A GNSS industry representative stationed in Shanghai, China sent this message recently to a U.S. colleague: “Latest unofficial news said that the Compass Interface Control Document (ICD) will be released on 27th this month, and will be available on the internet on 28th.”
Such rumors have floated before, in late 2010, and again in late 2011. As the U.S. colleague noted in passing on this light intelligence, “There was a lot of hand-wringing at ICG [Seventh Meeting of the International Committee on Global Navigation Satellite Systems (ICG), organized by the Government of China, Beijing, China, 5 – 9 November 2012] around the Chinese keeping their promise for 2012 release of the ICD. Maybe they are just going to slip it under the wire.”
In an October, 2011 newsletter column, the GPS World editor wrote: “The long-awaited signal interface control document (ICD) for China’s growing GNSS will appear this month, according to representatives of the system who spoke in a “Compass: Progress, Status, and Future Outlook” workshop as part of ION GNSS and the CGSIC meetings in Portland in September [2011].
“The ICD has been rumored to be available previously to receiver manufacturers within China, creating some disgruntlement among companies outside the country. One of the workshop panelists affirmed that GPS/Compass chips and receivers are being actively developed by many Chinese manufacturers and research institutes.”
The Research and Innovative Technology Administration (RITA) seeks an experienced Electronics Engineer interested in joining the Office of Positioning, Navigation, and Timing (PNT). RITA coordinates the U.S. Department of Transportation’s (DOT) research programs and is charged with advancing rigorous analysis and the deployment of cross-cutting technologies to improve our Nation’s transportation system. RITA serves as the lead Administration representing DOT on PNT matters, including development of departmental positions on PNT and spectrum policy and protection, and is responsible for representing and supporting the civil Departments and Agencies in PNT systems analysis and coordination, including PNT requirements and architectural development.
In this challenging role, you will serve as the program manager for the inland (terrestrial) segment of the Nationwide Differential Global Positioning System (NDGPS) Program and serve as the lead for radio frequency spectrum management and analysis functions in support of DOT’s technical requirements and policy development.
As the NDGPS Program Manager, you will be responsible for the technical, cost and schedule performance of the NDGPS, as managed currently through the United States Coast Guard under a Memorandum of Agreement, and serve as the chair of the NDGPS Policy and Implementation Team.
You also will lead radio frequency spectrum management and analysis tasks in close coordination with other DOT Operating Administrations and the National Telecommunications and Information Administration (NTIA). You will provide expert advice specifically on issues of harmful radio frequency interference and operational degradation to DOT operations and planned operations, and serve as DOT’s representative to the Interdepartmental Radio Advisory Committee (IRAC).
If you or someone you know has the experience and a demonstrable record of proven results, I encourage you or them to apply to this Washington, D.C.-based position. We are looking for a diverse pool of qualified candidates
The announcement is posted to the Public and to Merit Promotion eligible applicants on www.usajobs.opm.gov. Please know that Merit Promotion announcements are the vehicle through which Federal employees generally apply for Federal positions.
Here is the accuracy and estimation game played by 208 guests at GPS World’s Leadership Dinner in Nashville, Tennessee, on Thursday evening, September 20. Take a gander at the rules that follow, and then try your skill at the nine questions.
To play fair, do not use Google or any other research, reference, or resource. Dinner guests were honor-bound not to employ their smartphones — just their smarts. You are, too.
The first six questions had known answers (at least to the gamesmasters) at the time of the dinner. The final three peered into the future, as of that evening. Two of them have since been determined. Once the Galileo question is settled, the What Do You Know Grand Winners — 10 individuals who sat and gamed together among the 21 competing tables — will be announced, and suitable tchotchkes distributed.
A special division for online contestants has been established; send your answers to [email protected]. Any entries that are too suspiciously close to the true answers will be disqualified for use of unauthorized resources.
The accounting and awarding — and all the answers — will appear on the Wide Awake Blog in the very near future. Do not touch that dial.
Game Rules
1. What Do You Know? What’s Your CEP? consists of nine quantitative questions. Answer each question as best you can — without the aid of outside sources! Then give your error range: an upper bound and a lower bound.
Answers will be graded on how close they are to the true answer, the size of the error range given, and whether that error range encompasses the true answer. The smaller your error range, the higher your potential score — but if the true answer falls outside your error range, you score zero for that question.
2. The second and third rules pertained to “play by tables” at the dinner, and are irrelevant and thus omitted here.
4. A final trifecta of three questions asks you to predict events in the future. After turning in your answers to these questions, game play concludes for the evening. A final Grand Prize to the winning table will be awarded after the last event.
A more detailed mathematical explanation of the scoring process is available at the scorer’s table, should you wish to see it.
And now, are you ready to play . . . .
What Do You Know??!!??!! What’s Your CEP??!!??
1. Estimate the distance in kilometers from Shanghai, China, to Nashville, Tennessee, along a Great Circle global route, and from that derive the number of Delta II booster rockets (used to launch GPS satellites) laid end-to-end that would cover that distance.
Upper bound ______________
Absolute answer _________
Lower bound ______________
2. Give the total area, in either square inches or square centimeters (specify which you are giving) of a rather substantial hat worn by Kate Middleton, Duchess of Cambridge, to a friend’s wedding in July of this year.
Kate Middleton
That hat!
Upper bound ______________
Absolute answer __________
Lower bound ______________
3. Peg the number of total orbiting and operating GNSS satellites, including SBAS, as of September 20, 2012.
Upper bound ______________
Absolute answer _____________
Lower bound ______________
4. Jack Daniel’s, a sour mash whiskey made in Lynchburg, Tennessee and the best-selling whiskey in the world, is known for its square bottles and black label. How many shots of whiskey does a white-oak barrel of Jack Daniel’s contain?
Jack Daniel’s barrel in the Hermitage Hotel, Nashville
Upper bound ______________
Absolute answer _____________
Lower bound ______________
5. How many of Richard Langley’s “Innovation” columns have appeared in GPS World magazine?
Upper bound ______________
Absolute answer _____________
Lower bound ______________
6. In his memoirs, Tony Blair mentions that, when he first met Queen Elizabeth II as Prime Minister of the UK, the Queen put him in his place by telling him, “You are my tenth prime minister. The first was Winston. That was before you were born.”
In a similar vein, how many individuals have served as Prime Minister (official, not acting or deputy) of Japan from the beginning of the Shōwa era under Emperor Hirohito in 1926 until today? (Note: This is the count of individual persons. A single person serving as Prime Minister several times, such as the postwar Prime Minister Shigeru Yoshida, counts only once.)
Upper bound ______________
Absolute answer _____________
Lower bound ______________
Final Trifecta
7. Predict the number of days that will elapse between the day of the combined launch of the Galileo IOV-3 and IOV-4 satellites and the day when the first satellite of that pair is declared operational. Dates are defined based on UTC. For example, if the launch should take place on the currently scheduled date of October 10, then October 11 would be 1 day, October 31 would be 21 days, and so on. If the launch occurs on a different date, we start counting from there.
Upper bound ______________
Absolute answer _____________
Lower bound ______________
8. Predict the number of U.S. states, out of 50, that go blue in the Presidential election on November 6, 2012 — that is, their electoral votes go to President Obama’s Democratic Party ticket.
Upper bound ______________
Absolute answer _____________
Lower bound ______________
9. Predict the total number of combined points scored in all three NFL football games to be played on Thanksgiving, November 22: Houston Texans vs. Detroit Lions, Dallas Cowboys vs. Washington Redskins, New England Patriots vs. New York Jets.
Some of you have been asking questions, and while it is generally our business to provide answers, in this case I simply show these questions back to you, for instructive purposes.
They come from the 2012 State of the Industry Survey, reported in the September issue. In that survey, we posed one question whose results were not reflected in that report. It was “What questions do you think it would be interesting and illuminating to ask in the 2013 State of the Industry Survey?”
Herewith those questioning answers — er, those answering questions:
What effect will the aging satellite system have, and what are you doing to plan for an alternative?
Which industry is the most powerful to impose its technology standard? For example, it seems that any technology not compatible with mobiles or tablets is not alive anymore.
What is the estimated financial impact that GNSS have, and how would it affect your life if we didn’t have them?
With the technology of the GNSS equipment constantly improving, how important is it that the end user be a licensed professional?
The prices of Chinese products — are they directly affecting your sales, or are your customers taking these low prices as a starting point for negotiation?
Should precision and accuracy be government regulated?
What will be the next game changer for positioning? Will it be all encompassing like GPS? Or will there be multiple positioning options depending on your need? (indoors, urban corridor, dense veg., accuracy needs, and so on).
How can the cost of modern survey equipment be subsidized for developing countries?
How long will multi-chip solutions maintain dominance compared to separated solutions where technological development and cost reduction is even faster?
What alternative tracking methodology will replace GPS/GNSS as the most common?
What are the cost and practical barriers to innovating new consumer and business products? Are you willing to throw away existing products to distribute new products?
How accurate is good enough?
Is replacement of staff with technical skills a concern?
Should the recent demonstration of commandeer-via-spoofing have been so widely publicized — or should that development have been classified?
Have your customers expressed concern about GPS tracking and their privacy?
What will it take to get RTK GNSS receiver manufacturers to standardize on one correction data format? What portion of revenues is invested in GNSS-related research and development at your company?
What is the status of the National PNT Architecture jointly developed by the US DoD and DOT? Is it viable, or is it dead?
The FCC director was on drugs the day they granted LightSquared bandwith — true or false?
What would be the effect of a 1-hour, 1-day, or 1-week disruption in GPS be on your product? What is your backup system?
What will be the long-term consequences of the CBOC patent issue? [Note that while a story on this page give a short-term answer, long-term consequences of intellectual property concepts are far from settled. — Ed.]
Is there still room for a LightSquared type technology in the current broadband and spectrum governance environment?
What kind of disaster will be required to get the U.S. government off the dime on an uncorrelated-failure alternative PNT system?
Are commercial manufacturers considering offering more flexibility in their receiver designs (open-source GNSS). Open hardware is an interesting trend.
What’s next after GPS III?
Will the COMPASS system gain general acceptance in 2013-2014?
Tell us more about the future.
[That last was my favorite question, one after my own heart. For any other questions you may have, or any answers for that matter, or if you have even a clue, please write to me at [email protected]. I’m listening. — Ed.]
In this column, I normally write about satellites, signals, and space (as in outer), and the policies or controversies pertaining to those entities. This week we are headed indoors. Inner space, where GNSS has difficulties going, but must go, somehow, to prove itself commercially and governmentally. To do so, it needs powerful friends.
The most rigorous indoor location testing to date got underway two weeks ago in the San Francisco Bay Area, in trials organized by a Federal Communication Commission’s (FCC) advisory committee, the Communications Security, Reliability and Interoperability Council (CSRIC). The tests seek to lay the groundwork for future FCC rulings on indoor location requirements, to which wireless carriers must adhere. The trials run through December 31, in dense urban, urban, suburban, and rural test blocks around the Bay.
For the sake of the GPS/GNSS industry and community, whatever technology solution emerges from these trials as the favorite, GPS/GNSS had better prove itself as a part of it, not only to gain a foothold in indoor markets and applications, but to preserve its standing in outdoor environments. Other positioning technologies have sprouted up like mushrooms, filling in vacant micro-niches. The indoor environment as a whole is just that, an environment, not a niche, and where it goes — taking the money with it — outdoor may likely follow. Wi-Fi, for example, is gaining installment base by leaps and bounds, and probably currently supplies the best unaided indoor location — where it is installed.
“Retailers are desperate for more customer data, this [indoor location data] is golden,” says Janice Partyka, GPS World’s contributing editor for wireless. “They probably won’t wait for the requirements or for the wireless carriers to push out the solution. Some venues like airports can track you now. This time around, commercial uses will precede E911.”
Although the need for accuracy is arguably greater indoors, so too are the difficulties — and the costs. At stake is getting room-level and floor-level location accuracy from a mobile 911 call to emergency responders during the Golden Hour, a term used in heart-attack, stroke, and trauma situations, but which applies equally to fires, violent crimes, and virtually by definition to any sort of emergency. Responders need to know “which side of the wall” he/she/it is on, and which floor — even before they enter the building.
In the floor-level or vertical component of the location coordinates resides one of the key challenges. The vertical or Z-coordinate in a GPS/GNSS solution has always had the lowest degree of accuracy. To be sure, the barriers imposed by steel, glass, and concrete, as well as the confusion generated by multipath in dense environments, apply just as much to the X- and Y-axes, but getting to Z (since getting from floor to floor in case a mistake is made would be most time-consuming) may constitute the largest challenge.
The FCC hosted a workshop in Washington D.C. on October 24 in preparation for the tests. The workshop introduced public-safety officials’ expectations for indoor coverage, test mechanics, the technologies under test, and more. CSRIC will draft a report for the FCC based on the test results by March 2013.
The Candidates, Please. Four companies are actively participating in the CSRIC tests, submitting their diverse indoor solutions for rigorous and repeatable performance proof: Boeing, NextNav, Polaris Wireless, and Qualcomm.
The CSRIC test bed discussions started in 2010 with seven potential technologies for Stage 1:
Polaris Wireless (RF fingerprinting)
Qualcomm (assisted-GPS/AFLT/cell ID)
NextNav (Wide-Area Positioning System (WAPS) of GPS-like terrestrial beacons, described here.)
Boeing (low-Earth orbit Iridium satellites; because much closer to Earth than GPS, hence 30-dB penetration margin; a range of Iridium solutions, some of them in combination with GPS
CSR (AGPS/WiFi/MEMS)
TruePosition (UTDOA)
CommScope (DAS proximity).
The latter three have since dropped out of the testing for reasons not stated.
Polaris Wireless is the only cellular-network-based location technology provider in the tests, as all other network-based location technology providers withdrew from participation in the CSRIC trials. The trial includes Polaris Wireless’ Wireless Location Signatures (WLS), a software-based radio-frequency (RF) pattern-matching approach that requires no changes to the wireless device or the wireless service provider’s base stations. The June issue of GPS World carried an article on this technology; see “Location by Database.”
Norman Shaw, Polaris Wireless executive director of government affairs and business development, serves as co-chairman of CSRIC’s efforts on improving indoor location technology. “RF does funny things. But there are cultural issues as well. It’s natural for us to expect technology to get us all the way to the goal line. However, we often overlook the challenges. Can we deliver Z-location? And can we do it in an actionable way for the emergency responder? That person needs to know, not that the emergency is 185 meters above the ground, but the number of the floor. For this and for other reasons, you need to marry different technologies.”
“This test is a great start,” Shaw concludes. “But this test bed will need to be maintained to continue testing and to test future technologies. Additionally, a second test bed will be needed in a denser, older city, probably East Coast; perhaps Chicago or New York. We should all be aware that once the testing concludes and the regulations appear, this is the emergency service we’re going to be living with for the next 20 years.”
Ganesh Pattabiraman, co-founder, president, and chief operating officer at NextNav, adds that in addition to providing data to drive regulation, the testing “brings awareness to the public safety operators and the FCC that here are reliable technologies that can address the problem of indoor location. As opposed to 10 years ago, or even six years ago. Not just ours, but others too.”
According to the NextNav website, “For devices equipped with NextNav’s technology, when a subscriber calls 911, the first responder won’t be left guessing about where they are. Providing a unique height capability, with vertical precision of up to 1 – 2 meters, first responders can move rapidly to the correct floor to ensure that not a second is wasted in the emergency response process. NextNav’s transmission is encrypted, secure and is available for carriers as a standalone service for E911 only. A carrier can implement the NextNav solution to enhance location performance of the E911 system separate from any decision to use NextNav capabilities as part of their commercial location-based services.”
Pattabiraman continues, “The need for accurate indoor location is greater [than for outdoor], but is the technology and the cost to the wireless carriers of implementing it up to the task? It all comes down to economics. If we or anyone can provide a solution that is incremental, reasonably priced, and commercially viable, then we can move forward.”
Particularly, he adds, “If we can build on the existing blocks of GPS at minor incremental cost, then we see the possibility of delivering the best possible accuracy for the lowest price.”
Test Administrator and Parameters. TechnoCom, a location-technology-neutral business, is conducting the Bay Area tests. TechnoCom is an active contributor to the Alliance for Telecommunications Solutions (ATIS) Emergency Services Interconnection Forum (ESIF). The ATIS conducts long-term research that serves as a basis for CSRIC findings and recommendations. The two organizations have many of the same members, although CSRIC consists of FCC-nominated members who serve one-year terms and thus doesn’t have “the consistency needed to do good science,” in one participant’s words.
The TechnoCom test parameters consist, broadly, of: a variety of locations (environments) and building types (also known as morphology), multiple test spots in each building, and each test spot to have at least 100 test calls. Researchers are looking for an indoor ground truth accuracy of 3 meters, something that would warm the hearts of public safety responders, but a level which, other experts say privately, is highly unlikely to be implemented as a requirement.
Public safety advocates would ideally want 5 meters, to the extent of “knowing which side of a wall a heart-attack victim is lying on.” Technology vendors such as those supplying solutions for test would probably settle for a 50-meter requirement, even if their solutions can do better. That’s at least in part because they are caught between the public safety folks on the one side and the wireless carriers — to whom they must sell — on the other. The wireless carriers are the most conservative of all, and may not want anything more stringent that the current outdoor requirements: 50-meter accuracy 67 percent of the time, and 150 meters 90 percent.
TechnoCom will test the following locations:
Dense urban: a four-block area north of Market Street in San Francisco’s financial district; as one participant pointed out, this is still not the densest urban environment to be found in the United States. For that, you have to look at older, Eastern cities such as New York or Chicago.
Urban: San Francisco and downtown San Jose
Suburban: Santa Clara County (malls, homes, condos and some high-rises)
Rural: Between Gilroy and Hollister, California.
All kinds of structures, about 20, typically found in the four basic environments, will serve as test spots: high-rise, mid-rise, mall, apartment building, house, warehouse, and barn. Various test points will be sited in each as appropriate, probably at 5-floor intervals in multi-storey buildings.
This is the next frontier for personal and machine navigation — and many are out there now, working diligently on it. In just one example, a new chip fuses input from several sensors, using the best combination at any given time to maximize coverage and accuracy while keeping power draw to a minimum. This produces continuous position availability in indoor environments, as demonstrated by performance measurements in real-world test environments.
The senior product manager responsible for this development joins us to talk about the inner workings and the outer manifestations of this new solution. He’ll be joined by other guest experts to be announced.
J. Blake Bullock was senior product manager responsible for CSR’s next generation of GNSS solutions. He has now transferred to Samsung System LSI Business and is responsible for GNSS and indoor positioning solutions. He holds a M.Sc. degree in geomatics engineering from the University of Calgary, an MBA from Arizona State University, and several patents in LBS and navigation.
At the magazine’s annual Leadership Dinner, held during the ION-GNSS Conference, we gave the first GNSS Leadership Awards to four individuals for their respective work in the four fields of satellites, signals, services, and products. We asked each recipient to give us a vision of the future: upcoming work, whether that’s something they plan to undertake or they think someone else should get going on, new directions for the industry, and so on. I asked them to ruminate as speculatively and as far into the future as they wished to go. Here’s what they told us.
These are not lifetime or career achievement awards, but recognition of significant contribution in the last year or two. Think of them as the Oscars, the Academy Awards of GNSS, if you will, for significant recent achievement.
Several people were nominated in each category by a small group, then voted on by a larger group of about 40, including the magazine’s Editorial Advisory Board, the contributing editors, and a dozen industry executives.
Here are the award recipients, followed by their remarks to an audience of 200 GNSS international VIPs attending the GPS World dinner.
In the Satellitescategory: Martin Unwin and the Surrey Satellite Technology Team
Principal engineer, SSTL.
For work on the GIOVE-A and Galileo IOV satellites, and on space-borne receivers
In the Signalscategory: Todd Humphreys
Director, Radionavigation Laboratory, and assistant professor, University of Texas at Austin.
Leader of several seminal studies on spoofing and jamming; testified this summer before Congress on the subject.
In the Servicescategory: Waldemar Kunysz
Senior staff engineer, NextNav LLC.
Forwork on Wide Area Positioning System (WAPS) design and implementation in the continental United States.
In the Products category: Robert Lutwak
Chief scientist, Symmetricom.
For practical advances to overcome the intrinsic physical barriers to affordable chip-scale atomic clocks, enabling precision time and time transfer in mobile GNSS and communications systems.
Now, their remarks.
Martin Unwin, honoree in the Satellites category.
Martin Unwin
Principal Engineer, Surrey Satellite Technology Team
“I feel privileged and honoured to receive this award from GPS World.
“With respect to the achievements in GIOVE-A and Galileo, I cannot claim this award on behalf of myself, but I will claim it on behalf of the people in SSTL who made the projects possible, and to those in the team here who have been working tirelessly to make the payloads and satellites happen. We are of course partnered with others in Europe that have been labouring equally hard, so it has been a true team effort.
“With respect to the spaceborne GPS and GNSS activities, my achievements have only been possible thanks to the top class staff we have in the receivers team, and thanks are also due to the support we have had from the rest of SSTL.
“In the 20 years I have been in the company, Surrey Satellite Technology Ltd has grown from a small University-based department to a major player in the international space scene, and I am immensely proud to have been part of this story.
“A few words for the future:
“Whilst it cannot quite match the early heady days of GPS, I still think nevertheless we are entering an exciting time in the GNSS world. We have two operational systems, and within a few years, we will be seeing two more reaching operational capability. Dual-, even triple-frequency civil signals will soon become operationally available, and some very wide bandwidth signals will be sent down, in particular, by Galileo. There is bound to be a steep learning curve in understanding how to exploit these new signals, with a few crevasses to be negotiated during the climb. But these new signals are bound to lead to an expanded vista of increased accuracy and robustness, and undoubtedly some unexpected destinations.
“Taking perhaps the highest perspective, spaceborne remote sensing is a good example that has surprising relevance to the rest of us still on the ground. In this case, GNSS satellites are used as radar sources, and all that is required on a low Earth orbiting satellite to change the world is a GNSS receiver. GPS Radio-Occultation measurements from low Earth orbit are now already the third most important data source for our global weather forecasts, thanks to the like of the COSMIC and MetOp satellites. Furthermore a new constellation of satellites called CYGNSS has recently announced by NASA that will be using ocean-reflected GPS signals to probe inside hurricanes and typhoons, and for the first time will enable the sensing of the wide-scale ocean roughness, leading to improved global wind and wave knowledge.
“By adding to this spaceborne receiver the ability to accommodate signals from Glonass, Galileo and Compass, plus any other available GNSS-type signals, the number of measurements is instantly quadrupled, and a new capability in sensing the atmosphere, waves and even ice and land is likely to be seen. Meteorologists already view GPS as an emerging utility for weather and climate sensing, but I think this new role for GNSS will be reinforced and expanded into yet another area where GNSS incontrovertibly, if indirectly, makes such a significant difference to our daily lives.
“As with many other applications where GNSS has become important or even critical to our modern world, this is, at the same time, both a blessing and a matter for some caution.”
Todd Humphreys, honoree in the Signals category. (credit: Mark Cowart)
Todd Humphreys Director, Radionavigation Laboratory,
and Assistant Professor, University of Texas at Austin
“It’s a genuine honor to receive this award. I’d like to thank Alan Cameron and all the contributors to GPS World. GPS World plays an essential role in building our GNSS community and keeping it together, providing GNSS news, instruction, and, indispensably, gossip!
“I’d also like to thank my students at the University of Texas Radionavigation Lab. Much of the credit for this award goes to them
“The futurist Ray Kurzweil spoke at a conference I attended back in 2001. Maybe some of you have heard of Ray. He’s regarded variously as a prophet, or a crackpot. He’s taking hundreds of vitamins every day to keep himself alive until the singularity arrives, at which point he’ll download himself onto a robot and live forever, or at least he’ll have his head cryogenically frozen so that he can be downloaded and live forever later on.
“In that 2001 talk Ray made some bold predictions. One, in particular, I remember well. “Within the decade,” Ray assured us, “we’ll all be wearing special contact lenses that give us a permanent Internet feed directly to our eyeballs.” Nonsense, I thought, and indeed it was nonsense. Here we are in 2012 and no such contact lenses exist, never mind their being in widespread use.
“I resolved back then that if I were ever called on to peer into the future and tell what I see, as Alan has asked me to do tonight, I’d be more modest about it.
“So tonight I’m going to make a modest prediction, and only one of them. I predict that by the GPS World dinner in 2020 carrier-phase differential GNSS, or, if you prefer an adjective for what should be a noun, Real-Time Kinematic, will be cheap and pervasive. We’ll have it on our cell phones and our tablets. There will be app families devoted to decimeter- and centimeter-level accuracy. The consequences will be fantastic. And this will be enormously disruptive to the current precision navigation industry. This will be the commoditization of centimeter-level GNSS.
“Now you may very well object to this prediction. You might point out that integer ambiguities will be difficult to resolve in the face of the near-field effects around and poor placement of the GNSS antenna in handheld units. You might also argue that the increased power requirements of carrier-phase techniques will be a dealbreaker for mobile devices. That’s all fine. I agree that those are hard problems. My students and I are looking into them, trying to overcome them.
“But please don’t make as one of your objections the one that I’ve heard so many times: “Why would anyone ever want cm-accurate positioning in their cell phone?” Because I’ll object that your objection lacks imagination.
“To see one example of what could be done with commoditized centimeter-accurate GNSS, I invite you all to a presentation by my students Daniel Shepard, Ken Pesyna, and Jahshan Bhatti tomorrow in the F5 Session (Millimeter-accurate Augmented Reality Enabled by Carrier-Phase Differential GPS). They’ll show off a crude box that we’ve built, through which, if you peer, you can see a sandcastle that’s not really there. And you can walk around the sandcastle and see it from all sides with centimeter accuracy.
“Imagine when this technology is in our tablets! Or, better yet, when it’s in our glasses — or, I suppose, our contact lenses. Not that I’m making any predictions about contact lenses…”
Waldemar Kunysz, honoree in the Services category. (credit: Mark Cowart)
“Ladies and gentlemen: I am much honored to receive this award and recognition. It means a lot to me.
“I would like to thank people that made difference in my career, without them it would not be possible to be here.
“First I am grateful to Dr. Maurice Meyer, former MIT professor. He taught me the black magic of antenna engineering.
“I am quite sure that his spirit guided me when I invented GPS/GNSS “Pinwheel” antenna when working at Novatel for which I received 6 patents. I also would like to thank Prof. Gerard Lachappelle and Dr. AJ Van Dierendock for teaching me GPS technology and to Dr. Phillip Ward to provide very useful insight to subject of interference. That knowledge saved me countless hours when troubleshooting some system level issues when designing the current and past GPS/GNSS products.
“Currently I am working at, LLC developing a new terrestrial based Wide Area Positioning System (WAPS). NextNav is a start-up company based in Silicon Valley that already, in its short life, has designed a new system that is being deployed in 40 major urban cities in the continental USA. This system will allow receiving a GPS look like signal in the areas where the coverage is weak or non-existent like indoors and dense urban developments (i.e. downtowns, urban canyons, etc.). We have already over 50 beacons installed in the San Francisco area that allows indoor and outdoor positioning anywhere from San Francisco to San Jose.
“As we know all major terrestrial systems have been shut down in the past several years such as Loran, Omega, Decca, etc. We became very dependent on satellite based services such as GPS and Glonass without any terrestrially based back-up. Any major solar storm in future could be very disruptive to this service so having a terrestrial based system that is in sync with satellite based system will fill that void.
“The future looks very bright for the positioning service industry. In my opinion, by 2020 it will become another utility such as phone or power. I’d like to agree with my other awardee and predict that in 2020 we will be able to have a carrier-based positioning accuracy anywhere and anytime available from any devices including handheld units. You will know where all your assets are and you won’t need to post a question to your wife: “ Honey, did you see where my tie is?”, your personal digital assistant will locate it for you.
“Thanks again everyone for being here.”
Robert Lutwak, honoree in the Products category. (credit: Mark Cowart)
Robert Lutwak
Chief Scientist, Symmetricom
“Thank you, Alan, for the introduction. Thank you also to the awards committee and especially to the individual who nominated me.
“Alan requested, repeatedly and forcefully, that we keep the sentimentality to a minimum, but I would be remiss if anyone left here with the impression that the development of the Chip-Scale Atomic Clock was in any way a solo effort.
“On the contrary, while I have had the privilege of being the “front man,” the success of this program can be attributed entirely to the fantastic collaboration between three highly disparate groups, from very different industries and cultures, including our Research Group at Symmetricom’s Technology Realization, in Beverly, Massachusetts, the MEMS group at The Charles Stark Draper Laboratory, led by Mark Mescher and Matt Varghese, and the optoelectronics group at Sandia National Laboratories, led by Darwin Serkland. If any of these groups and people had been anything less than extraordinary, both technically and personally, I would not be standing here this evening.
“With this introduction I can say, with little loss of humility, that the Chip-Scale Atomic Clock is a really cool device. Depending on where you’re coming from, it’s either 100X lower size, weight, and power (SWAP) than traditional atomic clocks or it’s 100X more accurate than quartz oscillators with comparable SWAP. Regardless of your perspective, it clearly represents a disruptive technology and paradigm shift for portable battery-powered navigation, communication, and timing applications. For comparison, the CSAC can run for a day on a full cellphone battery charge whereas the next lowest power clock of comparable performance will run down a car battery in an hour. The CSAC is not an evolutionary improvement in SWAP, it is revolutionary in that it enables previously untenable system architectures, mission scenarios, and network topologies.
“Since Symmetricom introduced the first commercial CSAC, roughly 2 years ago, the market response has been overwhelming. Despite having done our due diligence to predict the market demand and despite having nearly doubled our manufacturing output every quarter, our shipment backlog remains strong and I am frequently surprised by innovative customer applications that we had not envisioned at the product launch. We have to date shipped many thousands of CSACs to over a hundred different customers, representing vastly different markets and applications. While many of the novel applications are still in the early stages of prototype development and evaluation, it is clear that CSACs will be ubiquitous across diverse applications within the decade.
“I am fortunate, in my position, to interact directly with the technical integrators of the CSAC and learn the details of many of the applications. My general impression is that the timing and frequency stability performance of the CSAC is adequate for most of the emerging applications. The most common requests that I hear from customers are for reduced cost, power consumption, and size, in that order. It is not surprising that size is at the bottom of the list — in most applications, the batteries are still larger and heavier than the CSAC, so small improvements in power consumption are generally more valuable to reducing system SWAP than size reduction of the CSAC itself. As in any new technology, the cost will come down naturally with increased volume and improved manufacturing efficiencies, both at Symmetricom and at our vendors. While it is unlikely that you will get a CSAC in your next free cellphone, I do expect that the cost will progressively decrease over the next several years and the technology will become cost-viable to an exponentially increasing spectrum of applications. Similarly, we continue to evolve our electronics and algorithms for improved power consumption, aided by external advancements in microwave and microprocessor electronics driven by the smart-phone industry. It is my expectation that a factor of 2X improvement in power consumption is likely within the next three- to five-years.
“To date, most of the commercial products that have emerged, based on CSAC technology, have been in the timing and frequency calibration space. It is not surprising to me that the time and frequency community was the first to adopt and exploit the technology as many of them have been closely monitoring the development program and had the internal expertise and experience to rapidly exploit it.
“I admit, though, that I am a bit disappointed to see that there are no papers with “CSAC” in their titles at the 2012 ION-GNSS, but I am confident that this will change in the years to come. Adoption of CSAC by the navigation community has lagged behind the timing community in large part, I believe, because the technology has caught the community somewhat off-guard and the benefits of the CSAC to INS and GNSS are just now beginning to be realized.
“The most obvious and straightforward application of CSAC to GNSS is rapid P(Y) acquisition and we have demonstrated 15s time-to-subsequent-fix (TTSF) after two hours of GPS denial. This was a fairly simple demonstration that simply consisted of jamming time into an unmodified GPS receiver, but I believe that this is just the tip of the iceberg. With access to the core navigation algorithms within the receiver, precise knowledge of time could improve the receiver performance and reliability on other levels, including (at least):
Improved uncertainty of the navigation solution
Navigation with less than four (or less than three) satellites
Anti-spoof and anti-jam detection
Seamless co-integration of GNSS and INS systems
“Another navigation area that I believe is ripe to benefit from CSAC technology is in self-assembling navigation systems, e.g. a local ad hoc GNSS-like network which self-assembles from handheld timing beacons/receivers. Such a system would have value for safety-of-life applications in GPS-denied environments, such as indoor firefighting and mine safety.
“Thank you again for the recognition and opportunity of this award.”
We have heard it before, in various fora and in various forms: the GPS program is a victim of its own success. Because the satellites are living so long, launches of new, modernized space vehicles get deferred. And deferred. And deferred. The U.S. Congress meanwhile, for whom “defer” is a code to live by, happily pounces on this as an excuse to cut the GPS budget. And cut again the next year. And cut again.
As my colleague Eric Gakstatter reported from the Civil GPS Service Interface Committee (CGSIC) States and Local Government Subcommittee meeting, August 17, in Seattle:
“Of the 12 Block IIF GPS satellites being built, two are in orbit with the first being launched in 2010 and the second one last year. A third is scheduled to launch later this year [On October 4, in fact, perhaps by the time you read this column —Ed]. That equates to one launch per year.
“Clearly, this pace cannot continue or it would be 2022 before all 12 IIFs were in orbit. What’s the problem?
“Part of the problem is that the legacy Block IIA model satellites have performed so well. In fact, one has been operational for 22 years. That’s an incrediblefeat for a satellite that was designed with an expected life of 7.5 years. Unfortunately for the IIF program — and for the high-precision user community — it means that Congress can defer a few hundred million dollars per year by delaying the IIF launches. In these budget-conscious economic times, it’s not difficult to understand the reasoning that if there are 31 operational GPS satellites in orbit, why spend $150–200 million to launch each GPS satellite when we don’t need it yet? But that won’t last for long. The many legacy GPS satellites are one component failure away from being unusable. That said, the word at the CGSIC meeting is that three IIF satellites will be launched in 2013.”
An energetic online discussion sprang out of this column, with one reader exclaiming, “Finally someone stops arguing that the launch segment is the bottleneck. The budget segment is the actual bottleneck!”
The point is well taken. Since inception of the system, the standard text is that GPS consists of three inter-related segments: space, ground, and user equipment. Actually, there is a fourth segment, every bit as important as the other three: the budget segment.
It takes all four to deliver a PNT solution.
Engineers across the GNSS community industriously modernize the space vehicles, the ground control systems, and make leaps and bounds in überupgradesof receivers, chips, antennas, software, and just about everything else you can think of. And this is not just for GPS, but for GLONASS, Galileo, Compass, and QZSS too.
Meanwhile funding bodies grind along with the same ol’ same ol’.
The 2007 action film of that name concerns a domestic criminal plot, disguised as a terrorist attack upon U.S. infrastructure: an Internet-based hack into Federal Bureau of Investigation computers, the transportation infrastructure, the stock market, national video broadcast channels, the utility power grid, the National Security Agency, and the Department of Defense nerve center. One of the film’s two heroes recognizes this as a fire sale, an attack upon the nation’s computer controls, an attack in which “everything must go.”
Inspiration for the film came from a 1997 article in Wired magazine, “A Farewell to Arms,” written by John Carlin. “For those on the ramparts of the world’s sole superpower, the digital winds are blowing an icy chill through the triumphant glow of the post-Cold War,” the article begins. “Suddenly, the satellites over North America all go blind . . .” it envisions in mid-stride.
As prescient as the 1997 article is, and as slam-bang inclusive of almost every bit of taken-for-granted infrastructure as the 2007 actioner tries to be, neither one mentions GPS. There’s no reason why they couldn’t — they just didn’t. We can remedy that right now, with the following imagined scenario.
The placid mood of a lazy spring afternoon shatters at 4:53 p.m. Mountain Standard Time when the GPS constellation goes offline worldwide.
Long reliant on GPS timing for load management, electrical grids begin to move out of synch. A minor problem in a southern Illinois sub-station quickly morphs into a cascading power outage that plunges the North American continent into darkness.
The Pentagon command center detects a massive distributed denial of service attack underway on key areas of American military, utility, and aviation infrastructures. Air traffic flow systems are paralyzed, followed by train controls. Cellular networks collapse. Automatic cash machines and banking networks quickly roll down their shutters. All depended on GPS for positioning, navigation, timing, or all three; they simply cannot function without. Backups, long discussed but never deployed, can’t help.
Computerized transfer of information grinds to a halt nationwide. Mayhem ensues. Riots break out in large cities. Police forces join the ranks of the newly crippled, and are forced to deal with unrest in the old-fashioned way: going out into the streets on foot.
As a once-beautiful day descends into long dark night, confusion, desperation, and fear spread black wings across the world.
The information has been lost.
Doomsday scenarios go in and out of fashion. Lately they’re all the rage. I was startled by an April article in Smithsonian that led to my May editorial “That’s Denial.” But now I’m noticing these portents more and more.
Every benefit brings its own drawback, every strength its own weakness. The principle applies not only to technology, but to every branch of human endeavor, of the natural adaptive world, even to the laws of physics. We little realize how totally reliant our civilization has become on very precise information. Without backups, defenses, mitigation, and safeguards, even a momentary loss of information can wreak catastrophic effects. Witness the recent Facebook Fumble, described by Chuck Shue of UrsaNav at the ION PLANS meeting:
“On May 18, 2012 the ripple effect of two (2) extra milliseconds of delay required to calculate the opening price during the Facebook initial public stock offering produced damages to Facebook estimated from $40 million to $400 million — for one stock. Although not as widely known, Nanex reported that the timing glitch, probably from errors in routing software, also affected Apple, Intuit, Netflix, QualComm, Zynga, and other stocks.
“What if this were the result of time spoofing, rather than simply a programming error?” he asked.
This is the demonstrated effect of an accidental 2-millisecond delay, in one market of one sector of the national economy. In the case of a prolonged outage, a sustained attack by spoofing, jamming or other means, on the neural center of national infrastructure — that is, GPS — the mind staggers.
We live by lightning-quick transmission and exchange of data. We may just die by it. The cloud touted as the ultimate warehouse, routing center, and solution to business challenges may dump acid rain on our picnic one day.
Our world is driven by information flow in ways unfathomed just a few years ago — and don’t we love it? The technological and societal changes associated with computers, the Internet, Information-Age thinking, and all our neo-survival tools still manage to leave us extremely exposed.
Benjamin Wash, who originated the GPS doomsday scenario at the beginning and many other thoughts throughout this column, wrote “The data sea upon which we sail grows exponentially vaster, and ever more complex and vulnerable, by the day. Our reliance on and need to gain information advantage intensifies as the world becomes more digitally integrated and competitive. Resource competition among nations is fierce, and those who control information exercise control over resources to a greater extent than in any time in our history.
“Information access, flow, and aggregation enable the achievement of strategic and tactical advantage, but also the potential for mayhem. As an entity and as individuals, we cannot afford to be blind to this paradigm-altering reality: information drives the world.”
Our correspondent had more to say concerning the Congressional melee — only be sure to call it, please, negotiation — over the defense budget. GPS, although not perceived by most to be at the center of this, does actually occupy that critical, key position because of the way it coordinates everything else.
The proliferation of sophisticated electronic weaponry and technologies such as GPS jammers and spoofers, empirically evidenced in two articles in this issue, “Drone Hack” and “Going Up Against Time,” show just how vulnerable our golden standard is — and how saliently that vulnerability has emerged — in this information-based era.
The GPS constellation and its associated signals are the primary source of PNT information, which increasingly drives all other information domains in the nation, not to mention for our overseas combatants and coalition allies. Over the coming decades, rapid technological advances will further remake whole sectors of the national infrastructure and national security.
These improvements are contingent upon steady resource allocation within the Air Force. Future on-orbit systems, such as GPS III and its associated capability improvements, are under extreme budgetary pressure for their high cost. Some improved capabilities have already been shelved due to budget constraints, and more may follow. Key among these are strengthened defense of the system; only a few steps have been envisioned, and fewer taken. Many more mitigations, defenses, and backups must emerge from conceptualization into design, testing, and deployment.
Technology’s complexity makes buy-in by policy makers difficult. Technical advances, both achieved and anticipated, are hard to defend in the budget battles on the Hill. But that’s our job, so step up.
Let’s return briefly to the Carlin article. “For all the bustle, there’s no clear direction. For all the heat, there isn’t a great deal of light. For all the talk about new threats, there’s a reflexive grasp for old responses — what was good enough to beat the Soviet Union and Saddam Hussein will be good enough to beat a bunch of hackers. Smarter hardware, says the Pentagon. Bigger ears, says the NSA. Better files, says the FBI.”
Has anything changed since those words were written in 1997? Hardly.
There are no easy answers in the coming knife fights over the defense budget. Vital technologies will vanish under the flailing and battledust of political striving for personal and party advantage.
Decision makers must understand that information systems are the backbone of all we do — and that GPS drives more and more of those information technologies, through its micro-precise electronic timing.
It’s our job to educate lawmakers and beancounters. A letter to your three Congresspeople is a simple yet effective educational tool.
Unmanned aerial vehicles and civil aircraft may co-habit the airspace after September 2015.
As the U.S. Federal Aviation Administration (FAA) moves ahead with plans for unmanned aerial systems/vehicles (UAS/UAV) to have regular access to U.S. airspace by 2015, it has encountered several barriers. For UAVs to be treated like manned aircraft, their systems likley need to be qualified to the same standards as civil avioncs. This is a challenge, as each UAS has largely unique systems. UAS equipment standards are emerging, but threats to GNSS abound, requiring defense/mitigation.
Demand for UAS has produced many different types flying in a range of applications. With no apparent standard avionics fit or uniform safety standards, each UAS type is basically configured for specific tasks. Commercial UAS applications continue to emerge, and major market growth is anticipated. One forecast indicates that the UAS market could reach $7.26 billion this year alone. The promise of new and better ways to reduce costs, improve safety, and increase operational efficiency feeds market expansion.
However, in the United States the FAA currently requires each UAS commercial project desiring access to controlled airspace to obtain an FAA-approved Certificate of Authorization. While the FAA has made efforts to speed up approvals, this process slowed widespread commercial adoption of UAS. Nevertheless, opportunities abound in pipeline and transmission line inspection, crop spraying, law enforcement, security, and surveillance, survey/mapping, remote area mail delivery, and hundreds of other applications. The FAA may have felt some pressure to move forward, because Congress has put in place the Modernization and Reform Act of 2012, which calls on the FAA to fully integrate unmanned systems, including those for commercial use, into the national airspace by September 2015.
UAS in the NAS. Meanwhile, a project called the Unmanned Aircraft Systems Integration in the National Airspace System (UAS in the NAS), undertaken by NASA’s Dryden Flight Research Center, seeks to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS.
Europe has also launched a study on the integration of UAS in non-segregated airspace for the future Single European Sky. The ICONUS study will be carried out by a consortium within the European air traffic management program called Single European Sky ATM Research Programme (SESAR). The study will drive the definition of the requirements, capabilities, and equipment which UAS will need to operate safely and efficiently in the coming European SESAR environment.
The U.S. RTCA SC-203 committee is drafting UAS operational requirements, and there has been significant progress towards publishing Minimum Aviation Performance Standards (MASPS), including requirements for navigation. Europe has similar activities underway aimed at improving UAS access to its airspace.
MOPS. The big picture is that requirements for unmanned aircraft are being brought into conformance with the standards applied to the performance and behavior of manned aircraft. Navigation requirements for UAS are expected to specify that systems will need to be qualified to Minimum Operational Performance Standards (MOPS). This means that on-board electronics, including GNSS systems, will probably need to be FAA Technical Standard Orders (TSO) qualified, just as they are now for manned aircraft.
Why do we need to investigate certified avionics now? In the scheme of avionics, more than two years breathing space to certify UAS avionics systems is not a long time, not at all, until the September 2015 deadline. FAA airborne software and hardware qualification will take much time and effort to implement, and re-configuration of systems, interfaces, and operating procedures may take even longer.
For Manufacturers. UAS makers have the option to move forward in stages. For instance, by selecting a few existing airborne-qualified OEM avionics, they could minimize the internal effort to comply. As the first UAS with certified avionics emerge, they will probably get good support from FAA to adopt U.S. operating rules for the NAS. Embedding an existing certified GPS receiver in UAS avionics will reduce the internal work needed and allow more effort for developing commercial market opportunities that look to quickly adopt UAS.
Meanwhile, efforts are in full swing to change the U.S. and European navigation landscapes over the next few years. So it would be better to be ready with a capable GNSS receiver that is already built to meet the challenges of NextGen and SESAR.
GPS III and Galileo. The L5 civil GPS frequency may be operational around the time that UAS unrestricted access becomes possible. GPS L1/L5 dual-frequency operations will enable higher navigation accuracy, reliablity, and integrity. The FAA is already developing NextGen WAAS to include L5, and revisions to the GPS MOPS to include L5 should begin shortly, in time for a usable GPS L5 constellation in 2015/2016. The FAA is already preparing for L5 avionics, and industry investigative work is underway. Its possible that GPS L1/L5 may meet the accuracy and integrity requirements for CAT II/III automated landings. In Europe, Eurocae work is expected to gain momentum for the Galileo E1/E5a MOPS as the Galileo satellite navigation system becomes operational.
The new GNSS environment also includes WAAS/SBAS precision approach (localizer performance with vertical guidance, or LPV) capability: LPV is available now in the United States and will soon be in wider operation in Europe. Automatic Dependendant Surveillance (ADS-B) is rolling out in the United States and around the world. ADS-B is being mandated within the U.S. NAS as the means for air-traffic control to track all aircraft, so UAS avionics will need to include certified ADS-B Out capability.
In one commercial instance, the Septentrio AiRx2 receiver comes out of the box as a certified L1 GPS with ADS-B and WAAS LVP, but is also ready for GPS L5 and Galileo E1/E5a.
Even as greater steps forward enhance how GNSS is used in this wider definition of aviation that will soon include UAS, a team at the University of Texas demonstrated how a UAV could be maliciously side-tracked (see article on page 30 of this issue) — reminiscent of the Iranian downing of a U.S. surveillance drone in December 2011.
Admittedly the GPS on the vehicle in the UT test was not a qualified airborne receiver, but how could this happen when there was also an inertial sensor and a radio-altimeter on the UAV? A good question, which UAV manufacturers will need to consider when they implement their on-board Kalman filters, knowing that spoofing is now an additional threat to parry.
Couldn’t we detect that high-power RF spoofing signal at the front-end of the GPS receiver? Even if only to tell the on-board systems that there could be hazardous misleading information about? Or run separate GPS and GPS/inertial position solutions, detect significant divergence, and set the same warning flag? And multi-constellation, multi-frequency receivers, and even controlled radiation pattern antennas — all things to investigate. More work for the aviation receiver guys who labor tirelessly to improve GNSS integrity.
Of course if you hijack a UAV with a high-power spoofer, you are also spoofing civil transports operating in the same airspace, so now there is the potential to trigger a Federal investigation. It will probably be easier to detect this stuff with moving airborne sensors rather than the fixed ground equipment used to find jammers on trucks at Newark airport, and lots of pilots likely providing real-time location information on radios if their GPS goes even a little haywire. All would help to quickly locate and shut down any spoofer. Nevertheless, it’s a threat to be mitigated.
Fatal Crash. In South Korea, the effects of intermittent North Korean jamming of GPS to disrupt seal, land, and air navigation in the South may have contributed to the recent fatal crash of a Schiebel Camcopter S-100 drone, a 150-kilogram rotorcraft capable of 220 km/h flight. It should have coped with loss of GPS as the Camcopter has multiple inertial measurement units that allow safe operation and recovery in the absence of GPS signals. Emergency procedures to ensure a safe recovery in such a situation do not appear to have been correctly and adequately followed, manufacturer Schiebel alleges.
NovAtel may have found one way to help mitigate spoofing on UAVs; the company released a combined civil/SAASM GPS receiver, the OEM625S, aimed specifically at UAVs. Granted, the idea is to add SAASM anti-spoofing capability to a number of UAVs which currently use NovAtel commercial receivers, mostly in military systems. That may be motivated by the desire to avoid further Iranian incidents!
BAE Systems has been thinking of giving GPS a back-up for just those situations where jamming or even spoofing is detected. BAE’s Navigation via Signals of Opportunity (NAVSOP) system was just announced at the Farnborough air show in the UK and is still in research phase, but looks extremely promising. It interrogates the radio environment for the ID and signal strength of local digital TV and radio signals, plus air traffic control radars, with finer grained adjustments coming from cellphone masts and Wi-Fi routers. Mapping the location of all these sources might be quite an undertaking, and given that these are all non-safety-of-life commercial signals, the sources are subject to the vagaries of power outages, regular maintenance, and breakdowns. Nevertheless, with such a multitude of signals, NAVSOP could well turn out to be a viable back-up for GNSS.
So, shared access to civil airspace, wider applications in commercial operations, and changes in equipment qualification, along with potential solutions for GNSS jamming and spoofing: lots to consider for the UAS industry.
Taking It to the House
U.S. House of Representatives Committee on Homeland Security; Subcommittee on Oversight, Investigations, and Management; Hearing, July 19, 2012: Using Unmanned Aerial Systems Within the Homeland: Security Game Changer?
Testimony by Todd E. Humphreys, Ph.D.; Assistant Professor, Cockrell School of Engineering, The University of Texas at Austin. [Excerpted. Prof. Humphreys is a co-author of the article “Drone Hack” in the August issue of GPS World.]
The vulnerability of civil GPS to spoofing has serious implications for civil unmanned aerial vehicles (UAVs), as was recently illustrated by a dramatic remote hijacking of a UAV at White Sands Missile Range.
Hacking a UAV by GPS spoofing is but one expression of a larger problem: insecure civil GPS technology has over the last two decades been absorbed deeply into critical systems within our national infrastructure. Besides UAVs, civil GPS spoofing also presents a danger to manned aircraft, maritime craft, communications systems, banking and finance institutions, and the national power grid.
Constructing from scratch a sophisticated GPS spoofer like the one developed by the University of Texas is not easy. It is not within the capability of the average person on the street, or even the average Anonymous hacker. But the emerging tools of software-defined radio and the availability of GPS signal simulators are putting spoofers within reach of ordinary malefactors.
There is no quick, easy, and cheap fix for the civil GPS spoofing problem. What is more, not even the most effective GPS spoofing defenses are foolproof. But reasonable, cost-effective spoofing defenses exist which, if implemented, will make successful spoofing much harder.
I recommend that for non-recreational operation in the national airspace civil UAVs exceeding 18 lbs be required to employ navigation systems that are spoof-resistant.
More broadly, I recommend that GPS-based timing or navigation systems having a non-trivial role in systems designated by DHS as national critical infrastructure be required to be spoof-resistant.
Finally, I recommend that the DHS commit to funding development and implementation of a cryptographic authentication signature in one of the existing or forthcoming civil GPS signals.
The potential vulnerabilities of U.S. national transportation, communications, banking and finance, and energy distribution infrastructure;
What does it take to build a spoofer? Buy a spoofer?
Range and required knowledge of target.
Fixing the problem:
• Jamming-to-noise sensing defense;
• Defense based on SSSC or NMA on WAAS signals;
• Multi-system multi-grequency defense;
• Single-antenna defense;
• Defense based on spread-spectrum security codes on L1C;
• Defense based on navigation message authentication on L1C, L2C, or L5;
• Correlation prole anomaly defense;
• Multi-antenna defense;
• Defense based on cross-correlation with military signals.
Two British technologists backed by the U.K. Ministry of Defense have filed patents on the future interoperable GPS and Galileo signal designs that severely disrupt modernization plans for both systems and suddenly, unexpectedly place receiver manufacturers in a highly uncertain and unfavorable situation. Some of the patents have been granted in the U.K. and in Europe, and applications are pending in U.S. patent court, with a ruling expected at any time.
Companies in the United States and outside the country are being approached and asked to pay royalties, on the basis of the patent filings, for use of the European E1 Open Service signal and the modernized GPS L1C signal. Should such initiatives prevail, costs would presumably be passed along to end users of GPS and Galileo — the same taxpayers who have already paid once for the systems.
The purveyor of the royalty solicitations is Jim Ashe, vice president for sales and intellectual property at Ploughshare Innovations Ltd., Hampshire, UK. The patents, if successfully used to collect fees from satellite manufacturers or receiver manufacturers, would have a chilling effect on the use of the new interoperable signals that all parties have labored so hard, for so long, to design. They could quite possibly lead to a return to a BOC(1,1) structure for these signals, losing the benefits of MBOC.
“There’s quite an argument going on,” said one person familiar with the controversy. “Some of the methods of arguing have not been too kind.”
The Background. A great deal of work was accomplished cooperatively between the United States and the European Union (EU) to develop the landmark 2004 signal agreement that emerged from the Galileo Signal Task Force, formalizing cooperation on satellite navigation between the United States and more than two dozen European countries, including the U.K. Part of that agreement concerned a common signal structure (spectrum) for the civilian signals for both the E1 Open Service (OS) signal — the Galileo equivalent of GPS L1 — and the new U.S. GPS L1C signal to be implemented on the GPS III satellites, coming as early as 2015.
The EU said during that process, in effect, “Even though we have agreed on this, Europe wants to be able to optimize the E1 OS signal beyond the agreement on that civilian signal being a binary offset carrier BOC(1,1) signal.” Both international entities had agreed that would be the waveform or the spectrum of the new signal.
The Europeans began to evaluate methods of optimizing their signal. They had some designs called composite binary coded symbols (CBCS), a mechanism of putting a higher frequency componenent into the signal structure, and also a version called CBCS*, meaning that they found there was a bias generated by that extra signal, and so they had to invert every other one of its repetitions.
The signal structure that they were playing with was centered on a plus and a minus 5-MHz component. (Actually five times 1.023, because of the inherent clock of GPS, you can think of it as 1.023 MHz. Everyone in doing compatible or interoperable signals agreed upon that; when reference is made to 5 or 10 MHz, or an even 5 or an even 10, it means that number multiplied by 1.023).
The Europeans were were putting an additional BOC signal on top of the BOC 1,1, and it would have plus or minus 5 MHz as the centers of those two BOC peaks, and then some kind of waveform to modulate that.
The United States pushed back against that to some degree, and proposed adoption of the so-called MBOC waveform, in which case the U.S. signal was equally optimized with a concept called time-multiplexed BOC (TMBOC). The Europeans used the CBOC approach. So, very different ways of doing this. In the European way, they transmitted a continuous but very low-power BOC(6,1) term. The U.S approach transmits four BOC(6,1) chips out of every 33 chips of code (see “Future Wave” sidebar).
A chip in this case means a part of the spreading code, so each signal has its spreading codes, just like the C/A code is a spreading code, meaning a pseudorandom code modulating the carrier. L1C and E1 OS have a pseudorandom spreading code.
The U.S. approach does not put BOC(6,1) components onto the data; that’s what is commonly called MBOC. The U.S. approach is TMBOC, on the pilot carrier only, not on the data component. The European system is like two separate signals, the BOC(1,1) signal having both pilot and data, and a BOC(6,1) signal having both pilot and data. They’ve put the (6,1) into both data and pilot components.
Cue the Antagonists. Part of the task force from Europe and the United States considering the future signals’ make-up were Tony Pratt and John Owen, who works for the U.K. Ministry of Defense and whose office sponsored Pratt’s work. The two participated heavily in all these signal discussions. They stated in early meetings they planned to file patents in some areas.
“Frankly,” states one source, “people should have paid more attention when they said that, and asked ‘What do you mean, and how’s it going to work, etcetera?’ And secondly, there probably should have been a written agreement between parties that nobody will take advantage or patent any of these ideas that we are developing.”
Pratt and Owen filed a number of patents domestically, in the U.K., and and in the European Union, in 2003 and in 2006, and in other places around the world, such as Japan, Canada, and in the United States as well. Some of the U.K. and European patents have been granted. The first of some of those U.S. patents may be issued in the near future.
The original patent filings were later amended to include new claims. The new claims were much more specifically oriented toward TMBOC and CBOC, whereas the original claims were more generally oriented toward modulated methods. The claims have been modified over the years; this is fairly standard patent practice.
As a result, the original 2003 patent doesn’t necessarily read on a particular signal, but its early filing date has precedence. The claims have been updated and modified, and if the patent office issues those, as a true patent, then the new claims apply. Plenty of big patent battles have been fought over just such issues.
Once the patent is issued, a satellite or receiver manufacturer must assume that it is valid, and has only two responses to make, other than acquiescing to royalty claims. The manufacturer can either say, if building a product, “No, my product does not infringe, and I will prove that it doesn’t.’” The other choice for manufacturers is to go back into the patent office and sue the patent filer (and grantee) in the patent courts and prove that the patent was invalid in the first place that the patentee should not have been granted it.
The United States and others were taken off-guard when the U.K. company Ploughshare, which is owned and controlled by a part of the British MoD called Defense Science and Technology Laboratory (DSTL), started making claims on manufacturers. The DSTL is similar to the U.S. Defense Advance Research Products Agency (DARPA), which is credited with inventing the Internet. If taxpayer money goes into something new and interesting, it is considered in some circles legitimate to file patents on those and attempt to recover taxpayer money through royalties on that taxpayer investment. That concept is not being challenged. Questions as to whether the patents are legitimate are very much in discussion.
Ploughshare has contacted companies, saying, “If you use these signals coming from either the European satellites or the U.S. satellites, we will go after companies using these signals.” There are different patents issued, one by the European Patent Office, applying to most of the EU countries, that applies directly to the TMBOC signal, the E1 OS signal, and possibly also to Europe’s E5 signal, which is E5a and E5b; and there is also a patent for GPS III, the L1C signal.
“If you take the patent that hits TMBOC, and you take the broadest possible interpretation of that patent against receiver companies, it says: if you bring into your antenna and process that signal, whether you use all parts of it or not, for instance if you use the BOC(1,1) and not the BOC(6,1) part — then you infringe the patent. Others argue that if you don’t use both components, you don’t infringe.
“But the claim is written broadly enough that it would apply to any receiver receiving and processing the signal. Nobody says what processing means. The patent says if you receive and process the TMBOC signal, as defined in the prior claim, you infringe the patent.
“There is confusion as to whether that will apply or not apply — some people expect that it doesn’t and some people think that it might. That’s up in the air.”
George Is Getting Upset. Various factions in the United States are upset by and trying to figure out what to do about the impasse. From a government point of view, there are three paths that the U.S. government can follow:
Put pressure on the U.K. diplomatically. That would be up to the State Department to put pressure on the EU or the U.K. in particular. The EU and the continental Europeans are equally furious at the British for doing this, as far as parties in the U.S. understand. This can’t be stated as a fact but is widely understood and thought to be the case. The diplomatic approach has its limits, obviously.
Go into Europe and fight the patents in European patent court and try to prove them invalid, to invalidate the patents. Companies could do the same thing, go into various courts, whether they be U.S. or European or Japanese, and say: “Our receivers don’t infringe,” and then have to prove that to the court; or say “The whole patent should not have been allowed, and I’ll fight the legitimacy of the patent.”
Some believe — and there is controversy and anger on this point — that, just as Galileo’s IOV satellites have the capability to transmit without the BOC(6,1) component, the United States should be able to do that with the GPS III satellites as well. Because if the signal is not there, and if the receivers are therefore not designed to process the signals that are not there, then the patent no longer has any relevance.
“If we are to turn off the BOC(6,1) term for a period of time until the legal or diplomatic or other approaches worked, then we would be able to turn the BOC(6,10) term back on again, and return to the original agreed MBOC and TMBOC signals. That requires some coordination between the United States and Europe, and it requires some work to make that possible in the GPS III satellites, putting a switch in the GPS III satellites to permit the operators to turn that (6,1)BOC on and off. This is being hotly debated.”
Some parties object, stating that L1C is too important a signal to mess with, and this proposal runs the risk of slowing down the program, and/or making it more expensive. They believe strongly that the off/on switch is not the best or most far-sighted option: why should the United States be forced to change its signal design due to an illegitimate patent, and in the end wind up with a less capable system?
It is not publicly known whether the Air Force is or is not looking into that option.
During the week of June 25 there was Working Group-A meeting in Washington D.C. followed by a plenary meeting between the EU and United States. The patent controversy was presumably discussed in some fashion, but whether formally addressed or lurking in the background is unknown at this time.
“There is some naivete around this,” said the magazine’s soure. “It’s a serious threat. People think maybe they’ll only go after the high-end receivers, and maybe the royalties won’t be so bad. Ploughshare is trying to lull people into a false sense of security. The impact of this will be great unless it is defeated.”
“The L1C waveform originally was to have been a pure BOC(1,1) (a 1.023 MHz square wave modulated by a 1.023 MHz spreading code). Negotiations between the U.S. and the European Union (EU) at that time resulted in an agreement that both GPS and Galileo would use a baseline BOC(1,1) signal. However, the EU reserved the right to further optimize their signal within certain bounds. Some of the optimization proposals were known as CBCS and CBCS*. However, in further EU/US discussions it was decided that L1C and the Galileo E1 open service signal should have identically the same spectrum. This was a significant challenge because of different baseline signal structures and existing designs.
“The breakthrough came when [U.S. representative] John Betz proposed what is called MBOC. The MBOC waveform has 10/11th of its power in BOC(1,1) and 1/11th in BOC(6,1). However, L1C and E1 OS achieve this result in very different ways. The Galileo technique is called CBOC. The GPS technique is called TMBOC. Whereas Galileo has a 50/50 power split between pilot and data and includes the BOC(6,1) component in each, GPS includes the BOC(6,1) waveform only in the pilot component by modulating four of every 33 spreading code chips with a 6 MHz square wave and 31 chips with a 1 MHz square wave. With 75 percent of the power in the pilot, the result is 3/4 x 4/33 or 1/11, as required. It is likely the BOC(6,1) signal component will be ignored by consumer-grade GNSS receivers where a narrow RF bandwidth is preferred. Fortunately that is a loss of only 12 percent (0.56 dB) of the L1C pilot power. However, for commercial and professional grade receivers, the extra waveform transitions (wider Gabor bandwidth) can be used to improve code tracking signal-to-noise ratio, and with certain advanced techniques it should be possible to improve multipath mitigation. This final point depends on careful control or calibration of the transmitted code timing and symmetry.”
EGNOS and Galileo IOV Satellites Shift Right
The next EGNOS satellite, originally scheduled for a June 18 launch, now has a rise date of July 7 from Baikonur Cosmodrome in Kazakhstan. The launch was delayed by a problem with a first-stage subsystem on the Proton rocket. SES-5 is also known as Sirius 5, stemming from the development of the Sirius satellite constellation by Nordic Satellite AB, now owned by Luxembourg’s SES.
The satellite carries a transponder for the European Geostationary Navigation Overlay Service (EGNOS). The transponder is intended to eventually replace or one of those on the currently used EGNOS satellites (Inmarsat 3-F2 at 15.5 degrees west using PRN 120, Artemis at 21.5 degrees east using PRN124, and Inmarsat-4-F2 at 25 degrees east using PRN 126 and designated for industry tests).
Unlike the present L1-only EGNOS satellites, SES-5 will have transponders on both L1 and E5 frequencies similar to the Wide Area Augmentation System satellites, which broadcast on L1 and L5.
SES-5 is to be stationed at 5 degrees east longtiude.
A second SES satellite with EGNOS transponders is under construction. The SES Astra 5B satellite is scheduled for launch in the second quarter of 2013 and will be positioned at SES Astra’s 31.5 degrees east orbital position.
Role Switch. On March 22 and 23, Inmarsat-4-F2 at 25 degrees east using PRN126 and Artemis at 21.5 degrees east using PRN124 switched roles. PRN126 became an EGNOS operational signal-in-space satellite, while PRN124 became the test satellite, transmitting message type 0. PRN120 and PRN126 returned to service around 17:00 UTC on Tuesday, June 26.
According to an EGNOS service announcement dated April 3, the switch was due to the aging state of the Artemis satellite.
Galileo October Birds. According to a usually reliable source, the launch date for the second set of Galileo IOV satellites, previously announced as September 28, has been pushed back a couple of weeks to October 12.
Maybe we should take it as validation, an acknowledgment of the worth, maturity, and promise of the GNSS industry, that profiteers show up trying to make a fast buck. A prompt pound, a quick quid.
Or perhaps we should be angry at this violation of international trust, this grasping effort to monetize the free and open exchange of scientific ideas, this contravention of the very spirit and tradition of global navigation satellite systems and signals.
For no sooner have we dispatched the LightSquared wolves from our doorstep than others come knocking, saying they are entitled to a fee for something that everyone else has always given away.
See this editorial from my GNSS Design & Test newsletter for details and background on this controversy.
Not enough has been made, over the last two and a half decades, of what is arguably the United States’ greatest foreign aid project of all time, a free and open gift to the world: the continuous provision of PNT signals everywhere, at no charge whatsoever to users or to manufacturers incorporating the signals in their offerings. Other GNSS providers have followed suit in being openhanded and largely aboveboard, starting with GLONASS, continuing with a few stutter steps through Galileo, and probably concluding in like fashion with Compass, not to mention QZSS and other regional augmentations.
But now the United Kingdom’s military and/or a commercial spin-off and/or two scientists funded by same want to fence off an area of the open sky and say “This is ours and you must pay to use it.” Whether the two individuals acted on their own initiative, or were driven to signal-rustling by a strapped military looking to profit from someone else’s investment, or were prodded into adventurism by an overweening veep of sales and IP, we do not know at this point. Keep in mind, this is the same establishment that gave us the Charge of the Light Brigade.
Was there a man dismay’d ?
Not tho’ the soldier knew
Some one had blunder’d:
Theirs not to make reply,
Theirs not to reason why,
Theirs but to do & die.
One British scientist wrote an open email letter, excerpted here, to members of the international GNSS community:
“I would like to make it absolutely clear that this patent application has nothing to do with me whatsoever. I was required to work with both of the individuals named on the patent on other projects. However, I have never ever worked on GNSS signal design and certainly do not endorse their patent application in any way. I personally agree with those that consider this patent to be against the spirit of international cooperation under which the interoperable GNSS signals that we all need have been developed.
“I’m sorry to take up your time. However, my reputation is important to me.”
Would that others had thought of their reputations, not to mention the effect on the industry that nurtured them, no less the shackling of benefits to all humankind, before taking this step.
Two British technologists backed by the U.K. Ministry of Defense have filed patents on the future interoperable GPS and Galileo signal designs that severely disrupt modernization plans for both systems and suddenly, unexpectedly place receiver manufacturers in a highly uncertain and unfavorable situation. Some of the patents have been granted in the U.K. and in Europe, and applications are pending in U.S. patent court, with a ruling expected at any time.
Companies in the United States and outside the country are being approached and asked to pay royalties, on the basis of the patent filings, for use of the European E1 Open Service signal and the modernized GPS L1C signal. Should such initiatives prevail, costs would presumably be passed along to end users of GPS and Galileo — the same taxpayers who have already paid once for the systems.
The purveyor of the royalty solicitations is Jim Ashe, vice president for sales and intellectual property at Ploughshare Innovations Ltd., Hampshire, UK. The patents, if successfully used to collect fees from satellite manufacturers or receiver manufacturers, would have a chilling effect on the use of the new interoperable signals that all parties have labored so hard, for so long, to design. They could quite possibly lead to a return to a BOC(1,1) structure for these signals, losing the benefits of MBOC.
“There’s quite an argument going on,” said one person familiar with the controversy. “Some of the methods of arguing have not been too kind.”
The Background. A great deal of work was accomplished cooperatively between the United States and the European Union (EU) to develop the landmark 2004 signal agreement that emerged from the Galileo Signal Task Force, formalizing cooperation on satellite navigation between the United States and more than two dozen European countries, including the U.K. Part of that agreement concerned a common signal structure (spectrum) for the civilian signals for both the E1 Open Service (OS) signal — the Galileo equivalent of GPS L1 — and the new U.S. GPS L1C signal to be implemented on the GPS III satellites, coming as early as 2015.
The EU said during that process, in effect, “Even though we have agreed on this, Europe wants to be able to optimize the E1 OS signal beyond the agreement on that civilian signal being a binary offset carrier BOC(1,1) signal.” Both international entities had agreed that would be the waveform or the spectrum of the new signal.
The Europeans began to evaluate methods of optimizing their signal. They had some designs called composite binary coded symbols (CBCS), a mechanism of putting a higher frequency componenent into the signal structure, and also a version called CBCS*, meaning that they found there was a bias generated by that extra signal, and so they had to invert every other one of its repetitions.
The signal structure that they were playing with was centered on a plus and a minus 5-MHz component. (Actually five times 1.023, because of the inherent clock of GPS, you can think of it as 1.023 MHz. Everyone in doing compatible or interoperable signals agreed upon that; when reference is made to 5 or 10 MHz, or an even 5 or an even 10, it means that number multiplied by 1.023).
The Europeans were were putting an additional BOC signal on top of the BOC 1,1, and it would have plus or minus 5 MHz as the centers of those two BOC peaks, and then some kind of waveform to modulate that.
The United States pushed back against that to some degree, and proposed adoption of the so-called MBOC waveform, in which case the U.S. signal was equally optimized with a concept called time-multiplexed BOC (TMBOC). The Europeans used the CBOC approach. So, very different ways of doing this. In the European way, they transmitted a continuous but very low-power BOC(6,1) term. The U.S approach transmits four BOC(6,1) chips out of every 33 chips of code (see “Future Wave” sidebar).
A chip in this case means a part of the spreading code, so each signal has its spreading codes, just like the C/A code is a spreading code, meaning a pseudorandom code modulating the carrier. L1C and E1 OS have a pseudorandom spreading code.
The U.S. approach does not put BOC(6,1) components onto the data; that’s what is commonly called MBOC. The U.S. approach is TMBOC, on the pilot carrier only, not on the data component. The European system is like two separate signals, the BOC(1,1) signal having both pilot and data, and a BOC(6,1) signal having both pilot and data. They’ve put the (6,1) into both data and pilot components.
Cue the Antagonists. Part of the task force from Europe and the United States considering the future signals’ make-up were Tony Pratt and John Owen, who works for the U.K. Ministry of Defense and whose office sponsored Pratt’s work. The two participated heavily in all these signal discussions. They stated in early meetings they planned to file patents in some areas.
“Frankly,” states one source, “people should have paid more attention when they said that, and asked ‘What do you mean, and how’s it going to work, etcetera?’ And secondly, there probably should have been a written agreement between parties that nobody will take advantage or patent any of these ideas that we are developing.”
Pratt and Owen filed a number of patents domestically, in the U.K., and and in the European Union, in 2003 and in 2006, and in other places around the world, such as Japan, Canada, and in the United States as well. Some of the U.K. and European patents have been granted. The first of some of those U.S. patents may be issued in the near future.
The original patent filings were later amended to include new claims. The new claims were much more specifically oriented toward TMBOC and CBOC, whereas the original claims were more generally oriented toward modulated methods. The claims have been modified over the years; this is fairly standard patent practice.
As a result, the original 2003 patent doesn’t necessarily read on a particular signal, but its early filing date has precedence. The claims have been updated and modified, and if the patent office issues those, as a true patent, then the new claims apply. Plenty of big patent battles have been fought over just such issues.
Once the patent is issued, a satellite or receiver manufacturer must assume that it is valid, and has only two responses to make, other than acquiescing to royalty claims. The manufacturer can either say, if building a product, “No, my product does not infringe, and I will prove that it doesn’t.’” The other choice for manufacturers is to go back into the patent office and sue the patent filer (and grantee) in the patent courts and prove that the patent was invalid in the first place that the patentee should not have been granted it.
The United States and others were taken off-guard when the U.K. company Ploughshare, which is owned and controlled by a part of the British MoD called Defense Science and Technology Laboratory (DSTL), started making claims on manufacturers. The DSTL is similar to the U.S. Defense Advance Research Products Agency (DARPA), which is credited with inventing the Internet. If taxpayer money goes into something new and interesting, it is considered in some circles legitimate to file patents on those and attempt to recover taxpayer money through royalties on that taxpayer investment. That concept is not being challenged. Questions as to whether the patents are legitimate are very much in discussion.
Ploughshare has contacted companies, saying, “If you use these signals coming from either the European satellites or the U.S. satellites, we will go after companies using these signals.” There are different patents issued, one by the European Patent Office, applying to most of the EU countries, that applies directly to the TMBOC signal, the E1 OS signal, and possibly also to Europe’s E5 signal, which is E5a and E5b; and there is also a patent for GPS III, the L1C signal.
“If you take the patent that hits TMBOC, and you take the broadest possible interpretation of that patent against receiver companies, it says: if you bring into your antenna and process that signal, whether you use all parts of it or not, for instance if you use the BOC(1,1) and not the BOC(6,1) part — then you infringe the patent. Others argue that if you don’t use both components, you don’t infringe.
“But the claim is written broadly enough that it would apply to any receiver receiving and processing the signal. Nobody says what processing means. The patent says if you receive and process the TMBOC signal, as defined in the prior claim, you infringe the patent.
“There is confusion as to whether that will apply or not apply — some people expect that it doesn’t and some people think that it might. That’s up in the air.”
George Is Getting Upset. Various factions in the United States are upset by and trying to figure out what to do about the impasse. From a government point of view, there are three paths that the U.S. government can follow:
Put pressure on the U.K. diplomatically. That would be up to the State Department to put pressure on the EU or the U.K. in particular. The EU and the continental Europeans are equally furious at the British for doing this, as far as parties in the U.S. understand. This can’t be stated as a fact but is widely understood and thought to be the case. The diplomatic approach has its limits, obviously.
Go into Europe and fight the patents in European patent court and try to prove them invalid, to invalidate the patents. Companies could do the same thing, go into various courts, whether they be U.S. or European or Japanese, and say: “Our receivers don’t infringe,” and then have to prove that to the court; or say “The whole patent should not have been allowed, and I’ll fight the legitimacy of the patent.”
Some believe — and there is controversy and anger on this point — that, just as Galileo’s IOV satellites have the capability to transmit without the BOC(6,1) component, the United States should be able to do that with the GPS III satellites as well. Because if the signal is not there, and if the receivers are therefore not designed to process the signals that are not there, then the patent no longer has any relevance.
“If we are to turn off the BOC(6,1) term for a period of time until the legal or diplomatic or other approaches worked, then we would be able to turn the BOC(6,10) term back on again, and return to the original agreed MBOC and TMBOC signals. That requires some coordination between the United States and Europe, and it requires some work to make that possible in the GPS III satellites, putting a switch in the GPS III satellites to permit the operators to turn that (6,1)BOC on and off. This is being hotly debated.”
Some parties object, stating that L1C is too important a signal to mess with, and this proposal runs the risk of slowing down the program, and/or making it more expensive. They believe strongly that the off/on switch is not the best or most far-sighted option: why should the United States be forced to change its signal design due to an illegitimate patent, and in the end wind up with a less capable system?
It is not publicly known whether the Air Force is or is not looking into that option.
During the week of June 25 there was Working Group-A meeting in Washington D.C. followed by a plenary meeting between the EU and United States. The patent controversy was presumably discussed in some fashion, but whether formally addressed or lurking in the background is unknown at this time.
“There is some naivete around this,” said the magazine’s soure. “It’s a serious threat. People think maybe they’ll only go after the high-end receivers, and maybe the royalties won’t be so bad. Ploughshare is trying to lull people into a false sense of security. The impact of this will be great unless it is defeated.”
“The L1C waveform originally was to have been a pure BOC(1,1) (a 1.023 MHz square wave modulated by a 1.023 MHz spreading code). Negotiations between the U.S. and the European Union (EU) at that time resulted in an agreement that both GPS and Galileo would use a baseline BOC(1,1) signal. However, the EU reserved the right to further optimize their signal within certain bounds. Some of the optimization proposals were known as CBCS and CBCS*. However, in further EU/US discussions it was decided that L1C and the Galileo E1 open service signal should have identically the same spectrum. This was a significant challenge because of different baseline signal structures and existing designs.
“The breakthrough came when [U.S. representative] John Betz proposed what is called MBOC. The MBOC waveform has 10/11th of its power in BOC(1,1) and 1/11th in BOC(6,1). However, L1C and E1 OS achieve this result in very different ways. The Galileo technique is called CBOC. The GPS technique is called TMBOC. Whereas Galileo has a 50/50 power split between pilot and data and includes the BOC(6,1) component in each, GPS includes the BOC(6,1) waveform only in the pilot component by modulating four of every 33 spreading code chips with a 6 MHz square wave and 31 chips with a 1 MHz square wave. With 75 percent of the power in the pilot, the result is 3/4 x 4/33 or 1/11, as required. It is likely the BOC(6,1) signal component will be ignored by consumer-grade GNSS receivers where a narrow RF bandwidth is preferred. Fortunately that is a loss of only 12 percent (0.56 dB) of the L1C pilot power. However, for commercial and professional grade receivers, the extra waveform transitions (wider Gabor bandwidth) can be used to improve code tracking signal-to-noise ratio, and with certain advanced techniques it should be possible to improve multipath mitigation. This final point depends on careful control or calibration of the transmitted code timing and symmetry.”
