Topcon, in my opinion.

    What I don’t get is how Leica is going to reconcile the APE purchase with its U.S. distributors. Leica has traditionally protected its distributor network fairly well, so on the surface the APE purchase seems really out of character. Perhaps APE was purchased to “fill in the blanks” where good Leica distributor coverage is lacking. Rumor has it there was a Leica distributor meeting last Monday (May 14th). It will be interesting to hear the fallout from that meeting.

    One thing is for sure: the dust hasn’t settled yet.

  • GPS Insights: Looking Aft, Looking Fore

    I recently attended the 23rd National Space Symposium in Colorado Springs, Colorado. As I walked around the exhibit halls one morning, I couldn’t help but think that of all the 140 exhibitors, there were only a handful, less than five actually, whose livelihood was not inextricably linked to GPS.

    To think that all these billion-dollar companies, and the start-ups as well, depended to such a great degree on a ubiquitous global utility that only became available on a global basis because of a seemingly insignificant, but in the end. deadly navigation error. Add to this the naked aggression and paranoia of the former Soviet Union and the benevolence and caring of a legendary U.S. President, and you have the beginnings of a tale that has changed our world forever, and whose final chapter may never be written.

    In this month’s column, you can read about:

    The past,
    the future,
    and the further-out future of GPS in the military-government sphere.

    You can go directly to each topic by clicking on the respective link above, or read the whole column by simply starting with the first one.

    The past

    It was almost 24 years ago that a commercial (passenger) Korean airliner inadvertently strayed into Soviet airspace because of a navigation error that probably occurred while the aircraft was still parked on the tarmac in Alaska.  Investigators now believe that the flight crew accidentally entered the wrong parking spot coordinates into their inertial navigation system) and therefore were off-course from the moment they departed. This original, seemingly insignificant error of only a few feet was magnified on their long over-water flight with no other enroute navigational aids to ameliorate their error. At that point in time the best INS was only good to about 1 nautical mile per hour for cross-track navigation accuracy and without updates could easily be ten nautical miles off after ten hours of flight time. The original position error resulted in an initial erroneous heading of 245 degrees and a prevailing westerly wind all conspired to place them over Soviet Territory without their knowledge.

    But wait, you say, the GPS constellation was in orbit and transmitting in 1983. Surely this would have automatically corrected the INS error; indeed it may have helped, if GPS had been available to commercial airliners at the time. But on this infamous date in 1983 GPS was restricted to government and military use. Originally designated the NAVSTAR (Navigation System with Timing And Ranging) Global Positioning System, GPS was developed by the U.S. Department of Defense, with the Air Force as the lead, to provide all-weather round-the-clock navigation capabilities for military ground, sea, and air forces.

    Only a handful of civilians were receiving the signals from space and then only for use in research and development programs. The general public knew almost nothing about the system, and certainly no commercial airlines were using it as an approved navigation aid. At the time of this incident, only eight GPS satellites were in orbit around the Earth. There should have been nine satellites, but the one and only GPS launch failure occurred in 1981. A full constellation is officially considered to be 24 satellites (four satellites in six planes). The United States current GPS constellation consists of 31 operating satellites of various ages and capabilities.

    Dr. Bradford Parkinson (Col, USAF Ret and Professor Emeritus of Physics at Stanford University) and I have discussed many times the fact that the United States and thus the world came very close to not having a GPS of any description. Among others, Brad was a visionary and was also the first USAF GPS JPO Director and as such was responsible for getting the first GPS satellites in orbit. In truth Brad had the responsibility for putting the whole GPS plan and strategic vision together and selling it to the government, and it almost didn’t happen. But that is a story for another time; suffice it to say we all owe Dr. Bradford Parkinson a great deal of gratitude for his dedication, professionalism, and, I suspect, persistence.

    So on September 1, 1983, Korean Air Flight 007, a Boeing 747, was on its own, navigating without GPS, and depending upon a perfectly good INS that had been programmed incorrectly and consequently informed the flight crew they were on-course and definitely not in Soviet airspace. Unfortunately, they were in Soviet airspace and had been for some time. Relations between the Soviet Union and Korea were not all that friendly in 1983. A few years before another Korean airliner had been shot down and crash-landed in the Soviet Union. Even though the Soviet interceptor pilots clearly saw the intended target carried the markings of a civilian airliner, (it’s hard for any pilot to mis-identify a 747), they followed orders (how many times have you heard that cliché) and blew the airliner out of the sky, just west of Sakhalin Island. KAL 007 carried 269 passengers and crew, including U.S. Congressman Lawrence McDonald. There were no survivors. An initial minor navigation error of a few feet, and 269 innocent civilians lost their lives, and as a consequence unknowingly ushered in the GPS Age for the rest of the world.

    Shortly after this tragic event, President Ronald Reagan went on national and international television to decry this barbaric act by the Soviet Union and to offer the world a solution: an absolutely free and no-strings-attached solution that should prevent such a tragedy from ever occurring again, at least from a navigation error. That solution was GPS, and it was a far cry from the GPS we know today — but that again is also a story for another time. It is enough to say that in this event and in many others throughout time, history has conspired to bring out the worst and the best of mankind, and consequently the world will never be the same.

    The Future

    So much for the history lesson. Lest I digress, there I was in Colorado Springs and about to see a navigation solution come to fruition that may have world-changing effects of its own. I first heard about Dr. James Spilkers’ new navigation idea about three years ago when we were sitting at breakfast together just before a GPS Independent Review Team meeting at IDA (Institute for Defense Analyses) in Arlington, Virginia.

    Dr. Jim Spilker (the father of the GPS signal as we know it today and the founder of Stanford Telecom), Dr. Brad Parkinson (former CEO of Trimble and former Chairman of the Board of Aerospace Corporation), Dr. Edwin Stear (former Senior VP and Chief Scientist at Boeing), Dr. Alison Brown (CEO of NAVSYS), John Darrah (former Chief Scientist of Air Force Space Command) and I were discussing Dr. Spilkers’ newest idea for navigation in areas where GPS provides a compromised solution, such as urban canyon situations, indoors etc.

    Jim’s idea was to use existing, unmodified television signals as an enhancement to GPS navigation. His thinking at the time was that since the location of television transmission towers is surveyed down to the centimeter, and the signal strength is strong, especially when compared to a GPS signal, then he should be able to determine lines of position, especially if he knew the time of transmission, and then use those LOPs to determine a position and/or to enhance GPS. At the time I remember that while we were all intrigued, we also came up with about twenty reasons why this would be difficult to accomplish, and besides — we had GPS, what more could we want?  Even the brilliant among us are at times just a bit naive.

    Fast-forward three years and Dr. Spilker, having overcome our paltry suggested technical and bureaucratic impediments, and more hurdles than I care to think about, is announcing the first navigation augmentation/enhancement product from his new company, Rosum: a chip-sized device that can be added to an existing GPS receiver, and uses existing unmodified television signals to determine a position.

    But from where do television signals originate today? Certainly from terrestrial sources, and then many are transmitted through cable systems, and at first glance that seems unhelpful, unless you consider where the majority of cable systems get their feeds (downlinks). From geosynchronous satellites of course, just like those of us that forgo the middle man, somewhat, and get our signals direct to the dish on the side or roof of our home or office. Over-the-air television transmitters are located on large earthbound transmission towers that typically put out a lot of wattage and hence signal strength over a 50- to 100-mile radius. Sounds a lot like a super-sized pseudolite to me. Now Jim’s idea starts to sound a little more plausible, doesn’t it?

    It is really intriguing how Jim and his cohorts managed to make this happen, and I will write more about it in the future. Hopefully, when I am in LA in a couple weeks time, I can get Jim to relate a little more about how it all came about and the hurdles that had to be overcome plus of course more about the capabilities of the system and Rosums’ future plans and products. Right now you can read more about it in a separate news item in this newsletter. You may also notice that Jim enlisted the help of those around the breakfast table that morning, and they are now either partners, supporters, or cheerleaders in this new navigation venture.

    Which of course brings us to our newest augmentation for the PHGPST (Perfect Handheld GPS Transceiver). You guessed it, unmodified existing television signals using the new Rosum chip to allow navigation in what are typically GPS challenged areas of reception and/or during times of jamming or interference.

    Many of you have written wanting to know just what all the components of the PHGPST are and indeed they are getting too numerous to mention in every column so we are in the process of establishing a separate place on the web page where these innovations, augmentations and additions will be listed and updated every month.

    The Further-Out Future

    In my list of notables at breakfast three years past, you will notice that I mentioned Dr. Alison Brown, the founder and CEO of NAYSYS, a twenty-year plus, growing boutique GPS think-tank and production facility located in the foothills of the Rocky Mountains in Monument, Colorado.  Alison and I have been friends for more than 17 years and have served on many studies and boards in the past, but lately have been slightly out of touch until I caught up with her at the Joint Navigation Conference in Orlando, Florida last month. Over dinner we discussed her support of Rosum and other GPS matters, but the one that intrigued me most and currently makes the biggest difference to our war fighters and allies is Talon NAMATH.

    This critical GPS enhancement allows our warfighters to better use the Air Force’s smaller and newest precision weapon, the GBU-39 small-diameter bomb. Talon NAMATH significantly boosts the bomb’s accuracy and reduces collateral damage to non-combatants. But again this program almost did not happen. With all the budget-cutting and bill-paying due to the war in Iraq and Afghanistan, this critical project was cut from the funding line and it was only through Dr. Brown’s persistence, and warfighter support, which included lots of letter writing and physically walking the halls of Congress, to promote an idea she really believed in, that Talon NAMATH managed to get out of the idea stage and into the field.

    Other supporters of numerous key innovative Talon programs like Talon NAMATH are the seven Air Force Battle Labs, which are now being shut down because of budget constraints. Six of the seven Battle Labs were established in July 2007 by directive of then-Air Force Chief of Staff General Ronald Fogleman, who wanted the Air Force to capitalize on innovation and have the ability to fast track programs crucial to our war fighters.

    Without exaggeration, I know I could write columns for the next ten years about Talon programs that have saved lives and innovations that have changed the face of warfare for our military members, not just in the Air Force, but across the DoD and for our Allies as well. I feel strongly that this is a monumental mistake and the Air Force will soon regret this decision. Shutting down an innovative and proven successful fast-tracking acquisition program while this country is at war is a disservice to our war fighters and one I predict the Air Force will re-energize either as reconstituted Battle Labs; or if that proves to be too embarrassing then under a different name, but with the same stated purpose.

    I am running out of time and room, but I do want to thank all those who continue to write and I want to remind you that I always answer my mail.

    See you right here next month.

  • Boeing Can Mix GPS with Iridium

    The Boeing Co. announced concepts for combining the GPS network with the Iridium low-earth orbit telecommunication network to improve accuracy, and signal acquisition in urban environments. Boeing executives delivered the briefing at the National Space Symposium for Pentagon and industry officials. There is no firm plan to turn it into a fielded system, however.

    “In any event, this would not obviate the need for GPS upgrades in any way,” said retired Maj. Gen. Craig Cooning, vice president and deputy general manager of space and intelligence systems at Boeing. “What it does represent is an elegant solution for augmentation of GPS.”

    According to the company, GPS signals could be acquired more quickly through amplification and rebroadcasting in a low-earth-orbit system.

    Iridium is a constellation of LEO communication satellites originally developed by Motorola Inc. in the late 1990s. When the system proved uneconomical, it was almost de-orbited early in the decade, until the Defense Department and private investors put in new money to keep the systems in orbit. The Iridium constellation would have to be replenished in order to support the IGPS concept, according to Boeing, but an upgrade of the system would be necessary in any event by 2014.

  • New Beidou Satellite Launched

    China launched its fifth Beidou/Compass navigation satellite on Friday, April 13.  The initial orbital elements (inclination = 55.0°, eccentricity = 0.62, mean motion = 3.84 orbits per day) may indicate that this is not another GEO satellite but rather the first of the MEO satellites.

    Meanwhile, it seems that NORAD had “lost” the 4th Beidou satellite for awhile. Launched on February 2, the satellite reportedly had a problem with a stuck solar panel which needed to be fixed before the satellite could be transitioned from its geostationary transfer orbit to its intended geostationary location. The last publicly released element set for this satellite had been dated 8 March 2007. Perhaps this was the day the Chinese started to move the satellite to its geostationary position.

    NORAD released an element set for the satellite in its near geostationary orbit. NORAD is currently reporting the satellite to be in an inclined orbit (6.3°) with a sub-satellite longitude of about 144°E. The latest Beidou/Compass might not be heading for GEO but either to an inclined geosynchronous orbit or MEO, similar to that of GPS and GLONASS satellites.

    The Chinese have talked about various Beidou/Compass options:

    1. 4 GEO + 9 inclined (50°) geosynchronous
    2. 4 GEO + 12 MEO (55° x 20,200 km)
    3. 30 MEO (56° x 21,363 km)

    In one of their ITU filings, the Chinese referred to some of the satellites as Compass-M.

  • EGNOS Performs Well in Flight Trials

    The European Geostationary Navigation Overlay Service (EGNOS) recently passed flight trials in Limoges, France with flying colors, according to the European Space Agency (ESA).

    EGNOS, a venture between the ESA, the European Commission and Eurocontrol, is the first step in Europe’s satellite navigation plans, paving the way for Galileo. EGNOS supplements GPS data, offering more accurate vertical positioning data to pilots, similar to systems already in operation in the United States. The system can provide a precision of better than two meters, according to the ESA.

    In the most recent EGNOS flight trials, a French civil aviation authority test plane was specially equipped to make tests using EGNOS at an airfield in Limoges, France. It made a number of approaches and landings using the new procedures, in each case aligning itself with the runway’s axis and then following a descent path to touchdown.

    Inside the plane, which is normally used for calibration of airport systems in France, the method of analyzing the quality of the EGNOS signals was done by comparing the landing phases guided by satellite with landings using traditional means, such as the plane’s Instrument Landing System (ILS).

    The results of Limoges trials demonstrate again that EGNOS signals allow approaches and landings that meet the safety standards that govern international air traffic, the ESA says.

    One of the main advantages of EGNOS is that it is available everywhere without the need for ground infrastructure and it provides vertical guidance procedures for every runway, the ESA says. Furthermore, the cockpit data display is the same as that of ILS, so there are no familiarization problems for the pilots and no additional training costs.

    Currently in pre-operational service, EGNOS will be certified in 2008 for safety-of-life applications such as air traffic control. It will be comptible and interoperable with similar systems elswhere in the world, according to the ESA.