With nearly 60 GPS engineers and scientists, the Jet Propulsion Lab (JPL) is one of the biggest GPS R&D centers in the world today. It operates as a division of the California Institute of Technology (Caltech), which manages the lab for the National Aeronautics and Space Administration (NASA).

Among other things, JPL operates the Global Differential GPS (GDGPS) system, which sells technical services and data and licenses software. The GDGPS system within JPL employs a vast, worldwide network of more than 100 L1/L2 GPS reference stations owned by itself and its partners.

Each reference station streams GPS measurements back to the GDGPS Operations Centers once per second. Data is then processed and analyzed in real time. Talk about redundancy — each GPS satellite is always observed by at least ten reference stations, and twenty-five is typical. Read more

It’s easy to get lost in JPL’s wide array of GPS product and service offerings, so I’ll try to stick with the part that’s closest to survey and construction.

Among other activities, JPL has people dedicated to monitoring and modeling the atmosphere — especially the ionosphere, which strongly impacts GPS measurements. They provide real-time, global maps of the Total Electron Content (TEC) used for L1 differential corrections around the world (think SBAS like WAAS and MSAS) and also for predicting ionospheric storms.

Dr. Michael Whitehead of Satloc, Inc. (now a division of Hemisphere GPS, Inc.), lead the first Wide-Area Differential GPS (WADGPS) commercial ventures to license JPL’s clock/orbit correctors and iono modeling services. This was back in the mid-90s, and Satloc’s target market was agriculture. Remember, this was before Selective Availability (SA) was turned off, so without a source of corrections, horizontal GPS accuracy without augmentation would routinely blow out to 100 meters. With its system, Satloc was able to deliver sub-meter L1 corrections to users via communications satellite.

“They (JPL) provided core technology. It worked great. The accuracy was there,” said Whitehead.

Whitehead said Satloc operated its own GPS reference network and internal software for generating corrections, but it also used JPL’s service to provide system redundancy. The Satloc system was set up to use corrections from either system (Satloc or JPL), and could automatically switch between the two systems.

The Satloc network was eventually sold to Fugro/OmniSTAR, another WADGPS service provider that integrated JPL data into its product offering. Hemisphere GPS/Satloc products now rely on WAAS (Wide Area Augmentation System) for their source of corrections. WAAS is built on core JPL technology, a predecessor of the GDGPS software. According to Whitehead, WAAS is very similar to the system that Satloc originally developed.

Fugro/OmniSTAR

Fugro/OmniSTAR operates its own GPS reference station network (over 100 worldwide, with 21 of those in North America) and has offered a WADGPS service in certain regions of the world dating back to the late 80s on a subscription basis. Until the late 90s, OmniSTAR/Fugro was a “one-trick pony,” offering a sub-meter “VBS” service for L1 GPS receivers. This is based on its worldwide network of GPS reference stations. Since then, the company has expanded its services in response to demand for greater accuracy and system redundancy.

Now, Fugro/OmniSTAR offers two additional levels of service: HP and XP. Both require the user to have a dual-frequency receiver (L1/L2). The upside is that the HP service provides +/-10cm horizontal accuracy using carrier phase (a sort of float solution). The HP service is based on Fugro/OmniSTAR’s proprietary GPS reference network and software. HP service is available in various regions throughout the world such as North America, parts of South America, Europe, the Middle East, Central Asia, and Australasia. The HP service is reference-station-dependent, meaning that the performance degrades as the user moves farther away from the nearest reference station (with a 300-mile limit).

Fugro/OmniSTAR’s other precise service, XP, is based on data licensed from JPL. The XP service offers horizontal accuracy of +/-15cm. The HP and XP services are similar in accuracy, but the JPL-based XP service offers global service rather than a regional service like HP. The difference is that while the HP service is baseline-dependent, the JPL-based XP service is not. That enhances Fugro/OmniSTAR’s coverage in remote locations where reference station coverage is sparse.

NavCom Technology

A leading-edge GPS design company licensing data from JPL is NavCom Technology, Inc., from Torrance, CA. Although the company name isn’t well known in the Survey/Construction industry, many of the engineers at NavCom are the same ones that designed the original Leica survey receivers while they were at Magnavox. There is some pretty high-end GPS design talent there — enough that John Deere Company bought NavCom, which now operates as a wholly owned subsidiary of Deere.

NavCom created and operates a GSBAS (Global Satellite-Based Augmentation System) called StarFire. While NavCom operates its own network of 20 worldwide GPS reference stations, it also has license agreements with JPL for reference station data and certain software. NavCom then refines and optimizes the data for NavCom receivers and distribution via the StarFire network. The result is that StarFire can deliver horizontal accuracies in the sub-10cm range after initialization.

NavCom has also created an interesting innovation it calls RTKExtend. Users of traditional RTK systems know that when the data link is interrupted, RTK operations are halted until the data link can be re-established. However, NavCom has combined traditional RTK with its StarFire network to assist RTK users. Users begin work using the traditional base/rover RTK configuration. If the data link is interrupted, the NavCom receiver automatically transitions to use the StarFire network, so the user can continue to operate at the centimeter level for up to 15 minutes.

Satloc, Fugro/OmniSTAR, and NavCom are just a few examples of commercial organizations that have successfully utilized JPL’s leading-edge GPS technology. There are also applications outside of the high-precision industry, such as mobile phone service providers licensing JPL to provide A-GPS data for E-911 anywhere in the world. With its unique global reach, JPL’s technology enables precision GPS applications even in regions of the world that lack infrastructure. It’s truly impressive to realize that decimeter-level positioning is available in most places in the world today; it’s just a matter of how to deliver the corrections. With the proliferation of wireless communications, even this problem will eventually be solved.

DOT Throws NDGPS a Life Preserver

It appears the US Department of Transportation has bought the Nationwide Differential GPS system (NDGPS) another year. The FY09 Presidential Budget Request was released earlier this week, and it contains a line item in the Research and Innovative Technology Administration (RITA) budget for NDGPS in the amount of $4.6M for operations and maintenance of the current system until October 2009. There is no budget item for the planned build-out of NDGPS. The budget request is subject to approval by Congress, but most likely this will go through.

The funding request is neither a thumbs-up nor a thumbs-down for NDGPS. The FY09 $4.6M budget request for NDGPS merely means that the DOT hasn’t figured out what to do with NDGPS yet, and the pain of having to fund a decommissioning program outweighs the $4.6M to keep it running for another year.

I think it’s the right decision. That may be intriguing to some of you who have followed my criticisms, but they have principally been directed at the stewards of NDGPS, not the program itself. RITA, regardless of how incompetent it has been at trying to understand this, needs more time to have a chance of comprehending how NDGPS is used.

Last year, RITA was funded $400,000 for a “needs assessment” of NDGPS. In other words, the administration is supposed to study and understand who is using NDGPS. Their primary attempt at this was opening a formal docket for accepting public comment last fall. You can read the Federal Register Notice here.

With an initial deadline for public response of October 1, 2007, the responses were very weak; about 30 comments were collected. The deadline was ignored by DOT, and more comments have been trickling in, with the last one posted January 28, 2008. As of February 4, 2008, there were 124 comments. However, because the explanation in the docket was written so poorly, some of the comments are not about NDGPS and obvious confusion exists between NDGPS, CORS, and OPUS. I read through every comment submitted.

After culling out the statements from by people who didn’t understand NDGPS or made meaningless comments, nearly one-third of the responses in favor of NDGPS were from National Park Service employees. Several submissions represented federal and state government users, from agencies such as the USDA, state DNRs, state DOTs, state geodetic surveys, and county and local governments. It’s hard to assign a number of users to those sorts of submissions, though. For example, in the USDA comment, it claims to have 7,000 GPS receivers in use nationwide, but you and I know that only a very small percentage use the NDGPS stations being considered for decommissioning. The USDA commenter also wrote that the loss of CORS “would have a severe impact on high-accuracy positioning.” Well, that’s not the case, so discounts the credibility of the agency’s support.

It’s sad that a pioneering GPS program such as NDGPS is being treated as it is today. Whether you support NDGPS or not, it has earned a fair shot — and it’s not getting it. That’s why I agree with the decision to fund it for another year while RITA pulls itself together. It will be very interesting to read the results of RITA’s $400,000 “needs assessment” report that was due to be completed January 30, 2008. If it’s anything like the joke of a report entitled “NDGPS Study” that was presented last fall at the CGSIC meeting in Ft. Worth, just go ahead and shoot me now.

Since the RITA docket failed to communicate to the public just what effect the loss of 26 NDGPS site would have for both NDGPS users and CORS/OPUS users, I’ll attempt to spell it out here, as clearly and concisely as possible.

What’s at Stake?

If the 26 NDGPS sites cease to operate, you will not be able to receive DGPS corrections from these sites.

Map of current DGPS and NDGPS sites:

Map of DGPS system minus the 26 NDGPS sites:

Following is a list of the 26 NDGPS sites on the chopping block:

• Hackleburg, AL (HAC)
• Flagstaff, AZ (FST)
• Bakersfield, CA (BKR)
• Chico, CA (CHO)
• Essex (Fenner), CA (CAE)
• Pueblo, CO (PUB)
• Macon, GA (MCN)
• Hagerstown, MD (HAG)
• Pine River, MN (PNR)
• Billings, MT (BIL)
• Polson, MT (PLS)
• Greensboro, NC (NCG)
• Medora, ND (MDR)
• Whitney, NE (WHN)
• Albuquerque, NM (ABQ)
• Austin, NV (AST)
• Hudson Falls, NY (HDF)
• Klamath Falls, OR (ORK)
• Seneca, OR (ORS)
• Hawk Run, PA (HRN)
• Clark, SD (CLK)
• Dandridge, TN (TND)
• Hartsville, TN (HTV)
• Summerfield, TX (SUM)
• Myton, UT (MYT)
• Spokane, WA (SPN)

What Alternatives Exist?

If you depend on one of the above sites for DGPS corrections (not CORS or OPUS but beacon corrections), what are your alternatives if the site is shut down?

1. The easiest choice is to switch to WAAS as a correction source. Most receivers are WAAS-enabled and, like NDGPS, it’s free. However, you’ll need to reconcile the horizontal datum difference between the two. NDGPS uses NAD 83(CORS96) and WAAS uses WGS-84(G1150). I’ve done this many times; it’s not difficult, but it needs to be done or you will introduce 1+ meter error.

Caveat emptor. Some GPS receivers handle WAAS better than others. Check for firmware updates from the manufacturer of your equipment. Also, some receivers don’t handle WAAS well when you are working under tree canopy or around buildings.

2. If you don’t require real-time corrections when you’re in the field, then you can choose to post-process your data. Post-processing software is fairly automated these days, but inconvenient nonetheless.

3. If you absolutely need submeter positioning in real time and your receiver isn’t capable of providing that via WAAS, there are several options.

OmniSTAR is a commercial provider of submeter and decimeter corrections. It may or may not work where you work, however, because it’s got a line-of-sight limitation. If you’ve got a GPS receiver with an OmniSTAR receiver already built in (e.g., Trimble ProXRS), then it would be relatively painless for you to try it. I seem to recall that OmniSTAR has a trial program of sorts.

RTK networks are popping up all over the country. Some are able to provide submeter corrections to mapping receivers via a mobile phone. Mobile phone data plans are relatively inexpensive, and you may even be able to rent one from a local GPS dealer when you need it. Most RTK networks charge a subscription or membership fee, but it doesn’t hurt to ask how they could accommodate you.

Believe it or not, it’s not that hard to take control by setting up your own portable base station and broadcast corrections. Yes, you need two GPS receivers (one to generate the corrections), and you need a way to get data from one receiver to the other (UHF radios, spread-spectrum radios, NTRIP, etc.), but it’s doable. It’s a little painful to put the system together, but once you’ve done it, you’re set for life. You don’t rely on anyone else.

Effects on CORS/OPUS Users

In shutting down the 26 NDGPS sites, one piece of collateral damage would be the loss of CORS and OPUS for post-processing using those sites. Is it an issue? For CORS and OPUS users, it’s not; for OPUS-RS users, it might be. I’ll explain.

First, let’s get definitions out of the way. When I write CORS, I’m referring to accessing RINEX data for L1 C/A post-processing. That’s you folks who use a Trimble Pathfinder, ProXR, etc., and post-processing the data to obtain meter-level accuracy. When I write OPUS and OPUS-RS, I’m referring to the National Geodetic Survey’s Online Positioning User Service, whereby you submit L1/L2 data and have their OPUS post-processing software reduce your data to centimeter-level accuracy and return corrected coordinates to you.

For CORS users, the loss of your favorite NDGPS site won’t affect you, except that you’ll have to use either the next-closest CORS site or a regional reference station from the US Forest Service or state/local government. There are a ton of them around, so that shouldn’t be a problem.

For OPUS users, the loss of the NDGPS sites won’t affect you. OPUS provides good results when using sites that are 500, 600, and even 700 kilometers away. If you go to http://www.ngs.noaa.gov/OPUS and click on Recent Solutions, you’ll see solutions from as far away as South America. I interviewed Dr. Dru Smith from the National Geodetic Survey in September 2006, and even back then, he said the days of needing to “use your favorite CORS” station are over. The OPUS software, he said, is designed such that an increased baseline distance is not an issue to be concerned with given the high density of CORS stations.

For OPUS-RS users in certain areas, the loss of the NDGPS sites may affect you. The difference between OPUS and OPUS-RS, to the user, is that OPUS occupations require a minimum of two hours, whereas OPUS-RS only requires a minimum of 15 minutes of occupation time. But a limitation of OPUS-RS is that the user position must be within 250 kilometers of three CORS; those three CORS stations must surround the user position (think good geometry). In certain regions, that will create a problem for users.

NGS has already conducted preliminary studies, determining that CORS coverage for OPUS-RS users in some regions of the country is deficient even with the NDGPS sites still active. Northern Maine, northern Minnesota, North and South Dakota, Iowa, Nebraska, Montana, Wyoming, Idaho, and northeastern Washington have been identified as deficient regions for OPUS-RS users, according to Dr. Richard Snay of NGS. Decommissioning the NDGPS sites in those areas would magnify the problem. On a positive note, Snay did say that NGS will soon be adding several CORS from the Minnesota Department of Transportation, so that will help OPUS-RS users in the region.

What’s the solution for the OPUS-RS users who would be affected if the DOT decommissions the 26 NDGPS sites? The easiest, and only, solution I’d recommend is to revert back to using the original OPUS program. This means planning for two-hour occupation times instead of 15 minutes. Secondly, I’d start lobbying your state DOT, county, and whoever else might be interested in setting up a cooperative CORS site in your area.

In summary, the impact of shutting down the 26 NDGPS sites has a minimal impact on CORS/OPUS/OPUS-RS users.

Back to the Budget

The FY09 NDGPS funding request is still only good enough to stop the bleeding for another year; it doesn’t solve the problem. When its study is completed, I seriously doubt RITA is going to find enough transportation applications to justify continuing to fund NDGPS under the DOT umbrella. Realistically, it’s going to be up to federal and state government users in the affected regions to pony up the funding. You can bet that no private entities are going to contribute significant funds, if any at all. They’ll find another solution before going down that road

Listed below are some of the major government supporters (or associations who represent government agencies) that submitted public comments in support of NDGPS. I think it will be up to them, and others, to come up with at least the Operations/Maintenance budget of approximately $5 million annually to sustain (not build out) the NDGPS as it is today.

• USDA (including US Forest Service)
• National Park Service
• Farm Service Agency
• Bureau of Land Management
• Maryland DNR
• Iowa DOT
• South Dakota Association of Local Government
• California DOT (CALTRANS)
• State of South Dakota
• Association of American Railroads
• North Dakota DOT
• North Carolina Geodetic Survey
• North Dakota Water Commission
• Washington DOT
• Idaho DOT
• National Association of State Departments of Agriculture
• Virginia DOT

3D Machine Control

One of the hotter topics in the construction industry these days is GPS/GNSS. If any of you attend the World of Concrete exhibition in Las Vegas, you’ll see many examples of how GNSS is being implemented in construction environments. The exhibition is expected to attract more than 1,700 exhibitors and 90,000 attendees this month. I’m sorry I’ll miss it this year, but if you do attend, you’ll find the usual GNSS (and related) suspects exhibiting: Topcon, various Trimble divisions, Leica, Sokkia, Seco Mfg, CST/Berger, Berntsen, etc.

Although the U.S. real estate construction market is clearly slowing (or shall I say dying?), the commercial construction market seems to be holding its own for the time being. The demand for construction automation equipment is still there, but I hear more about construction (and surveying) outfits wanting to rent GNSS equipment as opposed to buying it. This makes sense, as confidence in the economy is clearly waning.

Regardless of construction industry trends, there’s no lack of equipment automation opportunities (GNSS-wise) in the construction industry. Of course, precise positioning (topo surveys, construction staking, grade checking, establishing control, etc.) is one area of opportunity, but there’s also not-so-precise positioning, like navigating to job sites (a la “In 500 feet, turn left on Main Street”) and asset tracking (“Yes, Mr. Job Superintendent, we delivered that 2,500 feet of 2-inch PVC this morning at 9:10am; would you like to know exactly which staging area we delivered it to?”).

But perhaps no GNSS automation is causing such a stir as 3D machine control. Actually, it’s not 3D machine control itself, but the matter of who is technically and legally is able to provide the site data that’s used by the 3D machine control equipment.

I think the issue can be summed up in three statements:

1. Construction firms need 3D site data in order to use their 3D machine control equipment.

2. Engineering firms, those responsible for generating the plans, are hesitant to give up/generate the 3D site data because they’re concerned about exposure (errors and omissions).

3. Surveying firms, specifically those specializing in construction staking, aren’t too hot about the 3D machine control concept because it significantly reduces the need for construction staking.

I don’t think anyone knows how this is going to shake out yet, but I believe one thing is certain. The value proposition of 3D machine control for construction firms, when used on the right type of projects, is just too great for it to be ignored. As the old saying goes, just follow the money. As long as you believe that, then the responsibility of the 3D data preparation really doesn’t matter, because it’s going to happen. Granted, there might be a catfight before it’s all through, but it will be resolved.

I’ve sat through a couple of friendly discussions on this subject, must recently at the Trimble Dimensions conference, where folks — construction firms, engineers, and surveyors — had a chance to voice their opinions. I’ve also had the opportunity to work with a number of each of them. One recurring theme that stands out in my mind is the efficiency and resolve of construction companies. Well, maybe not efficiency at times, but certainly the resolve. They understand, as much as anyone, that time is money.

That’s a major reason they are so gung-ho on 3D machine control. The idea of not having to wait around for someone to pound or re-stake grade stakes or construction limits or whatever is like RTK: it’s addictive. In fact, contrary to what some may say, construction superintendents and operators are quite resourceful.

“Joe Engineering Co. said they weren’t going to provide the 3D site data?” Well in that case, Mr. Job Superintendent might just turn around and digitize the 100-foot-scale paper plans they’ve got. Two days later, they load up the 3D site data, and they are off and running.

I know, I know. That raises all kinds of issues. Copyright infringement, liability, etc. By the time you’re done listing the issues and debating them, the construction company has finished the project and moved on to the next job. Is that right — or even legal? Maybe, or maybe not, but that’s reality, at least for now.

The Solution?

To quote Chris Matthews from his book I just read, entitled Life’s A Campaign, “The people who show up get the chances.” I think it’s a mistake for engineers/surveyors to stonewall construction firms and attempt to withhold 3D site data. I think they’ve got to stay in the game and keep the data flowing.

Is it business as usual and just pass the DWG, Ma’am? No, of course not. There’s even an opportunity for generating revenue. Contractors are going to pay for 3D site data that has been certified for 3D machine control, if their other choices are using a dated, non-certified DWG file that’s passed through ten different e-mail threads, or trying to digitize paper site plans.

The game is changing. Are you going to show up?

GPS

On the GPS front, I’m going to paraphrase, plagiarize, and otherwise copy from my fellow newsletter editor Don Jewell, who writes the Military & Government PNT newsletter. He spent decades on the inside looking out (think Lt. Col. Jewell) and offers interesting perspectives.

First off, after a relatively quiet period since launching the first new modernized satellite, the Block IIR-M (offering the new L2C signal), in September 2005, there has been a flurry of activity and announced activity in the past 13 months.

First — Sept. 25, 2005. PRN 25/SVN 53 . Slot C4.
Second — Sept. 26, 2006. PRN 31/SVN 52. Slot A2.
Third — Nov. 19, 2006. PRN 12/SVN 58. Slot B4.
Fourth — Oct. 17, 2007. PRN 15/SVN 55. Slot F2.
Fifth — Dec. 20, 2007. PRN /SVN 37. Slot C1.

Remember, a total of eight IIR-M satellites were built; the GPS Wing says the remaining three will be launched in 2008. One of the remaining Block IIR-M satellites has been modified by Lockheed Martin, with the capability of broadcasting an L5 non-operational test signal. The L5 operational signal is planned for the next-generation GPS satellite, the Block II-F. The first II-F was due to launch in 2008, but this doesn’t seem likely…and it seems less urgent since the IIR-M modified to broadcast an L5 test signal will secure the signal spectrum. Securing a signal frequency, especially with the competing satellite systems from other countries is not a simple task — but we’ll save that discussion for another time.

So, from all public sources of information available, the current IIR-M launch schedule looks something like this:

Sixth — Mar. 13, 2008.
Seventh — June 2008.
Eighth — October 2008.

This is the flurry of activity I was referring to. Essentially, five launches within a twelve-month period.

And this is where I bring in some of Don’s valuable info:
“In the current constellation there are indeed 32 satellites, and normally that would be nearly the perfect constellation configuration, but a few of the older satellites and payloads are ‘single string’ in space parlance or on their last legs and require substantial care and feeding, including power management, by the very talented personnel/crews at the 50SW (Space Wing), 2SOPS (Space Operations Squadron) at Schriever AFB in Colorado, and the intrepid engineers at the GPS Wing at Los Angeles Air Force Base in California.

“Each GPS satellite is designed with an ‘A’ and a ‘B’ side that approaches 100% redundancy for critical systems. Several of the satellites were switched to the ‘B’ side years ago and have significantly outlived their design life, which differs with each series of satellites launched.

“Therefore, don’t be surprised that as we launch more and more GPS satellites (IIRM+s), the number of active satellites in the constellation stays the same. Since we have 32 satellites on orbit, remember that is almost the optimum number, we are in a replenishment mode, and attempting to maintain the constellation at the optimum number while still adding new capabilities, or modernization; a good thing for war fighters when we are involved in several hot conflicts/wars around the globe.

“Now, what about the nine possible failures of the IIA series GPS satellites? The satellites in question are all at or beyond their design life and have critical failures; they are being kept alive by heroic means that require exceptional amounts of time and money. If the worst should happen and all nine IIA birds fail, then we would be down to 23 satellites which is far from the optimum number — but remember we will be launching the rest of the IIRM satellites at the same time and that should put the number of on-orbit GPS satellites at about 29. Colonel Dave Madden says the goal is to stay as near the optimum number as possible but to certainly never go below 27 satellites if possible.”

So, I think the conclusion to be drawn here is that those of you who are experiencing “PDOP spikes” during the day that prevent you from being productive when using RTK will continue to experience those, even with the new GPS satellite launches. I mention RTK because that is the technology that relies most heavily on having a consistent number of observables (6+). Static post-processing users are affected, but to a lesser extent.

The bottom line, and I’ve made this point many times in the past, is that if you want more satellites observable, the solution in GLONASS. That subject transitions nicely into my next discussion.

GLONASS

Why is it that we always seem to hear about GLONASS satellite launches, but the number of operational GLONASS satellites never seems to increase significantly (and even decreases)? The answer is that legacy GLONASS satellites had a poor operating life span — well under four years. The good news is that the new GLONASS-M satellites they’ve been launching have a “guaranteed” operating life of seven years.

Since I touched on this subject last fall, six more GLONASS-M satellites have been launched: three on October 26, 2007, and another three on December 25, 2007 (Russia’s Christmas gift to GNSS users). Two of the October 26 satellites are operational, so there are four left in orbit and pending operational status. There are twelve operational GLONASS satellites as of December 29, 2007. This could increase to sixteen in the next couple of months as the four satellites already in orbit are made operational. That would be, by far, the most operational GLONASS satellites we’ve seen in recent years.

This is great news for GPS/GLONASS users. Actually, GPS/GLONASS users gain more marginal benefit from GLONASS satellites than from GPS satellites because GLONASS satellites are on different orbital planes than GPS, and therefore, offer a better opportunity to increase the quality of the satellite geometry (e.g., decrease your PDOP).

As in 2007, six GLONASS satellites are scheduled to launch in 2008. This is good, but we’ll probably see some legacy GLONASS satellites fail also. There are two that are past their fourth birthday, and three that just turned three years old last month. In the best-case scenario, we could see 22 operational GLONASS satellites a year from now. In the worst-case scenario, I can’t imagine having less than 14 or so available to us. Not bad considering we had as few as nine available during certain times in 2007.

Although it’s been a rough ride at times, I continue to be a passenger on the GLONASS bandwagon. You can keep up with the GLONASS constellation status by visiting

this Russian Space Agency website.

Topcon/Sokkia Merger

 

Switching gears a bit, we move on to December 10, 2007, when the Japanese Fair Trade Commission (JFTC) approved the Topcon/Sokkia merger. JFTC approval was needed because both companies are headquartered in Japan. The only constraint is that “non motor-driven total stations” sold in the Japanese market must be sold through a third party “in order to clear antitrust concerns posed by the JFTC,” according to the Topcon press release. You can view the entire press release here.

I think this is a boon for both Topcon and Sokkia. It gives Topcon another distribution channel to push its GNSS technology. It gives Sokkia access to a broader range of GNSS technology than they have with Point, Inc., their joint venture with NovAtel. Also, Leica recently bought NovAtel. Since Leica is a direct Sokkia competitor, it put Sokkia in a difficult position if the Topcon merger didn’t go through.

I don’t think this particular merger is a bad thing for the user community. My guess is that you’ll see some dual branding, like you did when Trimble acquired Spectra Precision. Even though it’s all Trimble technology, it markets the EPOCH GPS system under the Spectra name for the budget-minded user while still maintaining higher selling prices for its technology under the Trimble brand name. I could be wrong, but I bet Topcon/Sokkia does something like this.

ION GNSS 2007 Report

I hope some of you had a chance to read my ION GNSS conference blog, as well as those of my fellow editors who attended the conference. I think Editor-in-Chief Alan Cameron’s brainstorm about this was very good, and I expect we will repeat next year. If you missed it, you can still view it on the GPS World Web site. It’s worth a few minutes of reading to get the flavor of what the hot issues were.

For this newsletter, I’m going to hit the highlights and comment on them, so fasten your seatbelt.

CGSIC  Meeting

Every year, the CGSIC (Civil GPS Service Interface Committee) holds two days of meetings before the ION GNSS conference; this year was no different. There were status briefings on the different programs, such as GPS and GPS modernization, GLONASS, Galileo, Compass, QZSS, WAAS/EGNOS, NDGPS and other activities. The CGSIC provides PDFs of the presentation on its site.

Satellite launch schedule. The GPS Wing plans to launch the rest of the IIR-Ms in FY08. One was launched last week, on October 17. Its designation will be PRN 15/SVN 55 when it’s declared operational in early November.

The next launch is scheduled for December. Then March 2008. Then June 2008. The launch schedule for the last one hasn’t been announced yet.

However, the GPS Wing said that they plan to launch the first Block IIF satellite (with L5 in addition to L2C) before they launch the last IIR-M. This will be interesting, because rumor has it that the Block IIF is waaaay behind schedule and has almost no chance of being ready in 2008.

Another interesting twist is that Lockheed was awarded a contract last Spring to enable a IIR-M satellite to broadcast an L5 test signal. Something about protecting the L5 frequency with the ITU (United Nations International Telecommunication Union) until the first IIF is ready.

GLONASS. For you GLONASS users (or potential ones), the future is brightening somewhat. I’ve been touting GLONASS for some time, and the reliability of operational satellites has been disappointing. One could say that this is due to the legacy satellites, which are averaging well under four years of operational life, but that isn’t the whole story. While the newer GLONASS-M satellites supposedly have a seven-year life guarantee, the track record for the GLONASS-M really isn’t that great. For example, of the three GLONASS-M satellites that were launched in December 2006, only one is operational today.

There are seventeen GLONASS satellites in orbit. Only eleven are operational. Seven are the newer GLONASS-M models and four are the legacy models.

The bright spot is that six more GLONASS-M satellites are scheduled to launch by the end of this year—three this month and three more in December. The number of usable GLONASS satellites really needs to improve. GLONASS can’t seem to get above 13 operational satellites, and many times it’s been down to 9. Don’t count on the six new satellites to be operational in the near future. Sometimes, it takes more than six months after launch for them to be declared operational. I wish it wasn’t the case, but that’s a fact. Sometimes, I beat up on the GPS Wing for their slow pace, but after they launch one, it’s operational within thirty days—and it’s reliable.

The GLONASS folks also announced that they are migrating the datum used by GLONASS, named PZ-90, to the ITRF (International Terrestrial Reference Frame). The revised GLONASS datum is named PZ-90.02. It was implemented on September 20, 2007.

It doesn’t match ITRF05 exactly, but I understand their intent is to do so eventually. They publish the PZ-90.02 difference from ITRF05 as:

Delta X: -36cm
Delta Y: +8cm
Delta Z: +18cm
There is no rotation.

Lastly, the long-awaited news about GLONASS possibly migrating to CDMA (to be compatible with GPS and Galileo specs) was discussed. The decision seems final (except the final government stamp) that GLONASS will eventually offer a CDMA signal interoperable with GPS L1 (called L1CR) and GPS L5 (called L5R). Not much else to mention on this now because it’s years—even a decade—away from now, but good news for users nonetheless.

Galileo. There’s a lot to write about this, but also nothing to write. As users, we would benefit tremendously from Galileo. But it’s time to quit talking and start doing. That’s not to say they haven’t been doing; hundreds of millions of dollars are being spent developing Galileo, but the same discussions about the benefits are becoming stale.

The biggest, and possibly best, news is that the European Union is not considering the PPP (Private-Public Partnership) funding model any longer. Looks like it will be a publicly financed system, at least into initial operation.

To borrow a slogan from Nike: Just Do It.

NDGPS. I blogged quite a bit about this during the conference.

Not much post-ION conference information on NDGPS. I see that the invitation for public comment on NDGPS is now closed. Last I checked, there were only about 42 public comments. I read through most of them; about 25 percent were not relevant. There were some very good comments in support of NDGPS.

NDGPS is probably going to survive in one form or another. I think it’s likely that some stations will stay and some will go away. If that’s the case and the USCG picks up the 12 they say they will, then the reduction in coverage will be minimal. The other possibility is that once the purse-string folks understand the cost of shutting down a site, that may be a big enough deterrent that the DOT finds the budget dollars somewhere to keep them going.

Satellite-Based Augmentation Systems (SBAS)

WAAS. Finally, long-term WAAS geo configuration is settled. The two legacy WAAS geos stopped broadcasting a couple of months ago. Right after the ION conference, the WAAS ground software was upgraded to incorporate the new reference stations in Canada and Mexico. WAAS users in Southern California, Southern Texas, Maine and Minnesota should see improved performance. The FAA GNSS program manager, Leo Eldridge, also stated that they are considering adding a third WAAS geo at 125W longitude, but that would be 3-4 years down the road.

EGNOS. The European Space Agency says EGNOS is in Initial Operations Phase (IOP) and expects it to enter Long-term Operations Phase (Safety-of-life, Commercial Services) in a couple of years. EGNOS is usable now and there are three broadcasting GEO satellites. See my July 2007 column for details.

The ESA reports that EGNOS coverage will expand northward, and eventually into Africa.

MSAS. MSAS was declared operational on September 27, 2007. There are two GEO satellites identified as PRN 129 and PRN 137; if your receiver doesn’t recognize them, check with the manufacturer for a firmware update. Ground users should be able to benefit from MSAS in a broad area including Australia. Here is a coverage map:

Industry Developments

Javad GNSS. Ever the GNSS maverick, Dr. Javad Ashjaee came to an agreement with Topcon, and now both companies are free to compete in all markets as of January 2008. Ashjaee has plenty of experience competing in survey/construction, so I would expect to see his company introducing products to that market next year.

Septentrio. It’s not often that you encounter a new designer of high-performance GNSS receivers. This little-known Belgian company might prove to be a factor in the GNSS market. They’ve positioned themselves as an OEM supplier, much like Novatel, so you probably won’t see their name on a product that you use, but they may make the guts of a product you use. They just opened a U.S. office in Los Angeles, California, that is run by the guy (Chris Litton) whose father (James Litton) founded NavCom Technology, a competitor of sorts. Weird.

NavCom Technology . NavCom is a wholly owned subsidiary of John Deere Company that has been focused on providing precision agriculture solutions for their owner. Now, that may be changing. They’ve hired two salespeople to develop external sales to achieve “NavCom’s revenue and growth goals for GPS products and services in direct sales, government customers, system integrators, and OEMs,” according to their press release.

Some of NavCom’s key engineers developed the first Leica survey receivers while at Magnavox, so they have the technical capability. But creating a better mousetrap in the survey/construction market isn’t necessarily the name of the game. They’ve got to have a solid dealer network, and that isn’t easy.

Leica/Novatel. No big surprise here: Leica (Hexagon) bought Novatel for $390M ($50/share). Novatel has been Leica’s sole source of GNSS technology for several years. If you bought Novatel stock five years ago for a couple of bucks a share, you did well. Also, the Topcon/Sokkia acquisition is still waiting for Japanese government approval, and with Novatel being Sokkia’s source of supply for GNSS technology, Sokkia is in a really weird position.

GNSS Update,  Version 2.0

I, along with John Flick, co-authored a fairly in-depth piece on GNSS in the April 2006 issue of Geospatial Solutions. The basics of that article are still applicable, but here’s an update on GNSS events that have transpired since then — with a bit of speculation and guesstimation thrown in.

The most talked about GPS modernization subject since then is L2C.

There are now three IIR-M satellites in orbit that are L2C-capable. Most GPS receiver manufacturers have introduced “L2C-capable” receivers. Although the GPS Wing reports that no data is currently broadcast on L2C, the pilot carrier for L2C is available and useful by L2C-capable receivers. In fact, some experts say that the data on L2C is less important than the carrier. The reason is that with the complexity of semicodeless (legacy) L1/L2 receivers, a real signal loss of 3dB on L2 results in a net loss of 6dB. Using the L2C carrier, it’s a 1:1 ratio.

You can read an older (2001), yet still valid article written for GPS World on L2C. Ignore the dates, because they aren?t valid any longer. Also, ignore references to consumer L2C receivers. The viability of those was effectively nixed when Galileo decided not to use that frequency.

Code on L2C will add some marginal benefit, but that won’t be available for a while still. The GPS ground infrastructure is aged and wasn’t designed to handle L2C codes. Some of the infrastructure dates back to the 1970s. Next month, the GPS control segment will undergo a major upgrade as part of the Architecture Evolution Plan (AEP).

Still, the limiting factor for L2C users is the lack of satellites.

AEP Upgrade

The upgrade is a major step. But the GPS Wing says they’ve been preparing for more than a year for the transition. Some observers have voiced a sort of “the sky is falling” doom that GPS may stop working when they attempt the upgrade. I don’t buy that. I’ll worry about many other things before I worry about that. As my wife told me last weekend while we were watching the Blue Angels (U.S. Navy fighter aircraft demonstration team), “I’m glad those guys are on our side.”

One other note on the AEP upgrade. The current GPS control segment infrastructure is only able to accommodate 32 satellites. Next month’s scheduled launch would bring the current constellation to 32. Given that there will be four remaining IIR-M satellites to be launched after next month’s launch, but no way to accommodate them other than removing serviceable satellites from the constellation, the time for increasing capabilities is officially here. This AEP upgrade will expand that number to 60 and render this a non-issue for decades to come.

You can read more about the AEP upgrade here

Satellite Launches

Right now, there are five remaining Block IIR-M satellites to be launched. The last one was launched in late 2006. The good news is that the GPS Wing has stated one of their top priorities is to launch the remaining five. The next one is scheduled to launch next month. According to an interview by GPS World Editor-in-Chief Alan Cameron with then GPS Wing Commander, Col. Wesley Ballenger, Jr. back in March 2007, the schedule looks like this:

September 2007
December 2007
March 2008
June 2008
September 2008

As in the past, the schedule could slide due to various reasons (resources and/or technical primarily), but all indicators seem to point that the September launch is a “go” — except that it has now reportedly moved slightly to the left, to October 17. Politically, this launch is an important one because, traditionally, it goes up prior to or during the Institute of Navigation (ION) GNSS conference where the GPS Wing makes the “successful launch” announcement — except that won’t quite happen this time around

For precision GPS users, does it really matter what the launch motivation is — as long as they keep doing it? I don’t think so. The bottom line is that more is better.

Interesting Twist

The GPS Wing has said their desire is to launch the first Block IIF satellite (L2C, L5) before all the IIR-Ms are launched. The reason is to be able to take time to flush out any bugs, especially in a new satellite model, that may occur.

I have no doubt they’ve thought it through and it’s a solid strategy. But it sure complicates the scheduling and really lowers the confidence level that the IIR-M launch schedule will stick. Here’s why:

The AEP upgrade mentioned above is required in order to control the Block IIFs. But, my understanding from the GPS Wing media conference call last week is that another software “update” (beyond next month’s AEP upgrade) is required to the control segment before the first Block IIF can be launched. According to the GPS Wing, that “update” will occur Spring/Summer 2008 and therefore push back the estimated IIF launch date of March-May 2008 to Summer-Fall 2008. One would think this would impact the IIR-M launch schedule.

Furthermore, the Block IIF program has had its share of technical issues. Boeing is scheduled to deliver the first Block IIF in mid-December 2007 but that’s many months too optimistic. Rumor has it that it could be well into 2008 before the Block IIF is delivered. Then with testing and integration, we could be well into 2009 before it takes flight. It’s not hard to doubt the IIR-M launch schedule as laid out above.

Testing L5 on IIR-M

In April 2007, Lockheed was awarded a $6 million contract to develop and demonstrate a payload that will temporarily transmit L5 (1176Mhz) from a Block IIR-M satellite. L5 was originally planned for Block IIF satellites and it’s not likely this will change. All indicators seem to agree that this will be a non-operational, temporary test on one IIR-M to test L5 before Block IIFs are launched.

Not a lot of info on this, but I expect a new press release shortly.

More is Better

As high-precision GPS users, we’re on the leading edge of GPS technology. We push the technology hard and therefore we feel the bumps in the road before anyone else. The biggest bump now is the lack of satellite observables. I can’t count the number of people who have emailed me about the “down-time” during the day due to the lack of GPS observables — even in the wide-open plains of mid-western America, not to mention the beautiful, foliage-laden, topographically-broken northeastern US.

The bandaid for high-precision GPS users, to this point, has been to rely on the Russian system (GLONASS). Whereas three years ago, there were many high-precision, GPS-only receivers on the market, now they are the minority. Almost every high-precision GPS manufacturer offers a GPS/GLONASS receiver. But adding GLONASS to the mix isn’t enough. I’ve used GPS/GLONASS receivers. Sometimes GLONASS helps, sometimes it doesn’t. There aren’t enough GLONASS satellites to help all the time. But I generally advise high-precision users to spring the extra $$ for the GLONASS option because there’s not another choice if you want to add observables.

There’s not enough space here to update you on GLONASS, Galileo, and other GPS modernization initiatives so look for those in the coming months. Also, the ION GNSS conference is next month and I’ll be sure to give you an update on what I hear. There should be some good stuff coming from that conference.

NAVCEN and the CGSIC

I thought this would be a timely subject, since I’m heading off for two days of CGSIC/NAVCEN presentations before the ION GNSS 2007 conference starts on September 25. I’ll also be staying for the conference, and reporting back to you on what I hear there.

NAVCEN is an acronym for the U.S. Coast Guard Navigation Center. Its mission, according to its website, is to “provide cutting edge services for safe, secure, and efficient maritime transportation.”

CGSIC (est. 1987) is an acronym for the Civil GPS Service Interface Committee. It is the forum for the civil GPS community to communicate with GPS authorities, and vice versa. According to the CGSIC website, the committee “was established and chartered to identify civil GPS user needs in support of the Department of Transportation’s program to exchange information concerning GPS with the civil user community as part of the GPS ‘outreach’ program.”

The NAVCEN and CGSIC work hand in hand in facilitating communications for the civil GPS community; NAVCEN coordinates and manages the CGSIC. The NAVCEN site is one that you should have bookmarked in your web browser; there’s a lot of good information there. Here are some examples:

1. Notice Advisory to NAVSTAR Users (NANU) report: you can sign up for a daily e-mail that reports on the day-to-day status of the GPS constellation, or you can view the GPS constellation online. This is very helpful way to keep track of satellite outages that may affect your GPS field operations. For example, if a particular set of satellites is important to keep the PDOP low in your area, this is a good tool to let you know if one of those satellites is having a problem.

2. GPS Status Message (TIS-PF-NISWS) — This is daily GPS status report. If you subscribe to this mailing list, you will be sent an e-mail within 60 minutes of notification by the U.S. Air Force of a change to the constellation.

3. View and download the daily GPS almanac. (Both YUMA and SEM almanac formats — which most GPS mission planning software packages can handle — are available.)

4. View a list of DGPS and NDGPS sites broadcasting corrections. If you’re not sure you will be in range of a DGPS or NDGPS broadcasting station, this site provides details on each broadcasting station, including the precise location of the station, signal strength, expected coverage area and transmitting frequency.

The CGSIC coordinates some very informative meetings with very good information. Its membership is made up of U.S. and international private, government and industry user groups. The committee membership is free and open to anyone who is interested.

CGSIC meets at least once per year in conjunction with ION GNSS, which is usually held in September. However, there are subcommittee meetings throughout the year. There are four subcommittees:

• International Information Subcommittee.
• U.S. States and Local Government Subcommittee.
• Survey, Mapping and Geosciences Subcommittee.
• Timing Subcommittee.

The International Information Subcommittee last met in May 2007 in Geneva, Switzerland. Members are free to attend, but if you can’t, then you can download all of the presentations for a quick update. Going back and viewing previous years’ agendas and presentations is very informative.

The U.S. States and Localities Subcommittee last met in June 2007 in Bend, Oregon. I attended this meeting. There was good discussion on NDGPS, NGS initiatives and Network RTK. The Subcommittee also met in June 2007 in Minnesota. Notice the central theme of both meetings: NDGPS (but that’s another story).

The Survey, Mapping and Geosciences Subcommittee is a relatively new one. Not sure when they’ve last met, but I’ll get up to speed on that one at the CGSIC meeting. As for the Timing Subcommittee, I don’t stay current with that because it’s outside of the survey/mapping market.

Next week’s annual ION GNSS CGSIC meeting looks to be a good one: two days packed with all that a GPS connoisseur like me can handle. Day One is high-level information — policy stuff as well as program status reports on GPS, L1C, WAAS/LAAS and NDGPS.

Day Two is tough for me, because there are concurrent sessions by the three Subcommittees I follow:

• GLONASS, Galileo, EGNOS, QZSS/MSAS, GBAS/GRAS, Beidou/Compass from the International Subcommittee.
• HA-NDGPS, NDGPS and USCG DGPS from the U.S. States Subcommittee.
• CORS/OPUS, various NGS initiatives, RTK Networks and Space weather from the Surveying, Mapping and Geosciences Subcommittee.

You can find a detailed look next week’s CGSIC agenda here.

This year, GPS World is doing something a little different, and I think you’ll like it. My e-newsletter colleagues and I will be your eyes and ears during the CGSIC and ION GNSS meetings; “We’re Bringing ION to you!” is the theme. We’ll be writing daily reports on subjects we think may interest you, and the website will be updated twice daily during the week.

If there’s something in particular you want me to check out while at the conference, fire off an e-mail to [email protected], and I’ll do my best to cover it.

EGNOS Embraces Ground Users The European Geostationary Navigation Overlay Service (EGNOS) is Europe’s version of the U.S. Wide Area Augmentation System (WAAS) with essentially the same mission. It offers GPS users in Europe more accurate and reliably GPS positioning. Like WAAS, EGNOS focuses on improving the integrity and accuracy of autonomous GPS positioning primarily by modeling refraction caused by the ionosphere. Also, EGNOS was designed to be compatible with WAAS so your WAAS-enabled receiver will work with EGNOS just fine. The system is similar to WAAS in that it’s an augmentation to GPS. It primarily consists of a network of ground reference stations (RIMS) and three broadcasting satellites. This is done via the network of ground stations spread out over Europe as follows:

RIMS = Ranging and Integrity Monitoring Stations MCC = Master Control Stations NLES = Navigation Land Earth Station PAFC = Performance and Assessment Check-out Platform ASQF = Application Specific Qualification Facility In a quick sentence, the MCCs process the data collected by the RIMSs and the NLESs send the processed data to the three geostationary satellites that rebroadcast to the users. Got that? As I mentioned, there are currently three EGNOS broadcasting satellites: -PRN 120 (Inmarsat 3 F2) located at 15.5 West Longitude. -PRN 126 (Inmarsat 3 F5) located at 25.0 East Longitude. -PRN 124 (Artemis) located at 21.5 East Longitude. PRN 120 and PRN 126 are to be used by the general public. PRN 124 is available to the public but designed for use by companies to “perform various tests on the system” according to the European Space Agency (ESA). Generally speaking, the user needs line-of-sight visibility to either PRN 120 or PRN 126 in order to use EGNOS (there are a couple of exceptions I’ll mention later). There is a nice online tool at http://www.lyngsat.com you can use to determine approximately how far above the horizon PRN 120 and PRN 126 are in your area: PRN 120 – http://www.lyngsat.com/tracker/inmar3f2.html PRN 126 – http://www.lyngsat.com/tracker/inmar3f5.html One major exception to the line-of-sight rule is something that significantly differentiates EGNOS from WAAS. The line-of-sight rule has been the major inhibitor for WAAS ground users. Some companies have used innovative methods to overcome this limitation, but EGNOS has taken it to another level. EGNOS has embraced the ground users — something that WAAS has done poorly. To address the needs of the ground users (engineering and scientific community), EGNOS developed Signal-in-Space through Internet (SISNeT). SISNeT is a method of distributing EGNOS corrections over the Internet instead of requiring line-of-sight visibility to PRN 120 or PRN 126. What a great idea! WAAS really missed the boat on this one. All users need is a mobile phone with a data plan (like network RTK) to connect to their GPS receiver and they don’t have to worry about EGNOS satellite visibility. Granted, if you’re using a consumer-grade receiver, this doesn’t make much sense. But if you’re using high performance receivers (1-2 meters) for mapping and you’re in an area where you won’t have consistent visibility to PRN 120 or PRN 126, this makes a lot of sense. Like WAAS, EGNOS accuracy claims (1-2 meters) are a little ambiguous and generally on the conservative side. Like WAAS, you need to be working inside the EGNOS IGP (Ionospheric Grid Point) area to take full advantage of EGNOS accuracy. Note that some receivers are designed to exploit EGNOS outside of the IGP area with some accuracy degradation, but your average consumer GPS unit won’t do this. The following graphic defines that area:

A year ago, the ESA declared that EGNOS was declared “fully-deployed” for “non-safety of life” applications such as mapping. This is the so-called Initial Operations phase of EGNOS. Safety-of-life applications using EGNOS such as aviation navigation aren’t approved yet, but the news seems to be good. On June 28, 2007, the African aviation safety agency (ASECNA) signed up to cooperate with ESA to improve aviation traffic safety over the African continent. The ESA has done a really good job of publishing detailed information on EGNOS. There is even a website referred to as EGNOS for Professionals that gets as technical as most people would like. EGNOS web site – http://www.esa.int/esaNA/egnos.html EGNOS For Professionals web site – http://www.egnos-pro.esa.int/ EGNOS SISNeT web site – http://www.egnos-pro.esa.int/sisnet/index.html Lastly, I’ll leave you with some data collected last month. It’s always good to get a real field perspective. Through my grapevine, I was able to obtain data collected in Italy (June 2007) using EGNOS corrections. Enjoy. Here is the graphic plot:

Here is the tabular data:

WAAS Up?

It’s been about a year since I’ve touched on WAAS (Wide Area Augmentation System) with any depth, and a lot of things are happening on that front so I’d thought I’d give an update. Also, look for a column on EGNOS (Europe’s version of WAAS) in the next month or two.

WAAS is finally going to settle down, in terms of the WAAS broadcasting satellites; the final one is scheduled to become operational (for aviation users) in mid-July. Although it should never have been a headache for ground users like us (many of us have been using the satellite for mapping for more than a year), it was — mainly because several manufacturers of mapping receivers insisted on allowing their receivers to use only WAAS in aviation mode, which didn’t make any sense.

Anyway, two significant events will happen next month. One is mentioned above, which means that users in the eastern/northeastern US and eastern Canada who are using mapping receivers that require WAAS to be operational for aviation users will now be able to use WAAS more reliably.

The other event happening next month is that the two legacy WAAS broadcasting satellites, POR (PRN 122) and AOR-W (PRN 134), will stop broadcasting WAAS information. This has been the FAA’s plan all along. It will leave two WAAS broadcasting satellites (PRN 135 and PRN 138) that provide dual coverage throughout the US. Alas, WAAS satellite visibility will never be as good as it was for northeastern US and northeastern Canadian users when AOR-W was at 54W longitude.

After the two legacy WAAS satellites stop broadcasting, the coverage footprint will look like this:

This will put the nearly 18-month WAAS satellite reconfiguration confusion to bed.

Another major milestone for WAAS later this summer is an upgrade that will add four new reference stations in Canada and five in Mexico. Also, new reference stations in Alaska will be added to the Iono grid.

What this means is that WAAS coverage will expand to the north (Canada) and south (Mexico). Users will also see improved performance on the fringes of the current WAAS service area (southern Texas, southern California, New England states, etc.).

Following is a map of the Iono Grid Points (IGPs) for the current WAAS service area:

And here’s a map of the IGPs for the expanded WAAS service area:

WAAS Accuracy

Even though the expanded IGPs have yet to be implemented, WAAS accuracy is impressive. The National Satellite Test Bed (NSTB) produces a WAAS Performance Report on a quarterly basis. Each GPS receiver collects about 7,000,000 each quarter, and the NSTB compiles and publishes the test results.

Following are the results of Q1 2007:

For a system that was originally specified to provide 7-meter accuracy, the performance is impressive. At the 95% confidence level, horizontal accuracy for all test sites across the CONUS and some in Alaska are all under a meter. Also, remember that these figures will improve with the addition of the new reference stations later this summer.

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.

Getting Personal, Now

Ok, this column is supposed to be about high-precision GNSS, right? Well, who would have ever thought I’d be inclined to write about consumer GPS receivers? Certainly not me. Sometimes, I even speak rather condescendingly about those “Wal-Mart GPS units” because they seem to be mis-used so often in the survey/construction business.

But with the explosive growth of Personal Navigation Devices (PNDs) and being the GPS technology-aholic I am, I had to give some of these a try. Surprisingly, I became addicted to them in short order. Mind you, I already have an in-dash GPS navigation system in my car so this isn’t a new concept to me. So why the big fuss?

First of all, let’s define a PND so everyone’s on the same page.

The newer PNDs are roughly the size of a slice of French bread with a 3”-4” LCD touch screen. Its primary function is to guide you from Point A to Point B by providing you turn-by-turn instructions on the map screen and via voice instructions. Seriously — it talks to you. It typically comes with a street/address map database of the region where you bought it such as North America, Europe, etc. It runs on batteries or vehicle power and comes with some sort of windshield or dashboard mount.

Whereas legacy PNDs were bulky and ran a short time on batteries and were really designed to stay mounted in your car, the newer PNDs are slim. They are designed to be truly portable with features that support “grab and go” functionality like ruggedness and extended battery operations.

The PND did its job of getting me to where I needed to go. But the great part about it was that when I needed to alter plans, like a last-minute dinner meeting, it was perfect. With my old Mapquest method, I would have scrambled to find directions.

But, secondly, perhaps what surprised me most and what prompted me to focus this month’s column on PNDs is the response I’ve been receiving from people who see me using the PND. I’m not talking about soccer Mom’s or Joe consumer. I’m talking about architects, construction superintendents, engineers: professional types. I’ve been on project sites where these types of people see me using the PND and they start asking questions.

Most see it as a really productive business tool because they spend a lot of time traveling from one project site to another and aren’t necessarily familiar with the local hotels, restaurants, reprographic vendors, construction material vendors, and so on.

Some have even exclaimed they can’t believe there’s not a monthly subscription fee. There’s not. Although after a couple of years of ownership, you’d probably want to purchase an updated map database.

So the pessimist in me asked what happens if I become too dependent on the thing. After three days in San Francisco, I’d used the PND exclusively to navigate my way around the different suburbs. At the end of my trip, I dialed up the rental car location on the PND and let her take me home. Sure enough, about 10 min. from the airport, the screen went blank. No warning, no nothing. Dead battery. After a few seconds of “uh oh, what am I’m going to do now?” I remember I packed the car charger. I pulled over, plugged it in and off I went. But, it made me think about what I would have done otherwise. My conclusion was that, worst case, I pull over and ask for directions.

The attractive feature of the “grab and go” functionality with new generation PNDs is that they aren’t tied to a specific vehicle. I found myself throwing it on the seat of rental cars and not using the windshield mount at all. To me, there was not enough value in hooking it up all that mounting hardware. I’d rather stuff it in my laptop bag and pull it out when I need it. I can imagine a small survey outfit having one unit in the office that folks check out for the day no matter which rig they are taking in the field.

Another attractive feature for survey/construction professionals is that some of the new generation PNDs allow you to load topo maps in addition to having turn-by-turn directions, points of interest, etc.

Time is money and it doesn’t take an MBA to figure out that if the PND saves time getting folks to each project site faster, it’s a no brainer at the ~$500 price tag.

L1 RTK follow-up

I promised I wouldn’t visit this subject again until products starting hitting the streets. It’s starting to happen. read more >>

Momentum is a powerful phenomenon. When thought of in terms of a moving object, its mass and velocity can be measured. In other respects, it’s immeasurable. Feelings of confidence, trust, and faith can’t be hard-coded — but can make the difference between winning and losing. Whether in the context of a football game, the stock market, or a presidential election, positive momentum builds confidence, and confidence feeds the momentum. The Big Mo.

In 2006, GPS constellation health has declined, but a well-timed presentation by Brad Parkinson at the ION GNSS 2006 conference has injected renewed enthusiasm into the GPS program. Parkinson’s call for a 30-plus satellite constellation may constitute a boon for GPS survey/mapping users in 2007. More satellite signals and healthier satellites mean increased productivity. While 2006 saw two IIR-M satellite launches, look for double that in 2007. Even if new launches don’t improve the PDOP spikes, we’ll have more reliable hardware in orbit. The Big Mo is rolling.

The short-term benefit of the IIR-M launches is a healthier constellation. Another, longer-term benefit comes from the addition of the second civil frequency. L2C may bring some value to L1/L2 users in 2007, but with only eight IIR-Ms even potentially operational by year’s end (assuming five are launched in 2007), plus the requirement to have an L2C-capable reference station, the bennies will be limited.

GLONASS is still a crapshoot and may likely continue that way into 2007, but it doesn’t matter because its value is augmenting GPS. Up until a few months ago, it had The Big Mo on its side. Then GLONASS headed south in a hurry in September, when nearly a half dozen satellites were declared unusable “due to maintenance.” This continued for 30-plus days. The good news is that the Russians are launching GLONASS satellites at a pretty good clip, and GPS/GLONASS users don’t need a full GLONASS constellation for it to be useful. Three more are scheduled to launch this month and six are scheduled for launch in 2007.

Even if only half of those become operational, GPS/GLONASS users will feel the love in 2007. Worldwide GLONASS usage will increase significantly in 2007 now that all major survey instrument manufacturers have introduced and will begin rolling out their GPS/GLONASS-capable products. The Big Mo will return.

Galileo won’t do anything for the survey/mapping user in 2007, but that doesn’t mean you don’t keep tabs on it. Galileo has the potential to deliver Huge Mo for survey/mapping — just not in 2007. The business model will continue to receive scrutiny, and the discussion of military use will spin things around a bit, but development and testing will continue. The key news to look for in 2007 will be any significant delays. 2008 should be a Big Mo year for Galileo if the program can stay on target, and if tight GPS interoperability is realized.

Satellite-based augmentation systems (SBASs) like the United States’ WAAS, Europe’s EGNOS, Japan’s MSAS, and India’s GAGAN also have Big Mo on their side. Virtually every GPS receiver shipped today is SBAS-capable. WAAS will finally stabilize with respect to the communication satellite adjustments made in 2006, and EGNOS should be declared operational. The worldwide SBAS user base will continue to show strong double-digit if not triple-digit growth.

NDGPS (National Differential GPS), another GPS augmentation system, will encounter the most significant crossroad in its decade-long history of service in 2007. Lack of support threatens the program’s existence. The worst-case scenario is that NDGPS will shut down as early as October 2007, leaving the U.S. Coast Guard to operate only 40 or so maritime DGPS broadcast stations along coastlines and major waterways. Big Mo left some time ago, and No Mo has moved in.

Reshaping the Marketplace. The most interesting GPS survey/mapping innovation for 2007?

L1 RTK.

While not the most innovative technology because it’s been possible for many years, it holds great interest because of its potential to reshape the survey/mapping marketplace. It will fill a gap between L1 static systems and high-end L1/L2 RTK systems. Those L1 static users who could not overcome the financial jump to an L1/L2 RTK system costing several tens of thousands of dollars will now have the productivity of RTK within reach.

Why now, and not five years ago? Follow the money to find the answer. L1/L2 RTK systems still run in the US$25-45,000 range. Competition among high-end GPS manufacturers is heating up, so they’re looking for opportunity. L1 RTK systems will be half that price — maybe even one third. Yes, baseline lengths will be limited to a few kilometers, and initialization times will be measured in terms of minutes rather than seconds, but the accuracy will be the just as good as high-end L1/L2 RTK systems.

Satellite constellation health will be the wildcard for L1 RTK. 2006 was not a good year for the GPS constellation. With L1 RTK and a weak constellation, productivity would be an issue, especially if you aren’t operating in a really clear open-sky environment. However, the good news is that it seems GPS Wing of the U.S. Air Force is in giddy-up mode again. If they share Parkinson’s vision of a 30-plus satellite constellation, L1 RTK could end up being a very productive tool — with Big Mo on its side.

Eric Gakstatter is editor of GPS World’s Survey & Construction e-newsletter. Free subscription available.

More DIRECTIONS 2007

Every December GPS World invites experts to share insights on what the new year holds. Here are additional views in the Directions 2007 feature:

SYSTEM DESIGN & TEST
Opportunity, Innovation — and Choice
By Charles F. Trimble and F. Michael Swiek

MILITARY & GOVERNMENT
Through a Glass, Darkly
By John T. Kelly

AVIONICS & TRANSPORTATION
Modernizing, Expanding GNSS Use
By Bill Thompson

LOCATION-BASED SERVICES
As Navigation Goes, So Goes LBS
By Mike Sheldrick