GPS World

Tag: Galileo IOV

  • Next Galileo Satellite Reaches French Guiana Launch Site

    The third Galileo In-Orbit Validation flight model satellite being unloaded from its Antonov 124-100 transport aircraft at Cayenne Airport in French Guiana on August 7.
    The third Galileo In-Orbit Validation flight model satellite being unloaded from its Antonov 124-100 transport aircraft at Cayenne Airport in French Guiana on August 7.

    The next Galileo navigation satellite has touched down at Europe’s Spaceport in French Guiana, to begin preparations for its launch in October, reports the European Space Agency. Cocooned within a protective, air-conditioned container, the satellite left the Thales Alenia Space Italy plant in Rome on Monday evening for nearby Fiumicino Airport.

    At 23:15 CEST it boarded an Antonov 124-100 aircraft for its overnight flight across the Atlantic, stopping in Tenerife at 03:50 CEST for refuelling.
    The satellite touched down on Tuesday, August 7, in French Guiana’s Cayenne Airport at 07:55 local time (12:55 CEST). It was accompanied by a four-person team from Thales, plus one representative each from Astrium and ESA, as well as all the specialized test and support equipment that will be needed during the launch preparations. The satellite was then moved onto a lorry for transport to the Guiana Space Centre, for subsequent removal from its container.

    These third and fourth Galileo In-Orbit Validation (IOV) satellites are due to be launched aboard a Soyuz ST-B vehicle in October. These new satellites will join the first two Galileo satellites — launched last year — in medium-Earth orbit at 23,222 kilometer. This will mark a significant step in Europe’s program because it will complete the deployment of infrastructure required for the IOV phase and will allow for the first time a computation of on-ground position based solely on Galileo satellites, ESA said.

    The IOV phase is being followed by the deployment of additional satellites and ground segment as required to achieve the Full Operational Capability, leading to provision of services. 
The first 22 of these Final Operational Capability satellites are being built by OHB in Germany, responsible for the platforms and final satellite integration, and UK-based Surrey Satellite Technology Ltd., producing the payloads.

    The first four Galileo IOV satellites have been built by a consortium led by EADS Astrium, Germany, with Astrium producing the platforms and Astrium UK responsible for the payloads.

  • NavSAS Group Acquires, Tracks Second Galileo IOV Satellite

    On January 17, the E1 signal of the Galileo Flight Model 2 satellite (FM2, also known as GSAT0102) was successfully acquired and tracked by the researchers of the Navigation, Signal Analysis and Simulation (NavSAS) group (Politecnico di Torino / Istituto Superiore Mario Boella) for the first time at 11:54:10 CET (10:54:10 UTC).

    This signal has been received at the Istituto Superiore Mario Boella (ISMB) premises (located in Torino, Italy, latitude = 45°03'54.99" N, longitude = 7°39'32.29" E, height = 311.97 meters) with a non-directive GNSS antenna, a commercial narrowband E1 RF front-end, and the N-GENE receiver, a fully software receiver developed by the NavSAS researchers.

    The FM2 satellite currently broadcast a Galileo Open Service signal on E1 band using the Code Number 12 of the Galileo Interface Control Document (ICD). It is the second of the two Galileo In-Orbit Validation (IOV) satellites launched on October 21, 2011. The first IOV satellite — the Galileo-ProtoFlight Model (PFM) spacecraft — was received by NavSAS researchers for the first time on December 12.

    Both the PFM and the FM2 satellites were in view January 17, and their E1 signals have been successfully received and processed.

    Figure 1 and 2 show the orbits of the two Galileo satellites at the moment of the signal acquisition. These screenshots have been produced by a free software tool (Orbitron, by Sebastian Stoff). In Figure 1 the two satellites, denoted as GALILEO-PFM GALILEO-FM2, are visible. Figure 2 shows a detailed skyplot computed in Torino, Italy.


    Figure 1. Galileo IOV satellite orbits at the moment of the signal acquisition.


    Figure 2. Skyplot of Galileo IOV satellite orbits at the moment of the signal acquisition.
     

    The Galileo FM2 satellite signal (PRN 12) has been successfully acquired for the first time at 11:54:10 and the first acquisition and tracking results are reported from Figures 3 to Figure 6. It can be noticed that the satellite signal was received with a C/N0 of approximately 46.4 dBHz and a Doppler frequency shift equal to -2595 Hz.


    Figure 3. Search space of the successful acquisition of the Galileo FM2 satellite (PRN 12).


    Figure 4. Zoom on the peak obtained acquiring the Galileo FM2 satellite (PRN 12).


    Figure 5. Estimated C/N0 and correlation values obtained tracking the PRN 12.
     


    Figure 6. Estimated Doppler values obtained tracking the PRN 12.
     

    Also, the Galileo PFM satellite was in view on January 17, and the signals from both satellites have been measured and compared by the NavSAS researchers. Figure 7 shows the elevation patterns of PFM and FM2 satellites as obtained from prediction visibilities based on NORAD tracking information (two-line elements of Galileo satellites downloaded on January 17). Figure 8 shows both the estimated Doppler and C/N0 profiles obtained from multiple measurements performed on the same time interval: their trends agree with the satellite elevations shown in Figure 7.


    Figure 7. Elevation pattern versus time of the PFM and FM2 satellites over Torino on January 17.


    Figure 8. Estimated Doppler and C/N0 profiles along multiple measurements performed on January 17.

    As a final step, the demodulation of the E1b data channel has also been performed, checking the navigation messages for both the satellites. It has been noticed that, at the moment, the navigation messages present only two types of page: reserved (word type field with value 63) and type 0 (spare). Type 0 words have valid Week Number and Time Of Week fields. On the other hand, both the satellites broadcast a valid secondary code on their E1c pilot channels, compliant with the Galileo ICD.

  • Second Galileo IOV Satellite Transmitting Signals

    News courtesy of CANSPACE Listserv.

     

    On Monday, 16 January, at about 02:18 UTC, the second of the two Galileo In-Orbit Validation (IOV) satellites, FM2 (Flight Model 2) also known as GSAT0102, started transmitting navigation signals on the L1/E1 frequency using the E12 ranging code, according to tracking reports from the COoperative Network for GIOVE Observation (CONGO).

    FM2 was launched together with PFM, the ProtoFlight Model (GSAT0101), on October 21, 2011. PFM started transmitting E1 signals on December  10, 2011, and E5 signals on December 14, according to CONGO network tracking reports. Subsequently, ESA confirmed that the E6 transmitter was powered up the weekend before Christmas.

    CONGO is a global network of 19 tracking stations established by the German Space Operations Center (DLR/GSOC) and the German Federal Agency for Cartography and Geodesy (BKG) in cooperation with several agencies including Technische Universitaet Muenchen.

  • First Galileo IOV Satellite Producing Full Spectrum of Signals

    Galileo team at Redu receiving signals.

    Europe’s first Galileo satellite appears to be functioning as expected, transmitting test signals received by the European Space Agency’s ground station in Redu, Belgium, across the whole of its assigned radio spectrum, ESA reports.
     
    The first two Galileo satellites were launched by Soyuz from Europe’s Spaceport in French Guiana on October 21. They are currently in the midst of a rigorous campaign to check that their highly sophisticated navigation payloads are operating as planned, unaffected by the strains of launch.

    Testing is centered on the first Galileo satellite for now, and expected to progress to the second satellite early in the new year.

    The Galileo system offers various groups of users a total of 10 different modulated signals across three spectral bands, known as E1, E5 and E6. The weekend before Christmas, all Galileo signals were activated simultaneously across these bands for the first time, following the switch-on and outgassing — warming up to vent potentially harmful vapours — of power amplifiers in the remaining E6 band.

    The signals were received by Galileo Test User Receivers deployed at the Redu ground station, within Belgium’s Ardennes forest, as well as by identical receivers at ESA’s Navigation Laboratory, in ESA’s ESTEC technical centre in Noordwijk, the Netherlands.

    These test receivers work in the same way as operational receivers will once Galileo begins its initial services in 2014. They are capable of processing the Open Service, Commercial Service and Safety-of-Life Service signals from the Galileo constellation.
     

    Galileo combines multi-frequency signals with the most accurate atomic clock ever flown in space for navigation, accurate to one second in three million years, ESA said. Its signals should open up a large number of commercial applications by combining this accuracy with the increased reliability of dual- or triple-frequency measurements. Receiver developers can choose among the variety of Galileo signals on offer to meet the needs of their customers in the most efficient way. They can also combine the processing of Galileo signals with GPS or Russian GLONASS signals to offer more robust positioning information in challenging environments such as city center urban canyons.

    First Galileo triple band signals. (Click to enlarge.)
     

  • GMV Tracks the First Galileo IOV Satellite

    GMV, one of the world’s leading companies in satellite navigation systems, announced the tracking of both data and pilot channels of Galileo first satellite signal with its own line of GNSS receiver products.
     
    The first two Galileo satellites were launched from Kouru Spaceport in French Guiana on October 21st and are now in in-orbit test campaign. The Galileo PRN 11 started transmitting the first navigation signal last Saturday.
     
    GMV has been involved in GNSS for the last 25 years and today GMV’s GNSS team includes more than 120 highly specialized engineers, some having more than 15 years experience in the GNSS field. GMV plays a critical role in the ongoing development of Europe’s GNSS strategy, being a key partner in the EGNOS and Galileo programmes.
     
    GMV has developed its own GNSS software receiver products: SRX-10 on GPS, which has been optimized for the urban environment, NUSAR for GPS L1 and Galileo E1 and its own L1 front end. This experience has been applied, even previously to the development of the receivers, to many studies on receiver performances under very diverse signal conditions and designs, namely by processing the GIOVE satellites signal.
     
    Supported by its line of GNSS receiver products, GMV now presents its results on the first Galileo signals on both data (E1-B) and pilot (E1-C) channels of the Galileo PRN 11 satellite.

  • E1 and E5 Galileo IOV Signals: Report from U. Calgary

    This article gives a brief overview of the acquisition and tracking of Galileo IOV signals received from the GSAT0101 satellite on the morning of December 15. Researchers in the PLAN Group successfully recorded E1 and E5 data using a single dual-channel front-end and subsequently acquired and tracked E1 B/C, E5a and E5b signals using the PLAN Group GSNRx software GNSS receiver.  

    A little over seven weeks after launch, one of the two Galileo IOV satellites began to transmit on the E1 band. To the delight of eagerly waiting researchers worldwide, Galileo-PFM (GSAT0101) broke radio silence on December 10, 2011. Within hours the community was alive with reports of successful acquisition and tracking of the E1 B/C signals. Four days later the E5 signal was also activated. In the early hours of the morning of the 15th of December researchers gathered in the PLAN Group at the University of Calgary and observed the sky filled with broadcasting satellites from three GNSS. Using a dual channel front-end designed in-house, a Novatel GPS-703-GGG antenna and a laptop computer, IF data was collected to examine these new signals. This data was processed by GSNRx, a reconfigurable a multi-system, multi-frequency software receiver developed by the PLAN Group [1]. The equipment used to acquire and process the data is shown in Figure 1.

    Figure 1 The equipment used to acquire and process the Galileo-PFM signals included an in-house dual frequency front-end, a 10 MHz OCXO, a Novatel GPS-703-GGG antenna and a standard laptop computer running the GSNRx software receiver.

    At approximately 03:20 MST (UTC – 7:00) more than 20 GNSS satellites were visible from a rooftop mounted antenna. Having reconfigured the front-end to accommodate the E5 band, IF data was collected which included Galileo E1 B/C and E5 A/B, GIOVE-B E1 B/C and E5a, GPS L1 C/A and L5, and GLONASS L1 C/A. Following some last minute modifications to GSNRx to include the Galileo E5b signals, the samples were processed, simultaneously tracking GPS and Galileo on both the L1/E1 and L5/E5 frequencies and GLONASS on L1. A screenshot of the receiver in operation is shown in Figure 2.

    Figure 2 Screenshot of GSNRx while processing the Galileo PFM signals

    The versatility of GSNRx had been exploited in the past when new signals were brought online. In particular, the modular design adapted for PLAN’s software receiver had been utilized to quickly add new signals and new signal processing techniques. Once again this flexibility was drawn upon to facilitate the last-minute addition of the E5b I/Q signals (that very night) and to enable the stand-alone tracking of each signal component. By the same means, of course, this structure could be easily manipulated to enable composite tracking of data/pilot signal pairs or even facilitate vector tracking of all signals in view.

    A subset of the raw correlator values for the E1 B, E1 C, E5a I and E5a Q signals are shown in Figure 3, (note that the E1 C values have been offset by -2.0×105 for clarity). A data-rate of 250 symbol/s is clearly visible on the E1 B and E5b signals while a 50 symbol/s stream can be observed on the E5a I signal. The 25 chip secondary code is also evident on E1 C at a rate of 250 chip/s.

     

     

    Figure 3 Raw Correlator Values for the E1 B/C, E5aI/Q and E5bI/Q signals. The bit periods can be clearly seen on E1B, E5aI and E5bI. The secondary code can be observed on E1C while the pilot signal can be seen on singals E5aQ and E5bQ.

    All six components of the Galileo-PFM signals shown above (transmitted on PRN 11) were tracked independently and their signal modulations were found to agree with the Galileo Open Service ICD [2]. A trace of the measured carrier-to-noise floor ratios for the Galileo signals is shown in Figure 4. As indicated by the ICD, the E5b signals were observed at 2 dB lower power than the E1 B and C signals. The E5a signals, however, were expected to be received at the same power as E5b and yet were observed at approximately 4 dB lower power. This is believed to be a combination of the antenna and IF filtering within the front-end as the E5a center frequency is located relatively near the pass-band edge of both.  This front-end was initially designed for 40 MHz bandwidth, but used in this experiment at 50 MHz, as will be discussed later.

    Figure 4 Measured C/N0 for Galileo-PFM Signals

    The software receiver was once again reconfigured, this time to produce signal correlator values spaced along a delay of approximately 700 m and 70 m for the E1 A/B and E5 A/B signals, respectively, such that the cross-correlation of the received and local-replica PRN sequences could be examined. The signals were tracked for 10 seconds and the 1 ms correlator values averaged, to produce estimates of the code cross-correlation function. The characteristic ripple of the CBOC modulation on E1 B/C can be seen in Figure 5 (left), particularly on the right-most ascending feature of the envelope. Likewise, the alt-BOC cross-correlation of E5a Q in Figure 5 (right) is as expected. It is noted that the E5a I signal has suffered some distortion due to the filtering effects mentioned above.

    Figure 5 Measured cross-correlation functions for the Galileo PFM E1 B and C signals (left) and E5a I and E5b I signals (right).

    The PLAN group’s front-end is a highly flexible GNSS signal capture tool ideally suited for use with the GSNRx software receiver. The front-end, photographed in Figure 6, allows software reconfiguration of oscillator source (onboard, or external), antenna bias voltage, sampling rate, and IF bandwidth in addition to other low level control options making it highly adaptable.   Furthermore, the center frequency, and filter bandwidth of each of the two hardware channels is independently configurable between 1150 – 2000 MHz, and between 4—40 MHz bandwidth (single sided) respectively.

    Figure 6: PLAN group two-channel reconfigurable front-end with main system blocks labeled.  The external clock and GNSS antenna SMA connectors are along the right edge, while the data interface is via mini-USB on the opposite side of the front-end.

    Typically the front-end is configured to collect dual bands of 40 MHz two-sided bandwidth in order to cover the L1 and L2 transmission bands of both GPS and GLONASS as is shown in the right and central blocks within Figure 7.  To allow the capture of E5a/E5b, the front-end configuration software was used to move the center frequency of channel B from 1237 MHz to 1192 MHz, the bandwidth of channel B from 33 MHz to 50 MHz, and to increase the sampling rate of both channels from 40 to 50 Ms/s.

    Figure 7: Front-end channel A and channel B typically configured to capture GPS and GLONASS L1+L2, but reconfigured here to allow capture of Galileo IOV E5a+E5b signal in lieu of L2 band.

    While each of the E5a and E5b signals have main lobe widths of 20.46 MHz (two sided), the composite E5 signal covers 50 MHz of spectrum, overlaying both the current GPS L5 signal at 1176, and the future GLONASS L3 signal near 1207 MHz.  In order to demonstrate the capabilities of the GSNRx software receiver as an L5/E5 + L1/E1 system, it was desirable to capture the new IOV signals in their entirety.

    The Galileo PFM satellite was observed from the Calgary Laboratory on the E1 link since the 12th of December at approximately 08:00 hrs and on the E5 link since the 14th of December at approximately 18:00 hrs. The last successful acquisition of the satellite on either E1 or E5 was at 03:20 hrs on the 15th of December and indicated a Doppler of approximately +2.3 kHz at E1. This figure is compatible with a reported elevation of approximately 40 degrees and rising, as reported by a number of software packages operating on a TLE [3]. Researchers recorded IF data once again at 03:55 on the 15th of December but failed to acquire any of the Galileo-PFM signals, suggesting the satellite may temporarily have ceased transmission.

    References
    Petovello, M. G., and C. O’Driscoll, G. Lachapelle, D. Borio and H. Murtaza (2008), “Architecture and Benefits of an Advanced GNSS Software Receiver,” Journal of Global Positioning Systems, vol. 7, no. 2, pp. 156-168.
    Galileo Project Office. Galileo OS SIS ICD. http://ec.europa.eu/…/galileo/files/galileo-os-sis-icd-issue1-revision1_en [Accessed: 15 December 2011].
    NORAD Two-Line Element Sets.  http://celestrak.com/NORAD/elements/, [Accessed: 15 December 2011].
     

  • 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.

  • Galileo IOV Satellites Reach Operating Orbits

    News from CANSPACE Listserv.

    An announcement from ESA on November 4 stated "Europe’s first two Galileo IOV satellites have reached their final operating orbits, opening the way for activating and testing their navigation payloads." But, based on NORAD/JSpOC tracking of the satellites, it seems that the final orbits were achieved only a day or so ago.

    The plot above (and linked here) shows the mean motion (mm) of the PFM and FM2 satellites since launch. As evidenced by the lengthy gaps in the mm history, it is clear that NORAD/JSpOC sometimes has difficulty in reacquiring satellites after delta-V manoeuvres. We do know, however, that both satellites have appeared to reach their final orbits sometime between November 19 and 23. The mm values are now very close to the value 1.7046556 orbits per day derived from the mean semimajor axis of the Galileo constellation as given in the Galileo Open Service Signal-In-Space Interface Control Document: 29601.297 km.

    The arguments of latitude of the two satellites, essentially in the same orbit plane, are now 40 degrees apart as intended. There have not been any public reports that navigation signals from the satellites have yet been switched on.

  • The Good, the Bad, and the Really Ugly

    The Good, the Bad, and the Really Ugly

    The Good

    This month there is good news — great news, actually — where GPS and PNT (Position, Navigation and Timing) systems are concerned. On October 22, a Russian Soyuz rocket placed in orbit the first two validation satellites, built by EADS Astrium Germany, in the Galileo PNT constellation after making its maiden launch from Kourou. Don’t confuse these recent satellites with the earlier experimental satellites, GIOVE-A launched in 2005 followed by GIOVE-B launched in 2008. These initial satellites served to preserve the Galileo ITU frequency filings and test the first-ever space borne Hydrogen Maser atomic clock, which by all accounts is proving to be extremely accurate.

    21102011-_SCO3184-W-1
    The Soyuz launch of two Galileo IOV satellites.

    While it is interesting the Europeans decided on a Russian vehicle for the first Galileo dual launch, the U.S. recently pinned its hopes on a European Ariane Five (pictured at right) to launch a commercially hosted U.S. government payload known, appropriately enough, as the “Commercially Hosted Infrared Payload” or CHIRP sensor, which was specifically developed by the U.S. government as a test payload to test both the payload sensor capability and the commercially hosted options for sensor payloads in GEO. The CHIRP sensor features a fixed telescope that can view one quarter of the Earth from geosynchronous orbit. So it appears that hosted payloads and international launch cooperation efforts are growing and are apparently working successfully.

    The two newest Galileo satellites deployed four hours after the Soyuz rocket lifted off from Kourou, in French Guiana.

    The Soyuz launched the first two of four validation Galileo satellites designed to validate the Galileo concept by testing both space and ground operations. Two additional validation satellites are scheduled to follow in the summer of 2012. Once the In-Orbit Validation (IOV) phase is completed, an additional 12 satellites will be launched to reach an Initial Operational Capability (IOC) of 16 satellites sometime in 2014, and that date looks extremely doubtful.

    According to our own Richard Langley, “During initial operations, the [Galileo] satellites will be controlled by a joint ESA and CNES French space agency team in Toulouse, France. Once that week-long phase ends, the satellites will be handed over to the Oberpfaffenhofen Galileo Control Centre near Munich, [Germany], operated by the DLR German Aerospace Center, which will be responsible for routine operations. Operating the satellite payloads to provide navigation services will be the task of the Fucino Control Centre, near Rome, operated by Telespazio.”

    Now, does that sound like a confusing and expensive ground support system? Everybody and every country insist on their piece of the pie, regardless of efficiency and continuity of operations. Who knows this might work; only time will tell.

    The approximately $7.5 billion Galileo constellation will eventually, hopefully, comprise a retinue of 27 operational satellites with three on orbit spares by 2020.

    The PNT business is obviously good for the Russian launch business. Russia successfully launched a GLONASS-K1 test satellite back in February, followed by three GLONASS-M satellites this month into a constellation that finally, after 29 years, accounts for 23 operational and three hopefully soon-to-be operational satellites. The first operational GLONASS-K1 is not scheduled to be launched until sometime early in 2012. GLONASS satellites have historically proven to be fragile affairs with extremely short lifespans; it remains to see how long this number and capability will be maintained. Hopefully the new K1 and M generation GLONASS satellites have resolved many of the longevity issues. Only time will tell when and if the Russian GLONASS will ever regain Full Operational Capability (FOC), which requires 24 simultaneously operating satellites. The Russians were briefly FOC in December 1995, but unfortunately only for a few months. The word “simultaneous” is important as Russian scientisst frequently state they have 25 or 27 GLONASS satellites in orbit, but unfortunately only 22 or 23 of them are operating. But it is possible, miracles still happen, that by the time you read this GLONASS may actually legitimately have achieved FOC once again.

    Now on the Boeing IIF side of the house, more good news as it was announced this week that the second IIF satellite (IIF-2), which has been operational with an elevated signal strength for several months, now has its signals back within the specified signal strength and is good to go. GPS IIF-3 was originally scheduled for launch this coming summer, but the latest launch schedules show the launch in September 2012, about 11 months from now. With 30+ operational GPS satellites on orbit plus residuals, hopefully this will be soon enough.

    Apple & GLONASS

    Always betting on the come, we now know that the late genius Steve Jobs directed his enterprising engineers to include GLONASS PNT software in the latest iPhone 4S; the latest version iPhone that sold 1.3 million units in one day. This effectively gives the iPhone 55 potential satellites to choose from for PNT information as well as the Wi-Fi, cellular tower, and SkyHook Wireless PNT information. With the addition of the GLONASS PNT resources, the iPhone may now well be the most versatile and capable general-purpose PNT platform that exists today. Is that a sad commentary for other GPS and mobile phone providers, a marketing challenge, or merely a positive sign of the technologically advanced times in which we live? It may in fact simply be a true reflection of the capabilities of the most recognized and profitable corporation in the world today. Apple is doing many things right, and one of them is listening to the consumer and giving them more than they expect. Consequently, customers are loyal and Apple Inc. surpassed Microsoft in market capitalization in 2010, and in 2011 became the most valuable consumer-facing brand in the world. Apple is a company Fortune magazine has named the most admired company in the United States for the last three years running. Apple iPhones and numerous PNT applications are certainly in use by thousands of our warfighters in and out of theater. Interesting, to say the least, plus food for thought and a topic for a future column.

    The Bad

    The bad news not surprisingly comes via the U.S. government and no, it is not about LightSquared, because that situation continues to be worse than merely bad. No, the bad news comes in the form of a recently released but curiously out-of-date publication concerning GPS by the Congressional Budget Office (CBO).  In late October 2011, the CBO released a publication entitled The Global Positioning System for Military Users: Current Modernization Plans and Alternatives.

    I was unfortunate enough to receive both a soft and hard copy; and to make matters worse I don’t own a parakeet. The good news is we do have several fireplaces in our home and winter is rapidly approaching. Truthfully, the report is that bad and out of date, but at least it is boring and long. Fortunately hardly anyone is likely to actually endure the pain and suffering required to read through the entire document. However if you are a masochist and/or suffering from acute insomnia I highly recommend this CBO report as a possible cure. Some of you might justifiably complain I have no business giving medical advice because I am not a medical subject matter expert (SME) and I wholeheartedly agree, just as I agree that the CBO is definitely not a GPS SME and should stay with what they do know. Whatever that is.

    I can assure you when and if the military needs advice concerning future GPS operations and options the last place they will or should turn is to the CBO. For example, the preface of the document clearly states, “In keeping with CBO’s mandate to provide objective, impartial analysis, this study makes no recommendations.” Contrary to what you may think this is actually good news, since now we don’t have to waste valuable time dealing with flawed recommendations; garbage in, garbage out. Now if only the analysis were impartial or objective, which it is decidedly not. I would even settle for accurate, which it is definitely not. The information in this document is in some cases, as in M-Code satellites, erroneous and confusing; it is out-of-date where the GPS III nomenclature and options are concerned, especially the spot-beam; and it is always misleading concerning objectivity that presents facts not in evidence. There is so much erroneous and misleading information in this report that I sincerely hope no one else reads it, especially our military users.

    Seriously, all kidding aside, if you must read this document, consider it to be retitled as: The Global Positioning System for Military Users: Outdated Modernization Plans and Alternatives Not Currently Being Considered by the DoD.

    Against my better judgment I am including a link to the CBO document for those of you who practice self-flagellation. I truly regret the number of tree lifespans cut short to produce this confusing, misleading, out-of-date, and totally unnecessary document. Sometime I will tell you how I really feel.

    The Really Ugly

    The “really ugly,” as you have probably surmised by now, refers to LightSquared and the clueless FCC. Can you believe we have been dealing with this fiasco for more than 12 months? You are probably tired of it all, I know I am, but I see that as a true danger signal. The situation is very clear technically, the LightSquared signals, both from the terrestrial transmitters and receivers, will significantly impair and jam GPS signals to the detriment of all GPS users. Of course the political and business ineptness continues apace so who knows how long we will be dealing with this issue, but we cannot afford to let down our guard. Although this is exactly what LightSquared, the FCC, and the current administration, in an upcoming Presidential election year, obviously hope will happen. They hope we will all just get tired of dealing or even hearing about this LightSquared mess and then they win by default. We all have more important matters demanding our attention, right? Of course we cannot and are not going to allow that to happen. We will continue to use LightSquared as a verb when necessary and keep the real facts front and center, right here in GPS World, until all aspects are resolved. You can count on it.

    Until next time, happy navigating.

     

  • Galileo Satellites Handed over to Control Center in Germany

    Europe’s first two Galileo satellites have reached their final operating orbits, opening the way for activating and testing their navigation payloads, reports the European Space Agency (ESA).
     
    Marking the formal end of their LEOP Launch and Early Operations Phase, control of the satellites was passed on November 3 from the CNES French space agency center in Toulouse to the Galileo Control Centre in Oberpfaffenhofen in Germany.

    Oberfaffenhofen, operated by the German Aerospace Center DLR, will be in charge of the satellites' command and control for the whole of their 12-year operating lives, ESA said.

    The two Galileo satellites were launched by Soyuz from French Guiana on 21 October. Three hours and 49 minutes after launch, their Fregat-MT upper stage carried them into their planned 23 222 km orbit, where they were released simultaneously.

  • The System: Galileo IOV Satellites Now in Orbit

    The first two satellites for Europe’s Galileo global navigation satellite system were lofted into orbit October 21 by the first Russian Soyuz vehicle ever launched from Europe’s Spaceport in French Guiana in a milestone mission, reports the European Space Agency (ESA).

    The launch occurred one day after initially scheduled to resolve a problem with the ground-support fueling system.

    The Soyuz VS01 flight, operated by Arianespace, started with liftoff from the new launch complex in French Guiana at 10:30 UTC on October 21. All of the Soyuz stages performed as expected and the Fregat-MT upper stage released the Galileo satellites into their target orbit at 23,222 kilometers altitude, 3 hours 49 minutes after liftoff.

    The two Galileo satellites are part of the In-Orbit Validation (IOV) phase that will see the Galileo system’s space, ground, and user segments extensively tested. During initial operations, the satellites will be controlled by a joint ESA and CNES French space agency team in Toulouse, France. Once that week-long phase ends, the satellites will be handed over to the Ober-pfaffenhofen Galileo Control Centre near Munich, operated by the DLR German Aerospace Center, which will be responsible for routine operations. Operating the satellite payloads to provide navigation services will be the task of the Fucino Control Centre, near Rome, operated by Telespazio.

    The next two Galileo satellites, completing the IOV quartet, are scheduled for launch in summer 2012. Together, alll four are intended to prove the design of the Galileo system in advance of the other 26 satellites.

    These first four satellites, built by a consortium led by EADS Astrium Germany, will form the operational nucleus of the full Galileo satnav constellation. According to ESA, the satellites combine the best atomic clock ever flown for navigation — accurate to one second in three million years — with a powerful transmitter to broadcast precise navigation data worldwide.


    Artist’s depiction of a Galileo satellites being ejected from the dispenser.

    Second IIF Good Now

    The second GPS Block IIF satellite, SVN63/PRN01, launched in mid-July, was finally set healthy on October 14. The delay in bringing the satellite into service was due, in part, to extended testing of the cesium atomic frequency standard (AFS) on the satellite.
    GPS IIF satellites carry three AFSs: one cesium and two rubidiums. The performance of the cesium AFS, independently confirmed, was poor. A switch to one of the rubidium AFSs took place on October 5.

    U.S. Agencies Speak Out on LightSquared; Others Hide Their Cards

    The U.S. House of Representatives Committee on Science, Space, and Technology has released some of the impact statements provided by federal agencies to the National Telecommunications and Information Administration (NTIA). The reports reveal deep concerns about and opposition to the LightSquared proposal, and detail cost estimates and other adverse impacts to government-wide operations should it go forward.

    The NTIA itself has refused to make these agency reports public, rebuffing a Freedom of Information Act (FOIA) request by GPS World magazine and, so far, giving the same response to congressional committees on both the House and Senate side.

    Missing in Action. The House Committee does not yet have access to all the agency statements; still missing are those from:

    • the Department of Homeland Security,
    • the Department of Commerce,
    • the National Oceanic and Atmospheric Administration,
    • the National Institutes of Standards and Technology.

    The House committee has written to those departments asking for their reports; GPS World has also filed further FOIA requests specifically with those agencies. The Department of Defense impact statement is presumed to be classified.

    Seventy-Two Billion. The Federal Aviation Administration (FAA) impact statement is the strongest statement of those provided so far to the House committee. It asserts, among many other findings, that the LightSquared proposal would cost the aviation community at least $72 billion, preclude elimination/reduction of an estimated 794 air-traffic fatalities over the next 10 years, set back planned air-traffic safety and efficiency measures by that same period, affect U.S. leadership in aviation, and damage the international market for U.S. satellite technology.

    “FAA cannot conclude that operations using just the lower portion of the spectrum are compatible with civil aircraft receivers without definition of LightSquared’s end-state deployment and further study,” the FAA said. “Proposed LightSquared deployment (both upper and lower channels by 2014) would result in an estimated aviation community cost impact of at least $72 billion and delay NextGen implementation by approximately 10 years.

    “Proposed LightSquared operations would severely impact the efficiency and modernization of the safest, most efficient aerospace system in the world.”

    Not Feasible. The National Aeronautics and Space Administration stated, in part:

    “NASA feels that due to the severity of the operational impacts, to both government and commercial users, it is conclusive that LightSquared’s implementation on the upper 10-MHz is not feasible in the near or long-term.”

    Constellation Updates from ION-GNSS

    During the Civil GPS Service Interface Committee (CGSIC) meeting held in conjunction with the ION GNSS 2011 conference in September, several presentations were given on the status and future of the global navigation satellite systems. Here are highlights, with updated information from elsewhere:

    GPS. As of today, 30 satellites are in operation and set healthy. SVN27/PRN27, a Block IIA satellite launched in 1992, was decommissioned on August 10, 2011. The satellite has been removed from broadcast almanacs but continues to transmit L-band signals, presumably for end-of-life testing.

    SVN35 returned to active service, once again, this time as PRN30, on August 16, to replace SVN30/PRN30, which was decommissioned from active service on July 20. SVN35 is being moved to the B1-F slot, previously occupied by SVN30.

    There are currently four backup or residual satellites: SVNs 30, 32, 37, and 49. SVN30 is deemed no longer usable and there are plans to dispose of it.

    SVN24/PRN24, a Block IIA satellite launched in 1991 and the second oldest active GPS satellite, reportedly experienced a reaction wheel failure on September 30. It has stopped broadcasting L-band signals.

    GLONASS. Currently, 23 GLONASS satellites transmit usable L-band signals; 22 are set healthy. The first GLONASS-K1 satellite is still undergoing flight tests and is set unhealthy. According to Sergey Revnivykh, deputy director general, Central Research Institute of Machine Building of the Russian Federal Space Agency, the satellite will likely not be set healthy for users in the near future, not even for just the legacy FDMA signals. It will be considered a backup satellite that could be pressed into service if necessary. This decision was taken based on the fact that five GLONASS-M satellites are scheduled to launch this fall — indeed, one did so on October 2 — and they should be adequate to maintain a healthy 24-satellite constellation for some time. The current GLONASS signal specification cannot handle more than 24 operational satellites.

    CDMA signals will be available to users from in-orbit GLONASS-K satellites by 2014.

     

    QZSS. The Japanese press reported that a government ministerial council consisting of the entire cabinet and headed by Prime Minister Yoshihiko Noda has taken the decision to expand the Quasi-Zenith Satellite System to seven satellites and will seek 4.1 billion yen (about $53 million) in the fiscal 2012 national budget to start the process. According to Hiroshi Nishiguchi of the Japan GPS Council, QZSS has a top priority in the budget.
    The future QZSS constellation structure is still under design. Nishiguchi stated that the constellation could involve a mixture of inclined geosynchronous orbit (IGSO) and geostationary Earth orbit (GEO) satellites. For a seven-satellite constellation, options include three IGSOs + four GEOs, or four IGSOs + three GEOs, or five IGSOs + two GEOs. He said that hopefully the funding and the future constellation structure will be known by the end of the year.

    Beidou-2/Compass. A special Compass workshop (see also the October issue of GPS World) stated that there are nine Compass satellites “in service.” But that may not be correct. While nine Beidou-2 or Compass satellites have been launched, Beidou G2, the first GEO to be launched, appears to be uncontrollable and is in a librating orbit. Some reports, perhaps overly optimistic, claim this satellite is undergoing “in-orbit maintenance.”

    The last IGSO satellite to be launched, Beidou IGSO4, may not be in service yet. One workshop presenter indicated that the currently used constellation consists of three GEOs and three IGSO satellites. It seems that the medium Earth orbit (MEO) satellite, Beidou M1, is not considered useful for actual applications at the present time. It was also stated that this satellite is undergoing “in-orbit maintenance.”’

    Two more Beidou-2/Compass satellites are to be launched in 2011 and five satellites are to be launched in 2012 to bring the number of operational satellites to 14 by the end of 2012: five GEOs, five IGSOs, and four MEOs. This is a sufficient number of satellites to provide the planned regional Phase II service. A 30-satellite global service, expected by 2020, will reportedly use three GEOs, three IGSOs, and 24 MEOs.

    Beidou-2/Compass will also offer a 1-meter level differential service.

    A Beidou-2/Compass Interface Control Document (ICD) is to be published this month. As of press time for this magazine, it had not yet appeared.

    — Richard B. Langley

  • Galileo IOV Satellites Succesfully Launched into Orbit

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    The first pair of satellites for Europe’s Galileo global navigation satellite system has been lofted into orbit by the first Russian Soyuz vehicle ever launched from Europe’s Spaceport in French Guiana in a milestone mission, reports the European Space Agency.

    The launch occurred one day after initially scheduled to resolve a problem with the ground-support fueling system.

    The Soyuz VS01 flight, operated by Arianespace, started with liftoff from the new launch complex in French Guiana at 10:30 GMT on October 21. All of the Soyuz stages performed as expected and the Fregat-MT upper stage released the Galileo satellites into their target orbit at 23,222 km altitude, 3 hours 49 minutes after liftoff. A launch replay is available. A look inside the IOV satellite is available on the BBC website.

    The two Galileo satellites riding the Soyuz are part of the In-Orbit Validation (IOV) phase that will see the Galileo system’s space, ground and user segments extensively tested. The satellites are now being controlled by a joint ESA and CNES French space agency team in Toulouse, France. After these initial operations, they will be handed over to SpaceOpal, a joint company of the DLR German Aerospace Center and Italy’s Telespazio, to undergo 90 days of testing before being commissioned for the IOV phase.

    The next two Galileo satellites, completing the IOV quartet, are scheduled for launch in summer 2012.

    “This launch represents a lot for Europe: we have placed in orbit the first two satellites of Galileo, a system that will position our continent as a world-class player in the strategic domain of satellite navigation, a domain with huge economic perspectives,” said Jean-Jacques Dordain, director General of ESA.  “Moreover, this historic first launch of a genuine European system like Galileo was performed by the legendary Russian launcher that was used for Sputnik and Yuri Gagarin, a launcher that will, from now on, lift off from Europe’s Spaceport.

    “These two historical events are also symbols of cooperation: cooperation between ESA and Russia, with a strong essential contribution of France; and cooperation between ESA and the European Union, in a joint initiative with the EU. This launch consolidates Europe’s pivotal role in space cooperation at the global level. All that has been possible thanks to the vision and commitment of ESA member states.”

    This was also the first Soyuz to be launched from a site outside of Baikonur in Kazakhstan or Plesetsk in Russia. A new site for Soyuz in French Guiana, operated by Arianespace, adds to the flexibility and competitiveness of Europe’s fleet of launchers.

    Soyuz is a medium-size vehicle, complementing ESA’s launchers: Ariane 5 handles large payloads, and the new Vega, planned to debut in 2012, will lift smaller satellites.

    Launching from close to the equator allows the European Soyuz to offer improved performance. From French Guiana, Soyuz can carry up to 3 tonnes into the ‘geostationary transfer orbit’ typically required by commercial telecommunications satellites, compared to the 1.7 tonnes that can be delivered from Baikonur.

    Source: GPS world staff
    The launch profile of the Galileo IOV satellites.