GPSWorldTV – Javad Ashjaee, founder and CEO of Javad GNSS – speaking at the ION GNSS Show
Tag: JAVAD GNSS
-
GPSWorldTV – Javad Ashjaee speaking at ION – Part 2 of 5
GPSWorldTV – Javad Ashjaee, founder and CEO of Javad GNSS – speaking at the ION GNSS Show
-
JAVAD Tracks L5 Signals from Indian GAGAN Satellite
JAVAD GNSS has commented on some news that its receivers can track a new L5 signal from the Indian SBAS satellite, GSAT-8, launched on May 20. In a further explanation to GPS World, CEO Javad Ashjaee explained, “All owners of our products can track it. The only thing is that if customers have not updated their firmware for a long time, they should update to recent firmwares released earlier. They need to update their firmware, which is free of charge and is posted on our website. All of our customers with recent firmware versions can track the GAGAN L5 signal.”
An earlier report from CANSPACE that appeared on the GPS World website said, in part, “Although GSAT-8 reportedly carries a dual-frequency transponder, no L5 signals from this satellite have yet been detected by International GNSS Service tracking stations.”
The JAVAD GNSS statement on September 30 said “Report of GPS World that GAGAN PRN127 does not transmit L5 signal is not correct. Our receivers track it. This graph shows code-phase measurements for this signal.” The web page displays this figure:
A check with a University of Bern, Switzerland, report of stations participating in the IGS M-GEX campaign on October 2 found that a number of stations are tracking the L1 signal from GSAT-8 but none are tracking the L5 signal yet due to issues with receiver firmware. However, various stations in the Cooperative Network for GNSS Observation (formerly the Cooperative Network for GIOVE Observation, still abbreviated CONGO), using Javad Triumph receivers, have tracked GAGAN L1 and L5 signals for more than half a year. No detailed analysis of these measurements has been performed so far.
-
JAVAD Asserts Filters Protect GPS L1, L2, L5; GLONASS L1, L2; Galileo L1, L5
Javad Ashjaee, founder and CEO of JAVAD GNSS, has filed a letter with the U.S. Federal Communications Commission (FCC) concerning his company’s development of technical possibilities in GNSS filter designs and components. He states “I hope this will be helpful in establishing realistic guidelines for the characteristics of high-precision GNSS receivers that will be used in critical applications.”
Below is the full text of the letter.
September 7, 2012
The Honorable Julius Genachowski
Chairman
Federal Communications Commission
445 12th Street, S.W.
Washington, D.C. 20554The Honorable Lawrence E. Strickling
Assistant Secretary for Communications and Information
National Telecommunications & Information Administration
United States Department of Commerce
1401 Constitution Avenue, N.W.
Washington, D.C. 20230Dear Chairman Genachowski and Assistant Secretary Strickling:
In this communication I want to inform you of the current status of technical possibilities in GNSS filter designs and components. I hope this will be helpful in establishing realistic guidelines for the characteristics of high precision GNSS receivers that will be used in critical applications.
We have improved our previous L1 filter and have extended the design to include all commercial GNSS bands.

Figure left above is our filter that protects GPS L1, Galileo L1 and GLONASS L1 bands. It brings in all the useful signals intact and rejects out of band signals with the slope of about 12 dB/Mhz. Similarly, Figure right above is our filter that protects GPS L2, GPS L5, GLONASS L2 and Galileo L5 and has slope of about 9 dB/Mhz.
These filters have been extensively tested with five different innovative tests and prove that the filters also improve the performance of GNSS receivers. These extensive innovative tests are embedded in the receivers that we mass-produce today and every user can test their receivers in all environments. These tests are much more extensive than those previously employed by PNT and other organizations. These embedded tests are not only much more extensive, but it takes only a few minutes to perform these by any novice user by clicking some receiver buttons. Compare that to the limited tests by PNT and others that took weeks to perform and needed experts with very expensive equipment in some laboratories to perform.
Attached is our 8-page commercial advertisement that has more details on filters and embedded test features.
These filters not only protect GNSS signals against all LightSquared signals (10L, 10H and 10R handsets) but also from all similar signals that may appear near all commercial GNSS bands in the future. We are proud that our filters help allow better usage of these precious bands, in particular for broadband wireless communication that our country desperately needs.
These filters apply to wideband high precision GNSS receivers and the cost is even less than earlier conventional filters. The case of narrow-band low precision receivers (e.g. Garmin) is much simpler, as has been demonstrated by GPS receivers in more than 300 million cell phones and mobile devices which are not affected by LightSquared signals. The low precision receivers (L1 C/A code only) require filter slopes 10 times less steep than those presented here and do not necessitate additional costs.
In summary, the technology exists today of improved filter design and better performing GNSS receivers and can actually be done at a cost lower than current conventional GNSS receiver filter designs. I trust that the information that I have presented can be used in establishing the performance guidelines and requirements for all GNSS receivers used in critical applications.
I also would like to invite your representatives to ION-2012 GNSS conference where we present details and answer questions at 2:00 PM on September 20.
Regards,

Javad Ashjaee, Ph.D.
CEO, Javad GNSS
San Jose, California
USA -
J-Shield from JAVAD to Counter Interference
JAVAD GNSS announces that it has improved its GNSS protection filters, not only to protect the L1 band against all interferences (including LightSquared 10L, 10H and 10R handset), but to protect against all other interferences which may come in any other GNSS band.
The company calls its improved filter the J-Shield, and states that it will “help make the bands near any GNSS band free for other usages like broadband wireless, which the United States desperately needs to catch up with other nations, as currently the United States is number 16 in the world [in broadband capacity], and to help to create competition to potentially reduce U.S. wireless broadband costs to 1/3 of what they are today.”
CEO and founder Javad Ashjaee will present details on the J-Shield on Thursday, September 20, at the ION-GNSS conference in Nashville, Tennessee, in a talk titled “All about GNSS Interferences and Jammers.”
The talk will cover:
- Where does interference come from?
- How to know, view, quantify and analyze interference.
- How to protect against interferences.
- Implementation of these features in JAVAD GNSS’s mass-produced commercial products.
- Introduction of the J-Shied for all GNSS bands.
The company will also have an exhibit on the ION-GNSS show floor in the Nashville Convention Center, from Wednesday, September 19 to Friday, September 21.
-
Letter to the Editor: Automatic Gain Control, Spoofing
Just for the record: what is reported in “Detecting False Signals With Automatic Gain Control” (April GPS World) is what we introduced a long time ago and is reflected in one of our videos, and implemented in all of our GNSS receivers. AGC information is one of the four ways, and the least significant way, that we show interferences. There is a big difference between showing something in the laboratory and in some receivers, compared with having technology in mass production that everyone can understand and use.
— Javad Ashjaee
JAVAD GNSS, San Jose, CaliforniaAuthor Dennis Akos replies:
I am sure JAVAD receivers work quite well to leverage AGC to flag RFI (it was not the survey-grade model I used for the paper, though). The original Nordnav R30 GPS receiver showed both AGC and the L1 frequency spectrum back in 2004. u-blox has an RFI flag in its receiver, which is based on AGC. Others likely do as well.In any event, AGC detection of RFI (and you could say spoofing) is not new. I coauthored an ION GPS paper with Bastide and others back in 2003 showing how powerful AGC could be to detect interference. In 1997 Per Enge had a student, Awele Ndili, working with the Plessey chipset, who did something similar, checking the AGC for signs of RFI.
So when all the hubbub came up about spoofers a couple years back, I tried to flag the question — why be concerned about this? AGC can tell when more power is coming in the frequency band and thus flag RFI or spoofing is happening. So spoofing is no more of a threat than simple jamming, should one be concerned about it and make a relatively small effort to check for it.
I was quite impressed with the spoofer design Humphreys/Psiaki/Ledvina came up with (“Straight Talk on Anti-Spoofing,” January 2011, and “Assessing the Spoofing Threat,” January 2009). Quite neat, needs very little additional energy with the lift and carry-off approach. But also very hard to leverage for any dynamic case where the victim receiver did not want to be spoofed (spoofing a dynamic receiver with the approach? Doable, but really hard, and would still inject more RF energy). So it left the threat, in my mind, to those who are being monitored and want to spoof their device: very small subset — the fisherman in illegal waters, the prisoner with ankle monitoring. This is the hardest detection case, but I am still fairly confident AGC can work here.
Main motivation for the article: I was troubled that I did not see the need for folks to be up in arms any more about spoofing than plain old jamming.
Again, my premise: in the great majority of cases spoofing is easily detected using technology already in a majority of receivers, making it no worse than jamming, and the harder cases should still be detectable with additional effort/sensors. But it is important for all to remain vigilant, as these AGC-based techniques do need to be implemented/leveraged to avert the spoofing threat — and Humphreys/Psiaki/Ledvina deserve credit for bringing this potential to light. Even with successful spoofing detection it will appear as much less sophisticated jamming, not allowing the receiver to obtain position/time information.
So that is why I worked with the Swedes to try and show this and get that message out. It would have been great to test with one of the more sophisticated jammers (perhaps will have a chance to do so with an upcoming test), but I did not have one, so we just did simple repeater jamming.
I am glad Javad is preaching the same message. It would be great to see him to more widely disseminate that message and put much of these concerns to rest.
Regarding the video: Thanks, Javad. Really some nice features. I need to get a TRIUMPH-VS or two here at Colorado University to work with. Quite curious as to the sensitivity of the AGC. But the receiver has a great feature set!
One quick comment. In the video where you tested the RX with the jammer — I might go back and qualify that indicated you did the test under controlled/allowed conditions. I recall we published an GPS RFI test back about 10 years ago, and we had some official inquires for more details on the testing and why we were broadcasting in the GPS band. No idea how/where you did your testing (assuming 746th Jamfest or similar), but unless you state otherwise, it might bring some unwelcome attention.
-
JAVAD GNSS Tracks Galileo IOV Satellite
On December 12, JAVAD GNSS announced that it has tracked the Galileo in-orbit validation satellite designated PRN-11. It is one of two Galileo satellites launched on October 21.
"An important point is that we tracked it with our units that are already in the market," said Javad Ashjaee, CEO. "This is not a lab tests. Our customers can track it too."
Here are the company's tracking results of PRN-11 for now, plots of pseudorange (in chips), doppler (in Hz), and SNR (relative number):
JAVAD GNSS expects to publish additional results soon.
-
2011 GPS World Leadership Dinner
GPS World’s eighth annual Leadership Dinner took place during ION-GNSS in Portland, and was sponsored by Litton Consulting Group, Sigtem Technology, and JAVAD GNSS. Excerpts from some of the speakers’ remarks appear here, as well as photos from the “You Bet Your System” after-dinner game, the first GNSS Sweepstakes, a group exercise in probabilistic and equestrian studies.

■ Col. Robert Hessin, National Coordination Office for Space-Based PNT.
From my perspective, we have not communicated well enough at a national level a vision for the future of spectrum management and customer access to emerging wireless technologies. The bottom line is, had we planned in 2001 to go deliberately down this path with MSS spectrum, I’m confident we would have found a way to co-exist by 2014.

■ Col. Bernard Gruber, GPS Directorate.
The NPEF test conducted in April was robust and comprehensive, involving over 100 receivers from 24 organizations, spanning military, government, aviation, precision agriculture, automotive, and general use communities. The results demonstrated empirically that the LightSquared terrestrial signals in their original deployment plan interfered with all types of receivers tested. The military results were consistent with results obtained by commercial GPS industry organizations such as Trimble, Garmin, and John Deere through their own independently conducted tests.
We stand ready to work with the NTIA and LightSquared to complete additional testing on the newly proposed deployment plan and receiver filter designs. We are conducting additional tests of cellular and general navigation devices on the LightSquared “Lower 10” MHz terrestrial and handset signals. We are also prepared to test filters proposed as mitigations for high-precision GPS receivers when they become available. As General Shelton stated in his recent congressional testimony, AFSPC remains open to ideas on mitigation strategies that will ensure continued GPS service to billions of users worldwide.

■ Günter Heinrichs, IFEN GmbH.
We in Europe follow very closely — and not without worry — the situation with regard to LightSquared difficulties. It would be very shortsighted for us to say that this problem will not concern us in Europe. Because all of us eventually sit in the same boat. Galileo signals will also be affected by the LightSquared problem — and not only in the USA. Due to the worldwide scarce frequency resources, the times are past that one can look at an application for a certain frequency spectrum in isolation. Decision-makers must sharpen their awareness of the effects their decisions will have on the surroundings, worldwide. In the future, avoidance or minimization of such problems can only be managed by unity and increased coordination of the different responsible stakeholders. We live in a globalized world — this must be taken into account at all future decisions. An early cooperation and coordination between all parties involved at all levels will be essential — also across border.

■ Jim Litton, Litton Consulting.
I want to speak of my pride in our industry, which is confronted with a manmade threat from forces that have support from politically and financially powerful special interests. My former colleagues in NavCom and John Deere have been highly instrumental in this effort. In this crisis, with its unreasonable time-line demands, the industry has pulled together, and competitors have worked with each other to meet the threat with evidence-based, scientifically sound testing and analysis as opposed to the obfuscation, historical distortion, backdoor influence, and fact-denial seemingly characteristic of the ethics of hedge-fund operators. Even some in our industry who are ambivalent about the trade-offs between the integrity of legacy systems and opportunity for new sales have acted with propriety, openness, and respect for the truth. Millions have been spent, and program schedules delayed, to respond in this manner.

■ Greg Turetzky, CSR.
The basics of the problem are that the current rules in the FCC do not provide sufficient protection for GPS. Lightsquared is not the first group to go to the FCC and propose a change to the plan that meets the rules, but still degrades GPS performance. Remember UWB? If we don’t want to have to keep raising our hand and saying, “I know it follows the rules, but we are special,” we should work to change the rules. I would like to see our industry get together and propose any changes that are needed to the FCC. Let’s not forget that this is an international problem. As Tony Pratt reminded me, we could also take this to the ITU. The rules were created to protect one communication system from another. The rules we need would protect a below-the-noise navigation system from a high-power communication system.

■ Javad Ashjaee, JAVAD GNSS.
Spectrum is getting congested, and we cannot assume the luxury that we had can continue any longer. We should not be selfish and expect all others to stay away from us because their smell bothers us! Every GNSS receiver should put in a good filter so that others can coexist near us.
LightSquared is a very nice complement to GNSS. It can provide a nice communication channel for our RTK. If military receivers cannot tolerate LightSquared, how can they survive electronic warfare? If an enemy puts LightSquared-like transmitters in the theater of operation, our military equipment gets affected? Military units with P-code are more sensitive than JAVAD receivers that use encrypted P-code? Starting today, everything JAVAD GNSS ships will be LightSquared-hardened, or eligible for free upgrade later.

Mike Swiek (U.S. GPS Industry Council) and Stuart Riley (Trimble).You Bet Your System
Over dessert and coffee, 150 VIP dinner guests played the ponies: six races, with horses from five GNSS racing stables.

Track stewards Ismael Colomina (Institut de Geomàtica) and Allison Kealy (University of Melbourne) get instructions and prepare to sell tickets.
Mike Shaw (Lockheed Martin) appreciates Jane Wilde’s (European PNT Industry Council) all-in bet.
Tom Hunter (JAVAD GNSS) sees his horse lose by a nose.
Sherman Lo (Stanford), Logan Scott (consultant), and Alan Grant (UK General Lighthouse Authorities) peruse the racing card: “We devised a betting strategy that left us flat broke.”
Compass delegates Yuanxi Yang (China National Administration of GNSS and Applications) and colleague Jing Tang enjoyed the evening — and now plan a GNSS racing event in China — with Fang Sheng (Raytheon).
Gard Ueland (Kongsberg Seatex and Galileo Services) holds a winning ticket, flanked by Grace Gao (Stanford) and Gordon Dale (NovAtel).
Eric Gakstatter counts his winnings as Allison Kealy and Alan Cameron frantically make payouts to Antje Tucci (IFEN GmbH), Rick Hamilton (CGSIC), and Dorota Brzezinska (Ohio State University).
Track stewards Sasha Mitelman (consultant), Fabio Dovis (Politecnico di Torino), and Michael Glutting (JAVAD GNSS).
Mitch Narins (FAA) puts his last dollar down on a bet with Di Qiu (Sigtem).
Col. Bernie Gruber (GPS Directorate) and Ron Hatch (NavCom) celebrate their onscreen winner; trackmaster Sam Pullen (Stanford) at the controls on right.
The racing program. -
How GPS and GLONASS got together — and other recent events
The recent broadcast of the first CDMA signal from the new GLONASS-K satellite culminates a long series of events that began in 1989. A key participant gives a first-hand account of the history of many meetings, formal and informal, that created true interoperability between the two major satellite systems, giving users a modern GNSS in action.
October 18, 1989, the Queen Elizabeth Auditorium in London, around 8:30 am. Unknown to me, two 60-minute periods were about to imprint themselves indelibly on my memory.
I walked up the stairs to the exhibition booth of my company, Ashtech, at The Royal Institute of Navigation conference. My good friend, the late Ann Beatty, met me and asked, “Any news from home?”
I thought it was just a casual customary question, and replied: “Thanks, all OK.” She had a strange look on her face. She continued: “Are all your family really OK?” I replied again: “Thanks, all good.” She then realized that I had no clue about the cataclysmic event that had hit the San Francisco Bay area. She abruptly said, “Don’t you know? The big one came! The big earthquake hit San Francisco!”
Californians know the rumors that when The Big One comes, Nevada will have ocean frontage. Now she was telling me that The Big One came! I rushed to the phone, and the recorded AT&T message said, “All lines to your area are out of service.” It took me another hour to find out that this was not yet The Big One, and that my family was safe. I will never forget these 60 minutes of my life. Never!
Nor will I ever forget the events of the next 60 minutes.
After the stress had settled a bit, a delegation from the Russian Space Agency visited our booth. First they expressed their sympathy regarding the earthquake. Then we discussed GPS technology and its similarities with GLONASS. Both systems were fairly new then, although GPS had started first, with a Block I launch in 1978, followed by GLONASS with a launch in 1982. At the time we met in London, GPS was flying 12 satellites, and GLONASS also had 12 in orbit.
The Russian delegation visited all GPS manufacturers’ booths in the exhibition hall and then gathered in the coffee area for their private discussions. A few hours before the conference closed, they returned to our booth and said, “We want to combine GPS and GLONASS, and you are our first choice.” Simply put, I was fascinated and excited.
After working out visa and travel details, four months later I arrived in Moscow in the cold days of February 1990. It was still the Soviet Union.
I had grown up in Iran where the U.S.S.R. was our neighbor to the north. Remembering the global political landscape of my childhood days, I felt both fascination and fear as my airplane landed at Moscow airport.
Upon meeting the people who greeted me at the airport, my fears disappeared, and my fascination grew stronger.
Our first formal meeting took place in the Institute of Space Device Engineering (ISDE), a division of the Russian Space Agency that was responsible for the GLONASS program. The opening photo shows me with the late Dr. Nikolay Yemelianovich Ivanov, director of the GLONASS program, at that first meeting.
I want to focus a bit on the GLONASS team and applaud them for their efforts. What makes the GLONASS team special is that they worked under much harder political and financial conditions than the GPS or Galileo teams. But still they were able to make the project successful. The Soviet Union and later Russia went through huge political, economic, social, and geographical revolutions, but the GLONASS team managed to keep the satellite navigation program alive and successful.
Galileo’s management, while enjoying much more stability and financial luxury, can certainly appreciate and understand the significance of what the GLONASS team accomplished. Galileo also benefitted from the European integration of 27 countries, while the Soviet Union disintegrated into 15 separate nations.
Despite all their heroic work, individuals on the GLONASS team have received almost no international recognition. At home they went unnoticed, due to their political situations. For example, the highest international recognition that Dr. Ivanov received was that he became a member of the GPS World Advisory Board, which I facilitated. In this article, I want to salute some members that I know and at least keep their names and photos recorded in the GPS World archives.
In the first meeting, everyone recognized and emphasized the great potential of combining GPS and GLONASS for a variety of applications. I became more assured of the deep desires of my hosts to make this happen. They had prepared detailed charts and plans, especially for high-precision applications. They also gave me the GLONASS Interface Control Document (ICD) for the first time.
We signed a cooperation protocol and agreed to explore technical details in our next meeting, which occurred a few months later. There I began to know Dr. Stanislav “Stas” Ulianovich Sila-Navitsky, at that time the chief scientist of Dr. Ivanov’s team. Later he became my vice president in three companies that I founded. He also became my best friend of 19 years, before he passed away on May 7, 2010.
We had several meetings in Moscow and one in Paris in the headquarters of our partner SAGEM.
I have wonderful memories of all the meetings. One meeting in Paris included General Leonid Ivanovich Gusev, the head of ISDE. One evening Stas called my hotel room and asked me to cancel our dinner at a famous French restaurant and instead join them for a “real dinner.” Apparently General Gusev was tired of French food! The real dinner took place in the General’s hotel room, and the menu consisted of dark Russian bread, Russian kielbasa sausage, Russian seledka herring, and an abundance of Russian vodka.
Our first announcement of combining GPS and GLONASS was published in GPS World magazine, in only its second issue, March/April 1990. That year we had a poster banner in our Institute of Navigation exhibition, showing the American flag and the Soviet flag (hammer and sickle) next to each other. My very good friend, Colonel Gaylord Green, the second director of the GPS Joint Program Office, refused to have his picture taken with me in front of that banner. Instead, we stood over to another side of the booth for his photo.
A few months after the Paris meeting, the political process known as perestroika began and caused the Soviet Union to end. Life became extremely difficult for Russians.
I called Stas to discuss the situation. We concluded that we had no choice but to continue the plan on our own if we wanted to combine GPS and GLONASS. I went back to Moscow several times, and in February 1992 officially opened the Moscow office of Ashtech. This office is still operational in Moscow with about 10 percent of the original team. It is now in the process of being purchased by Trimble Navigation. What a turn of events!
In 1996 we introduced the first combined GPS and GLONASS receiver; the product announcement appeared in GPS World, July 1996
Back home in the United States, the situation was different. Supporting GLONASS was an unpatriotic act. The most prominent figures of GPS teased me for wasting my time with GLONASS. The news favored their arguments: the Russian economy was going downhill. In September 1998, the Russian ruble collapsed more than 300 percent within a week. Banks closed. Even Coca Cola was not able to pay its employees in Russia because of bank closures. Many western companies left Russia. During that period, I intentionally stayed longer times in Moscow and managed to pay our employees without a day of delay. Furthermore, a more than three-fold rate change in favor of the dollar made our employees relatively rich, because their salaries were based on the U.S. dollar.
I remained confident that GLONASS would succeed because I had seen the enthusiasm and dedication of GLONASS management and engineers.
My Ashtech partners wanted to take the company public to recoup their investments. They thought Wall Street would negatively view GLONASS and the Russian connection. So my aspiration did not match theirs, and I started Javad Positioning System (JPS) in 1996. About 90 percent of the staff engineers followed me to JPS.
One of John Scully’s vice presidents did to Ashtech what Scully did to Apple. Meanwhile JPS became very successful, as Apple did when Steve Jobs returned.
Subsequent to another event and termination of some obligations and commitments, I started JAVAD GNSS in June 2007. Almost all of the key people followed me again. Our current team has a history of working together for close to 20 years.
In JAVAD GNSS we raised the bar of GPS/GLONASS integration to a higher level and focused in two new directions. The first was to eliminate the problem of GLONASS inter-channel biases, which is inherent to the GLONASS frequency-division multiple access (FDMA) signal structure. The second was to support the opinion of GLONASS engineers who were pushing for a new code-division multiple access (CDMA) signal for GLONASS, similar to the GPS signal.
We resolved the GLONASS inter-channel biases issue around 2009 and announced, “Our GLONASS is as good as GPS.”
On the second front, we worked with the top managements of ISDE and the Information Analysis Center (IAC) of the Russian Space Center to demonstrate the advantages of CDMA for high-precision applications.
Some years ago, Stas had confided in me that the issue of CDMA was nothing new, and had been extensively deliberated at all levels of various GLONASS organizations during the early design phase of the system. The result of all these discussions was that engineers and technical people favored CDMA, but the higher management, mostly influenced by the military organizations, held out for FDMA. The reason for favoring FDMA is still a secret, though some believe that they just wanted to be different from GPS and did not see much advantage in CDMA. Some also believed FDMA gave better jamming protection.
Of course in those very early days, no one imagined using GPS or GLONASS for high-precision applications, and as such truly there was not much difference between CDMA and FDMA. Much later, the notion of using carrier phase of GPS and GLONASS signals for high-precision applications was discovered, and then the advantages of CDMA became relevant, as Dr. Ivanov also hinted in our first meeting.
After we combined GPS and GLONASS, and as a lot of our worldwide users began comparing the two systems, the issue of CDMA versus FDMA again came up for discussion among the GLONASS authorities.
More recently, since 2007, we had several meetings in the offices of ISDE in Moscow, in IAC in Korolev (the Russian Space City), and several in our JAVAD GNSS office in Moscow. Most importantly, we had several meetings in my Moscow apartment, enhanced by Russian vodka and the best Armenian cognac, courtesy of Sergey Revnivykh, head of IAC. All meetings were open and candid, discussing and demonstrating the advantages of CDMA, in support of the ISDE engineers who were reluctant to express their opinion above certain levels.
I also met with the head of the Russian Space Agency, Dr. Anatoly Nikolayevich Perminov, who personally supported and sponsored me in obtaining an extended Russian residency visa. Let me also express my appreciation for receiving the Medal of Honor from the Russian Cosmonauts Federation, along with the official astronaut watch. I don’t understand the reason for receiving a Kalashnikov AK-47 semi-automatic rifle from ISDE for my birthday. I wonder how I can transport it home!
General Anatoly Shilov (deputy director of the Russian Space Center), Dr. Vicheslav Dvorkin (GLONASS deputy general designer), Sergey Revnivykh, Viktor Kosenko (first deputy of chief GLONASS designer) and Sergey Karutin (GLONASS senior scientist) are the new generation of GLONASS leaders who deserve credit for supporting CDMA on GLONASS. Recently, a new GLONASS-K sat-ellite was launched, transmitting an experimental CDMA signal in addition to the legacy signals. Almost immediately, we announced tracking of the new GLONASS-K satellite and its new L3 signal details, hours after it started transmitting. See GPS World archives and our website for details of this signal which seems, in all aspects, as good as GPS.
Another new issue of significant international concern was a new frequency for GLONASS. This issue was more political than technical, and is discussed under the umbrella of interoperability.
In the early days of my frequent travels to Russia, the KGB probably suspected that I was a CIA agent — and the CIA probably suspected that I was a KGB agent! I would not be surprised if both the CIA and KGB monitored every bit of my travels and activities. After some years, the San Francisco airport authorities stopped interrogating me for my activities in Russia any time I came back home. Perhaps because of their deep investigations, I earned the trust and friendship of both sides, and their confidence that I had nothing in mind other than helping to integrate GPS and GLONASS. I was an unofficial member and friend of both U.S. and Russian delegations during the so-called interoperability discussions since 2007, which sometimes touched on the CDMA issue as well.
Some of the most fruitful and friendly discussions between the U.S. and Russian delegations occurred in my apartment in Moscow, after their official meetings. Ken Hodgkins of U.S. State Department; Mike Shaw, director of the National Space-Based Positioning, Navigation, and Timing Coordination Office; David Turner, director of the Center for Space Policy & Strategy; Scott Feairheller of the U.S. Air Force; and Tom Stansell, consultant to the GPS Wing were some of my honored guests.
The new GLONASS frequency discussions are still in progress, and I am proud to host and support both sides the best that I can. Sometimes it is fun to observe that discussions resemble poker games where hands are known to all sides, but players still try to bluff each other! Let’s leave it at that for now.
In May of this year, I had a conversation with General Anatoly Shilov, now second-in-command of the Russian Space Agency, reporting to the first deputy of the minister of defense, General Vladimir Popovkin, who recently replaced Dr. Perminov as head of the Russian Space Center. This is an indication of increased attention and support from the Russian government to its GLONASS program. In our conversation, General Shilov was enthusiastic and optimistic that the GLONASS program will move forward faster.
GLONASS has proven to be a real and reliable complement to GPS. If it were not for the failure of the launch of three GLONASS satellites in December 2010, its constellation would be complete and fully, globally operational today. It will happen soon. Sergey Revnivykh estimates that currently the system has 99.8 percent global coverage.
Today, a truly reliable and fast RTK is not possible without combining GPS and GLONASS satellites.
The most recent testimony to the success of GLONASS comes from the long-time GLONASS opponents who once criticized me for supporting the system. Recently they had to pay a lot of money to acquire the first company that I founded in Moscow, which they believed would never survive.
This year at JAVAD GNSS, I and most of my original employees and GLONASS designers are celebrating our 20th year in Russia, and we are working harder to make the integration of GPS and GLONASS even better.
On May 7, 2010, Stas lost to leukemia. He was not present to witness the successful introduction of our TRIUMPH-VS receivers. My refrigerators in Moscow are full of medicines that he brought for me any time I had a little cold. I miss him a lot, and our team is dedicated to following the path that Stas loved so much.
I want to briefly summarize the current status and the future of GPS and GLONASS from the users’ point of view.
GLONASS now has 24 satellites transmitting FDMA signals in two frequency bands. The failure in the last launch to deploy three more satellites delayed completion of the constellation to the end of 2011. The good thing about GLONASS is that both of its L1 and L2 signals are not encrypted and give better data than GPS P1 and P2 that are encrypted.
GLONASS is considering a plan to add CDMA signals to all satellites and not suffer from inter-channel biases. But it will take about 10 years for this plan to become complete for public use, even if the plan is approved and followed. At JAVAD GNSS, we have already mitigated the effect of GLONASS inter-channel biases to the accuracy of better than 0.2 millimeters. We made GLONASS FDMA the same as GPS CDMA by adding some innovations (patent pending) and enhanced algorithms.
The GPS plan is to add a third frequency signal (called L5) and add an unencrypted signal in L2. But it will take several years to have enough new satellites transmitting these new signals to make them usable for daily work.
In the near term, we have two complete systems, consisting of about 30 GPS and 27 GLONASS satellites. The current non-encrypted GLONASS signals give it an edge over the current GPS encrypted signals, given the fact that we have mitigated the GLONASS FDMA inter-channel biases.
GLONASS is also enhancing its control segment to better monitor GLONASS satellites and improve the system’s clock and orbit parameters. Most of these errors are cancelled in differential and high-precision applications anyway.
Existence of two complete and free systems, GPS and GLONASS, will place some doubt on the future of Galileo, as it will be extremely difficult for Galileo to hope to collect money from users to fund itself. The addition of Galileo, as a third system, will not really add much benefit for users anyway. The only push for deploying Galileo must come from some European military organizations to support their specific interest.
I have been extremely fortunate also to have had the opportunity to work on GPS from its early days, co-pioneering high-precision applications at Trimble Navigation. I owe a lot to Charlie Trimble, who helped me to lift myself up when I sought refuge in the United States in 1981. He taught me GPS as well as dedication in business. I also benefitted from Sunday meetings with Dr. Bradford Parkinson, the first program director of GPS, who was and still is a board member of Trimble Navigation. I am curious to find out how Brad, as a board member, voted in the recent matter of the purchase of Ashtech. Since leaving Trimble, my innovative products at Ashtech, JPS, and JAVAD GNSS have been well documented through the years in GPS World.
My emphasis on GLONASS in this memoir is only to record some histories and recognize GLONASS and some of its pioneers who were often overlooked. GPS is already a well-known, well-established system and is the backbone of GNSS.
As a final note, let me add that our current JAVAD GNSS products have the option of tracking all current and future signals of GPS, GLONASS, QZSS, and Galileo. Yes, Galileo too!
-
The System: QZSS Puts L1C on the Air
QZSS Puts L1C on the Air
JAVAD Receivers Track the First Truly Interoperable Signal
JAVAD GNSS engineers in Moscow have released plots of the C/A, L2C, L5, SAIF, and the new L1C signals broadcast by Japan’s QZSS Michibiki, the first satellite to transmit L1C.
The company stated that all of its current GNSS receivers can track QZSS signals with a software update that is available as an option to purchase.
A new civil signal, L1C is designed to be interoperable among GNSSs. Currently, agreements are in place between the U.S. GPS, Europe’s Galileo, and Japan’s QZSS systems regarding broadcast and use of L1C. The U.S. system is not destined to add the L1C signal until the GPS III block of satellites, still more than three years out.
The SAIF (Submeter-class Augmentation with Integrity Function) signal is a GPS augmentation with information on positioning correction and system health. The QZSS L1-C/A, L2C, L5, and L1C signals are GPS augmentation signals that can be operated reciprocally with positioning signals provided by GPS. The figures supplied by JAVAD GNSS show SNR (top) and code-minus-phase (bottom) plots for L1C.
Plot of QZSS L1C signal, SNR.
Plot of QZSS L1C signal, code minus phase (above).
EC’s Galileo Manager Discusses Progress, Interoperability
Paul Verhoef, the European Commission’s program manager for European Union (EU) satellite navigation programs, discussed current issues at length with GPS World, in a conversation on November 10. He addressed aspects of interoperability with GPS and prospects for further development in that area, the need for an ongoing political commitment by the EU to Galileo, the challenges of financing, the prospects for an 18-satellite constellation (which he dismisses as unrealistic), military considerations for both Galileo and GPS, and the recent uncertainty around Galileo’s Public Regulated Service.
The full conversation is available here. Here are a few extracted quotes:
Interoperability. “We have seen in the process with the U.S. that first of all there has been a quite clear political commitment on both sides, at the highest levels, that interoperability was wanted. Secondly, in the implementation we’ve had a very good working relation with our U.S. colleagues in order to establish that. The advantage that I see is that we have been able at a very early stage to deliver on such an interoperability agreement, that this is clear to industry, it provides for predictability. It allows industry to monitor clearly how the two systems are evolving, and when this interoperability is actually going to be available in the marketplace, and it allows them to time their investments, their R&D, their production, and all the rest.” [ . . . . ]
Challenges. “It is time that Galileo delivers something concrete. We’ve had many years of discussion behind us on whether the system will come, and if it will come, and how it will come, and what it will look like, and all the rest. For my part, I’m very happy to see that in 2011, we plan to launch.
The first four satellites are on the way; they are almost ready. About half the ground infrastructure is currently under implementation, we have every couple of months the opening of another ground station around the world. With this, the system becomes a reality, and I think once the satellite launches will go across television screens in the whole world, people will see that the system is becoming a reality. And I think that is desperately needed in order to give it a sense that things are moving forward. I’m really looking forward to that. That is a piece of good progress we have achieved over the last couple of years.
Constellation. “There is a bit of a discussion for some reason in Europe, for some reason some people seem to think that we could do away with 18 satellites. Well, from me you will hear a solid ‘No.’
“The availability figures for an 18-satellite constellation are around 90 percent on average, which means that for an aggregate total of some six weeks a year you would not receive sufficient views, not have sufficient satellites in sight to actually determine a position. There are going to be sectors like aviation where this is completely unacceptable, and they would never invest in anything if that is what we’re going to do. So my sense is that we will always have a lot of upward pressure in terms of constellation size. Of course it needs to be offset against costs and other considerations, but I think the pressure is always going to be there. It is very premature for people to be trying to take a shortcut, to think, well, maybe we could do with less. Because in the end you would have a constellation with a technical performance which the marketplace is not interested in, and then you would have a real problem.”
Click here for the full discussion, spanning many topics.
GPS Control Upgrade
The U.S. Air Force 2nd Space Operations Squadron is scheduled to release the next software upgrade for the GPS ground system in early December, as part of an ongoing effort to improve and maintain the GPS Operational Control Segment before the next-generation GPS Control Segment is deployed in 2015. The upgrade is expected to be completed in early January 2011. The upgrade does not change the navigation message and should be transparent to GPS users. Tests have shown that the navigation message produced by the new software is identical to that produced by the current ground software. While no anomalies are expected, civilians experiencing any anomalies should contact the Coast Guard Navigation Center at (703) 313-5900.
GLONASS Launch Fails
The Russian Federal Space Agency announced that the December 5 launch of three GLONASS-M satellites ended in failure when the Proton-M rocket’s Block DM upper stage and its three payloads crashed into the Pacific Ocean about 1,500 kilometers (932 miles) northwest of Honolulu. Although an investigation will look into the exact cause of the failure, early unconfirmed reports indicate a software error. According to the Russian News Agency RIA Novosti, incorrect calculations were loaded into the rocket’s onboard computers.
Compass Settles, Moves
The Beidou/Compass G4 satellite launched on October 31 achieved geostationary orbit by November 6. The satellite is positioned at about 160 degrees east longitude. G4 is the furthest east of the operational Beidou geostationary satellites. Meanwhile, the orbital location of the Beidou 1A satellite has been changed.
On or about October 27, as indicated by NORAD tracking data, the satellite underwent a significant delta-V, raising its orbit by about 200 kilometers. Its orbit had been slightly drifting for a few weeks before the maneuver, and there was speculation that the satellite had been placed in a disposal or graveyard orbit. However, on November 24 a second delta-V was observed that returned the satellite to the geostationary belt.
The two maneuvers placed the satellite at a new location at about 60 degrees east longitude — the furthest west of any of the Beidou satellites. The satellite may eventually end up at 58.75 degrees east, one of the Beidou orbital slots registered with the International Telecommunication Union.
The geostationary satellite, the first for the demonstration regional Beidou system or Beidou-1, was launched on October 30, 2000, and positioned at 140 degrees east longitude. Following several years of use, there were unofficial reports that the satellite was no longer functional. However, station-keeping was maintained, implying some usefulness of the satellite. It remains unclear how functional the satellite is and whether it is still useful for the Beidou-1 demonstration system.




