GPS World

Tag: GPS modernization

  • Lockheed, Raytheon Complete First Launch Exercise for Next-Gen GPS Satellites

    Raytheon Company and Lockheed Martin have successfully completed the first launch readiness exercise for the U.S. Air Force’s next generation GPS III satellites. The exercise is a key milestone demonstrating the team remains on schedule to achieve launch availability in 2014, the companies said.

    The Lockheed Martin-built GPS III satellites and the Raytheon-developed next generation GPS operational control system, known as OCX, are critical elements of the U.S. Air Force’s effort to affordably replace aging GPS satellites while improving capability to meet the evolving demands of military, commercial and civilian users worldwide. This is the first space and ground enterprise successfully building the ground control and space vehicles by two independent prime contractors.

    The launch readiness exercise, completed over a three day period by mission operations personnel, validated the basic satellite command and control functions, tested the software and hardware interfaces and demonstrated basic on-console procedures required for space vehicle contacts during the launch and early orbit mission.  The event sets the stage for the first GPS III satellite’s mission readiness timeline, which includes five short-duration exercises and six, five-day mission rehearsals leading up tolaunch.

    “Completion of our first GPS III launch readiness exercise is a major milestone for the entire GPS enterprise and is a solid indictor that our space and ground segments are well synchronized,” said Col Bernie Gruber, the director of the U.S. Air Force’s Global Positioning Systems Directorate.

    To achieve first launch availability in the 2014 timeframe, the U.S. Air Force awarded Lockheed Martin and Raytheon contracts in January of this year to provide a Launch and Checkout Capability (LCC) for launch and early on-orbit testing of all GPS III satellites.  At the heart of the LCC is Raytheon’s Launch and Checkout System that will provide satellite command and control capability, an integral part of OCX’s  support of the first GPS III launch.

    “The completion of our first launch readiness exercise is an important milestone for the entire GPS enterprise,” said Keoki Jackson, vice president of Lockheed Martin’s Navigation Systems mission area. “This achievement is a testament to efficient planning and synchronization by the U.S. Air Force and demonstrates that we are on track to deliver critical GPS III capabilities to military, commercial and civilian users worldwide.”

    “This milestone represents the hard work and dedication of the entire GPS III and OCX government-industry team,” stated Ray Kolibaba, a vice president of Raytheon’s Intelligence and Information Systems business and GPS OCX program manager. “This is another demonstration of the rapid progress we’re making on OCX development, while maintaining GPS space-ground enterprise alignment. I’m confident that we’ll be prepared to support the first GPS III launch with an efficient, evolvable and secure ground control system built independently.”

    The GPS III team is led by the Global Positioning Systems Directorate at the U.S. Air Force Space and Missile Systems Center. Air Force Space Command, based at Schriever Air Force Base, Colo., manages and operates the GPS constellation for both civil and military users.

  • Upcoming Navigation Satellite Launches Scheduled

    News courtesy of CANSPACE listserv.

     

    Launch dates this fall for GNSS satellites are as follows, according to various sources:

    Compass M2 and M5: September 18, 18:12 UTC (speculative); Compass G6: No earlier than October 1.

    GSAT-10 (includes a GAGAN SBAS transponder): September 21.

    GPS IIF-3: October 4, 2012. Launch window: 12:10-12:29 UTC.

    Galileo IOV FM3 and FM4: October 10, 18:31 UTC.

    Luch-5B: Originally scheduled for October 15, launch has slipped to no earlier than November 1 due to an issue with the “Briz-M” upper stage, which caused the loss of the Telkom-3 and Ekspress-MD2 communication satellites during their launch on August 6.

    GLONASS-K1 (block K2s): November 14.

  • The System: Next GPS IIF in October

    Next GPS IIF in October

    The next GPS satellite, Block IIF-3 (SVN65), scheduled to be launched on October 4, will be positioned in orbital slot 1, which is in plane A. This slot is currently occupied by a Block IIA satellite, SVN39, operating as PRN09. SVN39 is one of the oldest operating satellites in the GPS fleet, dating from June 1993. SVN65 will the the third of a projected 12 IIF satellites to attain orbit.

    Galileo IOV Tandem in October, Too

    The previously announced September 28 launch date for the second set of Galileo IOV satellites has reportedly been pushed back to October 10.

    Meanwhile, after more than four years of service as a Galileo testbed satellite, GIOVE-B was retired on July 23. Its navigation transmitters were switched off, according to an announcement from the European Space Agency, and the satellite’s height was raised in a series of steps to a graveyard orbit where there will be no danger of it interfering with the operational Galileo satellites or other spacecraft.

    The SES-5 geostationary communications satellite (also known as Sirius 5 and Astra 4B), launched in July, arrived at its orbital slot of 5 degrees east longitude late that month. The current position is actually about 5.2 degrees. The satellite carries L1 and L5 transponders for the European Geostationary Navigation Overlay Service (EGNOS) satellite-based augmentation system. The GPS Directorate has assigned C/A PRN code 136 and L5 PRN code 136 for use by the satellite.

    GAGAN in September

    India’s GSAT-10 telecommunications satellite — one of two passengers for Arianespace’s upcoming Ariane 5 mission on September 21 — has completed pre-flight preparations at the Spaceport in French Guiana. Aboard GSAT-10 is the GAGAN (GPS and GEO augmented navigation) payload, which will support the Indian government’s implementation of a satellite-based regional capability to assist aircraft navigation over Indian airspace and in adjoining areas. GSAT-10 is expected to be positioned at 83 degrees east longitude and use PRN code 128. It will join the first GAGAN-equipped satellite, GSAT-8, launched in May 2011, and now at 55 degrees east longitude and transmitting test signals on the L1 frequency using C/A PRN code 127. 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.

    GLONASS SBAS in September as Well

    Luch-5B, the second of three geostationary satellites to reactivate Roscosmos’s Luch Multifunctional Space Relay System, is scheduled for launch no earlier than November 1, 2012, to be positioned at 16 degrees west longitude. The system’s multi-functional satellites carry transponders for the System for Differential Correction and Monitoring (SDCM), Russia’s satellite-based augmentation system. The transponders will broadcast GNSS corrections on the standard GPS L1 frequency using C/A PRN codes assigned by DoD’s GPS Directorate.

    Luch-5A, launched in December 2011, has been placed in an orbital slot at 95 degrees east longitude. It began transmitting corrections on July 12, using PRN code 140.

    SVN49 Back on the Air, Unhealthy

    The GPS Block IIR-M satellite, SVN49, briefly resumed transmissions as PRN24 on August 9. The signals were marked unhealthy and the satellite was not included in broadcast almanacs. SVN49 was launched in March 2009, but remains out of service until an L1/L2 satellite multipath issue is resolved. Although not in the almanacs, a number of stations of the International GNSS Service tracked SVN49. See http://gge.unb.ca/test/IGS_stns_tracking_G24_223.pdf. SVN49 stopped transmitting signals as PRN24 on August 22. SVN49 previously operated between March 28, 2009, and May 6, 2011, as PRN01, and between February 2 and March 14, 2012, as PRN24.

    Beidou Begins Testing Network

    China will build a Beidou testing and certification network over the next three years to sharpen the system’s global competitiveness, according to a statement from China’s Certification and Accreditation Administration. By 2015, a national testing center will be set up in Beijing, while seven local sub-centers will be established across the nation, it said. The centers will test the safety and accuracy of products designed for use with Beidou and qualify them for civilian use. China plans to launch 30 satellites to complete the system by 2020.

    The launch of next two Beidou-2/Compass medium-Earth-orbit satellites, M2 and M5, did not occur in August as was previously speculated. A knowledgable source states: “All three active Chinese tracking ships have retreated to their home base Jiangyin, north of Shanghai. (Two ships are required for tracking down-range for a typical Chinese beyond-low-Earth-orbit launch.) The launch was put off for the remaining part of August and at least the first couple of weeks in September. The most recently speculated launch date is September 18.”

     

  • Next GPS IIF Satellite Launch Expected October 4

    News courtesy of CANSPACE Listserv.

     

    Spaceflight Now is reporting that the next GPS satellite, Block IIF-3 (SVN65) to be launched on October 4, 2012, will be positioned in orbital slot 1, which is in plane A. This slot is currently occupied by a Block IIA satellite, SVN39, operating as PRN09. SVN39 is one of the oldest operating satellites in the GPS fleet, having been launched on June 26, 1993.

    This will be the third satellite in the Block IIF series of GPS spacecraft with improved accuracy, enhanced internal atomic clocks, better anti-jam resistance, a civil signal for commercial aviation (and others) and a longer design life. Boeing is building a dozen craft to upgrade the constellation’s foundation over the coming years.

  • The System: GPS III Endures Bad Press, IIAs an OCX Concern

    GPS III Endures Bad Press, IIAs an OCX Concern

    Reports in daily news media such as the Washington Post and Denver Post that “Lockheed Martin will lose its entire fee of about $70 million to defray an 18 percent cost overrun” on GPS III satellites misconstrue the facts.

    Don Jewell, contributing editor for GPS World, said after informal talks with key Lockheed executives, “This is a good story, but it has been sensationalized.”

    Lockheed Martin’s fee is 5 percent of the target cost, which includes one-time engineering tasks, test equipment, and satellite assembly, according to the Air Force.

    The first GPS III satellite remains on schedule to be available for launch in 2014, Lockheed Martin spokesman Michael Friedman said via email.

    “While we have encountered challenges associated with higher standards for parts testing and first-time technical issues, the program is on firm footing and our cost estimate remains within the original Air Force budget,” Friedman stated, adding that the company doesn’t discuss specifics of fees.

    “In their defense,” Jewell reports, “the program was initially identified as stable with no government change request allowed, to keep it on schedule and budget. The recent budget furor has introduced chaos into the requirements process and contributed significantly to the increased costs.”

    Lockheed Martin is using a full-sized prototype to identify and solve many assembly issues “that would have cost more and presented more risk if they had been discovered later in production,” Lockheed’s Friedman said.

    “We have identified tens of millions of dollars in cost savings for the production satellites and in some cases we are seeing 50 to 80 percent reductions in labor costs,” he added.

    Ground Control to Aged Birds

    By Don Jewell

    One of the long-standing issues for support of IIA vehicles after the future GPS Operational Ground Control Segment’s (OCX’s) ready-to-operate (RTO) date, which should fall in December 2016 at the latest, is what ground command-and-control (C2)system will steer GPS IIA satellites, do navigation uploads, and so on. The issue is that AEP, the current C2 system, will no longer be available once the transition to OCX takes place, and OCX has no requirement to control IIA satellites.

    The OCX program, which struggled early, is now under new program leadership within Raytheon Space Systems, and while Ray Kolibaba, the new OCX program manager, is making great progress, OCX does not need to be burdened with additional requirements at this stage of the program.

    Just how big an issue is GPS IIA C2? Initially the Aerospace projections were that there would only be one or two GPS IIAs left on orbit in 2017, and it was not worth the costs to include the C2 software for the legacy system in the new software code. However, I have long maintained that Aerospace and Space Missile Systems Command (SMC) neglected to count the residual satellites, maintained by Launch, Anomaly, and Disposal Operations (LADO), which might very well actually amount to 3–4 additional IIAs. Added to the two IIAs on orbit, this could amount to six IIA SVs that need to be maintained.

    The solution announced during the week at the National Space Symposium (NSS, April 16–19) by General William Shelton, the four-star chief of Air Force Space Command, is to fund the current LADO operator, Braxton Technologies, to build in this support for the IIAs. This is significant for several reasons: One, of course, is that it solves the IIA C2 issues, it does it now, and at a relatively modest cost, and it utilizes more of the capabilities of the Braxton Technologies’ LADO software. Additionally it provides a true backup capability for assets on orbit that become increasingly valuable as the number of available launch slots for GPS decreases.

    Braxton Technologies initially demonstrated this capability years ago in a lifeboat drill during the transition to AEP, but the navigation upload capability was never maintained for LADO after the successful transition. This is certainly a step in the right direction and provides a simple solution to a vexing problem that has plagued the GPS program for the last several years.

    Dual Launch. I asked General Shelton if he would support an approach that would allow the United States to go to dual launch of GPS III on vehicles 5–6 instead of waiting until 8–9 as planned today. He said the Air Force would certainly support that, and is looking at making it possible with vehicle 7 currently. That will come even sooner if the program advances with glitches.

    I also asked him about the gap between GPS III launch and OCX RTO. The gap seems to be getting wider, not narrower, and he agreed that OCX could probably not move to the left, and GPS III has moved significantly to the left, so this is still an issue that needs to be addressed. There are plans in place, but the recent budget activity has caused some uncertainty.

    Sequestration. On the subject of sequestration — a highly charged Congressional effort to force another $500 billion-plus in additional defense cuts — General Shelton said it would come on top of the approximately $487 billion already cut from programs, and that many space programs might be unsustainable in their current mode if that occurs.

    However, the U.S. Armed Services have been informed by the White House Office of Management and Budget not to make plans for sequestration. So right now, the services and other agencies of the U.S. government have been forbidden to make programmatic decisions based on a possible sequestration. Interesting.

    By the way, attendance at NSS this year surpassed 9,000.

    Galileo Launches Accelerated, First Payload Shipped

    Javier Benedicto, head of the Galileo Project Office for the European Space Agency (ESA), set an aggressive schedule for launching some Galileo satellites as many as four at a time in 2014 and 2015, to meet a target provision date of Galileo initial services in 2014 and full services in 2015. The announcement came at the Munich Summit, March 14.

    The hurry-up to carry 22 satellites into orbit proceeds with dual-satellite launches aboard Russian Soyuz rockets, as was the case for the most recent in-orbit validation (IOV) launch in October 2011. There will be three Soyuz launches in 2013, for a total of six new satellites in orbit, and two Soyuz launches in 2014, adding four more. Then the burden will shift to European rockets from Arianespace, according to a contract signed in February of this year. One Ariane 5 rocket is slated to carry four Galileo satellites aloft in 2014, bringing the projected total of IOV and eventually operational Galileo satellites in space to 16 by the end of 2014. ESA had ealier aired plans for further Soyuz IOV launches in 2012, but the Munich statement did not mention these.

    In 2015, two more Ariane 5 launches will add eight satellites, for a total on orbit of 24, estimated to be sufficient for Galileo full operational capability (FOC).

    In subsequent talks with European satellite manufacturers OHB Systems and Astrium, GPS World contributing editor Don Jewell was told that the future launch schedule is “subject to change.”

    ESA headquarters has made no official announcement of a detailed launch schedule; inquiries regarding the Benedicto remarks were referred to the February contract statement, cited above.

    Payloads. Meanwhile, Surrey Satellite Technology Ltd. (SSTL) delivered the first of 14 FOC satellite payloads to prime contractor OHB System AG, for mechanical integration of the payload with the satellite platform and the beginning of overall vehicle assembly, integration, and testing for what will eventually become the fifth satellite in the Galileo constellation.

    Compass on the Grow

    Discussions in Internet forums indicate that the next BeiDou-2/Compass launch will take place on or about April 28, after this magazine goes to press. The launch purportedly will place two mid-Earth orbit satellites into space: BeiDou M3 and BeiDou M4. Sometime in June, plans call for BeiDou M2 and BeiDou M5 to be launched.

  • U.S. Air Force Awards Contract to Lockheed Martin for GPS III Launch, Checkout

    The U.S. Air Force has awarded Lockheed Martin a $21.5 million contract to provide a Launch and Checkout Capability (LCC) to command and control all GPS III satellites from launch through early on-orbit testing.

    The LCC, which will be integrated into the Raytheon-developed Next Generation Operational Control System (OCX), will ensure launch availability for the first GPS III satellite in 2014. The LCC includes trained satellite operators and engineering solutions in partnership with OCX to support launch, early orbit operations and checkout of all GPS III satellites before the spacecraft are turned over to Air Force Space Command for operations.

    “Achieving initial launch capability in 2014 is critical to introducing new GPS capabilities on time and will  enable the GPS III program to continue its production pace, maximize efficiencies and reduce long term costs for the GPS enterprise as a whole,” said Colonel Bernard Gruber, director of the U.S. Air Force’s Global Positioning Systems Directorate. “The Launch and Checkout Capability will ensure we can launch in 2014, effectively closing the time gap between GPS III and the Next Generation Operational Control System.”

    The GPS III program will replace aging GPS satellites while improving capability to meet the evolving needs of military, commercial and civilian users worldwide. The satellites will deliver better accuracy and improved anti-jamming power while enhancing the spacecraft’s design life and adding a new civil signal designed to be interoperable with international global navigation satellite systems, according to Lockheed Martin.

    The GPS III team is led by the Global Positioning Systems Directorate at the U.S. Air Force Space and Missile Systems Center. Lockheed Martin is the GPS III prime contractor with teammates ITT Exelis, General Dynamics, Infinity Systems Engineering, Honeywell, ATK and other subcontractors. Air Force Space Command’s 2nd Space Operations Squadron (2SOPS), based at Schriever Air Force Base, Colo., manages and operates the GPS constellation for both civil and military users.

  • The System: EGNOS Toolkits Enhance GPS Accuracy

    EGNOS Toolkits Enhance GPS Accuracy

    Free downloadable software Toolkits at www.egnos-portal.eu can help cell-phone and handheld receiver developers enhance location and timing applications with GPS corrrection data from the European Geostationary Navigation Overlay Service (EGNOS) satellite-based augmentation system.

    The Toolkits include software packages, demo applications, and supporting materials, enabling application developers, researchers, university students, and others to create, use, and maintain EGNOS-capable positioning applications.

    For handheld receiver manufacturers and mobile-phone developers, the Toolkit contains free source code for easy integration of EGNOS capabilities into a smartphone, and all the necessary files for the demonstration application, for use as a basis for a new application, as well as core libraries, to integrate enhanced EGNOS positioning capability into an existing application.

    For the simply curious, an EGNOS Toolkit provides a means of exploring and understanding the entire chain from the raw GNSS satellite signal to enhanced EGNOS positioning data.

    The development kit provides an easy way incorporate all EGNOS corrections and integrity capabilities, allowing developers to perform real EGNOS integration directly into a smartphone. It works with different operating systems, including Android, Apple, and RIM.

    Static and kinematic tests show that EGNOS performs well in both cases: “The EGNOS SDK provides an average increase of 30 percent in position accuracy over GPS alone,“ according to developer DKE Aerospace.


    EGNOS Software Development Kit provides a software receiver to enhance GPS positions, displaying position accuracy increases on average of 30 percent.

     

    DOT Blank Stare on LightSquared

    The U.S. Department of Transportation (DoT) responded to a Freedom of Information Act (FOIA) request by GPS World for its recommendations to the National Telecommunications and Information Administration (NTIA) regarding LightSquared interference with GPS. The DoT wrote, “We are withholding two pages [of thirteen relevant pages] in part and eleven pages in their entirety,” and enclosed two completely blacked-out pages.
    Kathy Ray, DoT FOIA officer, added,  “We have determined that the release of the redacted and withheld portions would foreseeably cause harm to the government’s deliberative process.”

    The blacked-out DOT letter is dated August 25, 2011. How it differs from the agency’s July 21 “LightSquared Impact Assessment,” publicly available courtesy of the U.S. House of Representatives Committee on Science, Space, and Technology, cannot, of course, be known.

    The Department of Homeland Security wrote in response to GPS World’s FOIA request, “We conducted a comprehensive search of files with the Science and Technology Directorate’s Homeland Security Enterprise and First Responders Group, and Cyber Security Division for records that would be responsive to your request. Unfortunately, we were unable to locate or identify any responsive records.”

    The National Institute of Standards and Technology of the Department of Commerce replied, “NIST has no documents that are responsive to your request.”

    The Department of the Interior provided the same documents that were previously made public by the House committee.

    The National Aeronautics and Space Administration made a similar determination, but did not send a document, referring instead directly to the committee’s public website.

    PNT Board Hears Proposal for LightSquared Solution

    The  November 9 meeting of the National Space-Based Position Navigation and Timing (PNT) Advisory Board in Alexandria, Virginia got several earfulls regarding the LightSquared/GPS controversy. One of seven speakers on a two-hour panel, Javad Ashjaee, president and CEO of JAVAD GNSS, demonstrated his company’s newly developed filter technology that he said could protect GPS receivers from LightSquared broadband network interference.

    As Ashjaee stated, the proposed solution does not protect against interference from the so-called high-10 signals, one of two bands (the other is known as the low-10) for which LightSquared has received a conditional waiver. Unless and until a solution for the terrestrial high-10 signals is found, LightSquared transmissions in that band will still interfere with the GPS signal. The technical solution proposed by JAVAD GNSS addressed only the low-10 band.

     


    Proposed filter to “harden” high-precision GPS receivers against Lightsquared Lower 10 (click to enlarge.)
    The JAVAD GNSS proposed fix consists, in simplified form, of a ceramic filter followed by a series of surface acoustic wave (SAW) filters.
    A PDF of Ashjaee’s 76-slide Powerpoint demonstration, without his verbal explanations and commentary, along with other presentations from the board meeting, are available at www.pnt.gov/advisory/2011/11/. A December 8 GPS World webinar reprised the same presentation, and the download at env-gpsworld-integration.kinsta.cloud/webinar includes audio of Ashjaee’s remarks.

    Ashjaee said that his company’s testing of its own filter methodology found no GPS signal loss due to a low-10 (10L) signal power of –10 dBm. An “Ultimate Test: Special Zero Baseline” put receivers on a Moscow skyscraper with multipath from both above and below. One antenna fed two receivers (zero baseline). One receiver used standard filtering and the other the new filters. He said that over 15 hours of testing the average carrier-phase error between the two receivers was 0.2 millimeters, and the average code difference was about 5 centimeters.

    JAVAD GNSS has started production of what Ashjaee calls “LightSquared-compatible” Triumph GNSS receivers. He brought 40 units to the PNT Board meeting. The company will begin manufacturing “LightSquared-integrated” receivers in May 2012, for RTK positioning using the proposed LightSquared broadband network for high-speed communication, if and when it is deployed.

    Fellow presenter Jim Kirkland, vice president and general counsel for Trimble Navigation, pointed out that such filters represented a potential solution only for one class of high-precision receivers. Whether it would work for other classes of high-precision receivers had yet to be verified. Kirkland said that even if further independent testing shows that the filter solution is viable at the lower 10 MHz of the spectrum, retrofits would be costly and time consuming.

    Questions regarding cost and responsibility of retrofit, should the solution prove practical, were not discussed at length at the meeting, nor was any solution proposed.

    LightSquared executive vice president Martin Harriman did not directly answer a question as to whether his company intends to develop the upper 10 MHz for which it has been given a conditional waiver.

    Scott Burgett, software engineering manager for Garmin International, said, “It is almost impossible to design new products compatible with LightSquared’s proposed system without knowing its technology’s end state.” He estimated 10–15 years to properly retrofit Garmin devices, which are widely distributed in general aviation, personal navigation, car navigation, and other sectors, so that they could coexist with LightSquared.

    The panel was moderated by Tom Stansell of Stansell Consulting, who concluded, “I think we learned, thanks to Javad, about a very clever solution to a particular problem for a particular range of products — the products he is most familiar with. It may or may not fit in some of the other applications.

    “What we have not addressed is the elephant in the living room,” Stansell continued. “That is the cost, and time delay, and changeover process if LightSquared is allowed to go forward. Will it be the lower 10, upper 10? That has to be resolved. There are very large questions remaining to be discussed, and [they] may or may not be fully solved in a short period of time.”

    Constellation Updates

    Where Is Compass ICD?

    The long-awaited signal interface control document (ICD) for China’s Beidou/Compass GNSS has not yet appeared, despite an announcement at the ION-GNSS conference by Chinese delegates that ICD document v1.0 will be published in 2011, “probably” in the month of October. When it does appear, it should be available for download on the Compass website, www.beidou.gov.cn (as yet without an English version), also at www.compass.gov.cn.

    The delay in publishing a document may reflect a system very much in formulation, with ongoing discussions among the principal parties to its design, with different views on system architecture and possibly even final signal structure. This was one possible conclusion that could be inferred — a dynamic system in formation and growing rapidly — from varying reports given by different Chinese representatives, governent and academic, at the ION Compass session.

    There was some disagreement among panelists at that time as to, for example, the final targeted number of satellites in the system: either 30, or 35.

    The ICD has been rumored to be available previously to receiver manufacturers within China, creating some disgruntlement among companies outside the country. One of the ION panelists affirmed that GPS/Compass chips and receivers are being actively developed by many Chinese manufacturers and research institutes.

    The next BeiDou/Compass launch, which will be for the system’s fifth inclined geosynchronous orbit satellite, is expected during the first few days of December, according to web discussions. As of press time for this magazine, there had been no official announcement on the Chinese official government BeiDou website, www.compass.gov.cn.

    The site has posted Chinese and English versions of a document titled “Report on the Development of BeiDou (COMPASS) Navigation Satellite System (V1.0)” by the China Satellite Navigation Office. The pages are viewable as separate images.

    Galileo Under Control

    Europe’s first two in-orbit validation satellites reached their final operating slotss 23,222 kilometers above Earth, have been activated, and are now undergoing tests of their navigation payloads, reports the European Space Agency (ESA).

    Marking the formal end of their Launch and Early Operations Phase, control of the satellites passed on November 3 from the French space agency (CNES) center in Toulouse to the Galileo Control Centre in Oberpfaffenhofen, 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. The navigation signals are being checked out by ESA’s ground station in Redu, Belgium, where a 20-meter antenna measures the shape of the signals to a high degree of accuracy. Once the navigation payload is fully checked out and activated, a second Galileo Control Centre in Fucino, Italy, will oversee all navigation services. All activities are performed under contract to SpaceOpal, a joint subsidiary of DLR and the Italian company Telespazio.

    GLONASS as Expected

    The Satellite System Mission Control Center of the Russian Ministry of Defence, with the ISS-Reshetnev Information Computation Center, established communication with the three GLONASS satellites launched November 4. The satellites are earth- and sun-oriented, and their subsystems are functioning properly.

    According to NORAD tracking, the three satellites were inserted into Plane 1. This was expected as there are only seven active satellites in this plane, whereas the other two planes have a full complement of eight satellites. Orbit slot 3 in Plane 1 is currently vacant. According to Nikolay Testoyedov, ISS-Reshetnev general designer and director general, the new satellites will ensure the operation of a complete 24-satellite GLONASS constellation, and allow creating the necessary orbital reserve.

    GPS GEO-MEO Floated

    In a presentation titled “Analysis of Alternatives  for Future GPS Architecture; Considerations for Constellation Sustainment,” made to the U.S. PNT Advisory Board on November 9, Kirk Lewis, senior advisor from the Institute for Defense Analyses (IDA), put forth the concept of “boosting” GPS III payloads onto commercial geostationary Earth-orbit (GEO) satellites.

    After concluding that the current program of launches and orbit costs extending into the Block III-C generation is not sustainable, Lewis presented several alternatives, but quickly eliminated two that involved low-Earth-orbit satellites and non-space options, due to technical, scheduling, and performance issues. Remaining in play are “potential and realistic” GEO and mid-Earth orbit (MEO, the configuration of the present GPS constellation) options, used individually or in combination.

    IDA analysis found that two GEO satellites, separated by 15 degrees or more longitude, supplied almost the same signal performance as adding six MEO satellites. The presentation is available at www.pnt.gov/advisory/2011/11/.

  • The System: GLONASS Forecast Bright and Plentiful

    At the Civil GPS Service Interface Committee meeting in Portland, Oregon, on September 20, Sergey Revnivykh, Deputy Director General of Roscosmos’s Central Research Institute of Machine Building, reported on the status and future of GLONASS.

    He provided a number of details on the present constellation and how it will be augmented in the future, stressing that GLONASS is doing well and that a full constellation of 24 primary satellites will be in operation within months. The average signal-in-space range error has improved by a factor of five in the past three years and presently stands at about 1.8 meters (one sigma).

    Figure 1. The GLONASS satellite generations through GLONASS-K2.
    Figure 1. The GLONASS satellite generations through GLONASS-K2.
     

    The present constellation consists of 20 healthy satellites with two reserve satellites, GLONASS 714 and 726. Revnivykh stated that GLONASS 726 had a failure of its navigation payload. It is known that the signal generator on the satellite is faulty and it had been set unhealthy since August 31, 2009. Nevertheless, it was placed in reserve status on March 19, 2010. GLONASS 714 is nominally healthy and could be brought back to service if needed. These initial reserve satellites are also being used to train the ground team to operate spare satellites in a full or nearly full constellation.

    GLONASS 727, in orbital slot 3, which was taken out of service on September 8, has also had a failure of its navigation payload and may not be returning to service. The three new satellites launched on September 2 are expected to enter service in early October. About 11 more GLONASS-M satellites will be launched by the end of 2012.

    Revnivykh announced that there will be two versions of the new GLONASS-K satellites: GLONASS-K1 and GLONASS-K2. GLONASS-K1 satellites will have a 10-year design life and a daily clock stability of 5 x 10-14.

    The first GLONASS-K1 satellite will be launched this December from the Plesetsk Cosmodrome about 800 kilometers north of Moscow. This will be the first launch of a GLONASS satellite from other than the Baikonur Cosmodrome. Only one more GLONASS-K1 satellite will be built and launched after that. The K1 satellites will test an open service CDMA signal on the GLONASS L3 frequency in the 1205 MHz band. Although the launch of the first GLONASS-K1 satellite will occur in December, the design process for the CDMA signal structure is not yet finished, according to a subsequent e-mail message from Dr. Revnivykh. When the process is completed, the structure will be made public.

    A completely new design, GLONASS-K2, will start launching in 2013. GLONASS-K2 satellites will have a 10-year design life and a daily clock stability of 1 3 10-14. Besides the CDMA signals on L3, CDMA signals will also be transmitted on L1 and L2. The GLONASS-K satellites will transmit the legacy FDMA satellites in addition to the CDMA signals.

    A modernized GLONASS-K satellite, GLONASS-KM, for launch after 2015, is now under study. In addition to transmitting legacy FDMA signals on L1 and L2 and CDMA signals on L1, L2, and L3, CDMA signals may also be transmitted on the GPS L5 frequency at 1176.45 MHz. Also being studied is an alternative to the present three-plane, equally spaced satellite constellation. A different constellation design would be possible using CDMA signals. Such a move would require that the legacy FDMA signals be switched off. Revnivykh stated that any such move would require at least 10 years’ advance notice.

    The signals that will be transmitted by the future generations of GLONASS satellites as well as those transmitted by the initial GLONASS satellites and the GLONASS-M satellites now on orbit are shown in Figure 2.

     
    Figure 2. Signals transmitted by the different generations of GLONASS satellites. OF 5 open-access FDMA, SF 5 special (military) FDMA, OC 5 open-access CDMA, OCM 5 open-access CDMA modernized.
    Figure 2. Signals transmitted by the different generations of GLONASS satellites. OF 5 open-access FDMA, SF 5 special (military) FDMA, OC 5 open-access CDMA, OCM 5 open-access CDMA modernized.

    Revnivykh also spoke on the satellite-based augmentation system under development, System for Differential Correction and Monitoring (SDCM). Correction and integrity data will be transmitted by Luch geostationary communication satellites now under development. Luch 5A, to be launched in 2011 and positioned at 16°W longitude, and Luch 5B, to be launched in 2012 and positioned at 95°E longitude, will transmit signals on an L1 frequency. Luch 4, to be launched in 2013 and positioned at 167°E longitude, will transmit on two frequencies. The three satellites will provide almost global coverage. The satellite payloads are under development.

    According to Revnivykh, the SDCM will make use of 12 monitor stations currently in operation in Russia and one in Antarctica at Russia’s Bellingshausen research station. However, the SDCM website indicates only 10 Russian stations currently in the test network. This anomaly might be explained by the fact that some locations have multiple monitor stations. Eight more monitor stations will be added in Russia and five more outside Russia. Revnivykh showed a map revealing the locations of the additional overseas stations as Cuba, Brazil, Vietnam, Australia, and an additional station in Antarctica. It is not intended, at least initially, that these stations would be used in generating the orbit and clock data broadcast by the GLONASS satellites themselves.

    Finally, Revnivykh stated that a GLONASS performance document will be released in the 2012–2013 time frame. His full presentation is available on the U.S. Coast Guard Navigation Center website (www.navcen.uscg.gov).
    Meanwhile, the three GLONASS-M satellites launched on September 2 have arrived at their designated orbital slots: GLONASS 736, plane 2, slot 9; 737, plane 2, slot 12; 738, plane 2, slot 16.

    The operating frequencies are not yet fully known. GLONASS 736, in physical slot 09, is currently undergoing experimental tests. It is included in the broadcast almanac at slot 16 and is transmitting on frequency channel -6. Stations in the International GNSS Service ground network are tracking the satellite. According to the Roscosmos Information-Analytical Centre, when the tests are completed, GLONASS 736 will transmit on channel -2 and be identified as slot 09 in the almanac. It is unclear if GLONASS 736 will replace GLONASS 722 also currently in slot 9, with the latter becoming a spare, or if GLONASS 736 will become the spare as previously inferred.

    GLONASS 737 and 738 have not started normal transmissions. Their assigned shared frequency channel is not yet known but -6 would be a likely candidate.

    Future GPS Control Segment Advances

    The Raytheon Company team developing the next-generation GPS Advanced Control Segment (OCX) successfully completed on schedule an integrated baseline review with the U.S. Air Force.

    When completed, GPS OCX will deliver a control segment designed to provide secure, accurate, and reliable navigation and timing information to military, commercial, and civil users. Raytheon is the prime contractor on the $886 million program. The team includes ITT, The Boeing Company, Infinity Systems Engineering, Braxton Technologies, and NASA’s Jet Propulsion Laboratory.

    Power Flex Positive

    From September 7 to 12, the U.S. Air Force Space Command (AFSPC) activated the long-awaited Flex Power demonstration for GPS, a power increase on L1 and L2. The trial of a new capability designed for military use under special circumstances was deemed a success, essentially going off without a hitch, according to Colonel David Buckman, AFSPC Command Lead for PNT, and Colonel Bernie Gruber, GPS Wing Commander.

    Officially, the flex power assessment ensured that the GPS control segment baseline (AEP 5.5) is properly integrated with the space segment with regard to command and control of High-Y Flex Power, a capability that increases the nominal transmit power of the desired signal by shifting power between signals (M-code and P(Y)) within a particular L-band. The net sum gain remains the same. High-Y Flex Power does not change total transmit power, does not affect phase stability between L1 and L2, is ICD-GPS-200E compliant, and does not affect the navigation message.

    Only a handful of 10-year-old reference receivers may have been adversely affected, possibly due to an outdated algorithm. Many government, commercial, and civil agencies were involved in the test, and hundreds of GPS receivers were closely monitored. As far as impacts to the overwhelming majority of global users, it was a non-event. The 2nd Space Operations Squadron (2SOPS) was able, over the course of five days, to make power changes to several GPS satellites without causing a phase shift and without the majority of users even knowing what was happening, although various announcements and press releases had appeared to alert them of the fact.

    All GPS satellites and signals have now returned to their normal power levels.

    Air Force Fends off GAO Zinger

    The U.S. Government Accountability Office has issued a follow-up to its alarming and much-criticized report, issued 16  months ago, on the health and prospects of the GPS constellation. Senior officers at the Air Force Space Command and Space and Missile Systems Center have characterized the new report as “overly pessimistic.”

    The report’s principal findings ­— that the Air Force continues to face challenges in launching its satellites as scheduled, which could affect the availability of the baseline GPS constellation, that on-orbit performance of IIF satellites remains uncertain, that a disconnect exists between GPS III and OCX, and that a predicted possible delay in GPS III could affect GPS constellation performance — are discussed and rebutted in detail by GPS World defense editor Don Jewell, with further commentary (paraphrased) by Air Force Space Command, in his October column.

    New Galileo ICD Embraced

    European Commission (EC) officials held a briefing during ION-GNSS in Portland for industry representatives, to discuss the new Galileo Open Service Signal-in-Space Interface Control Document (OS SIS ICD). Hosts Paul Verhoef and Michel Bosco said they were pleased with what they characterized as positive feedback from U.S., European, and Japanese industry representatives regarding collaboration and consultation over changes made in the ICD. The updated version is available.

    The EC grants free access to the technical information on the future Galileo open service signal: the specifications manufacturers and developers need to process data received from satellites. Anyone who wishes to use the intellectual property rights contained in the document simply needs to send an e-mail to [email protected] mentioning their request for a license agreement, which is without any exclusivity or geographic limitation.

    FAA Green-Lights ADS-B

    The U.S. Federal Aviation Administration (FAA) gave the go-ahead signal for full-scale, nationwide deployment of the satellite-based surveillance system called Automatic Dependent Surveillance – Broadcast (ADS-B) following its successful roll-out at four key sites. Air traffic controllers are now able to use the new technology to separate aircraft in areas with ADS-B coverage. Controller screens in those areas will show aircraft tracked by radar as well as aircraft equipped with ADS-B avionics, which broadcast their positions.

    The new system tracks aircraft with greater accuracy, integrity, and reliability than the current radar-based system, the FAA said. ADS-B targets on controller screens update more frequently than radar and display information including aircraft type, call sign, heading, altitude, and speed.

    Nationwide ADS-B coverage is scheduled to be complete in 2013. According to the FAA, every part of the country now covered by radar will have ADS-B coverage. More than 300 of the approximate 800 ADS-B ground stations that will comprise the entire network have been installed.

    By 2020, aircraft flying in controlled airspace in the U.S. must be equipped with ADS-B avionics that broadcast their position.

  • Air Force to Respond to GAO Report on GPS

    Global Positioning System experts from Air Force Space Command and the Space and Missile Systems Center will hold a media roundtable teleconference tomorrow, September 24, at 2:30 p.m. Mountain Time (4:30 p.m. Eastern Time) to discuss the recent GAO report titled “Global Positioning System: Challenges in Sustaining and Upgrading Capabilities Persist.” Colonel David Buckman, AFSPC command lead for positioning, navigation and timing, and Colonel Bernard Gruber, commander of the Global Positioning System Wing at Los Angeles Air Force Base, will participate in the teleconference.

    Air Force Space Command, which has responsibility for sustaining and maintaining the Global Positioning System, feels that the GAO report is overly pessimistic and doesn’t adequately acknowledge what AFSPC has done to address constellation sustainment, according to a press release issued from the Air Force, Peterson Air Force Base, Colorado. “The Air Force has created the largest, most accurate constellation, with the greatest capability, in the history of GPS, with 31 operational satellites currently on orbit,” stated the press release. “This is well above the 24 minimum satellites needed for a full constellation and to meet constellation performance standards. Since 1995, GPS has never failed to exceed performance standards.”

    The release continued, “AFSPC is working to mitigate the challenges identified by the GAO through a number of activities, including: applying a ‘back-to-basics’ approach to acquisition, continuing to identify additional ways to maximize the life of our operational satellites, implementing robust mission assurance processes, and transforming our launch enterprise.”

    The first GPS IIF satellite completed on-orbit testing and checkout and was set operational on August 26 as planned, the Air Force said, The GPS IIF program is ready for full rate production and continues to build confidence in its production line.  Through the institution of robust mission assurance processes, AFSPC is confident in the future of the GPS IIF program.

    The follow-on program, GPS IIIA, recently completed critical design review, two months ahead of schedule, the Air Force said. “AFSPC is optimistic that its ‘back-to-basics’ approach, including stable requirements, mature technologies, and more government oversight, will ensure a successful program, providing the GPS IIIA and its ground segment, OCX, within a timeframe that maintains a robust GPS constellation and supports GPS users.”

  • The System: Michibiki Takes Up Station and Other GNSS Constellation Updates

    The System: Michibiki Takes Up Station and Other GNSS Constellation Updates

    As this issue goes to press in late August, the first Japan Aerospace Exploration Agency Quasi-Zenith Satellite System (QZSS) space
    vehicle, nicknamed Michibiki, holds steady for a September 11 launch.

    QZSS will use multiple satellites in inclined orbits, placed so that one satellite always appears near zenith above Japan, well known for its high-rise cities. The design provides high-accuracy satellite positioning service covering almost all of the country, including urban canyons and mountainous terrain.

    QZSS Phase One will validate technological enhancement of GPS availability, performance, and application. Phase Two will demonstrate full system capability using three QZSS satellites, including Michibiki.

    The satellites will generate and transmit their own signals, compatible with modernized GPS signals. QZSS also transmits GPS corrections and availability data.

    Michibiki Profile. Dual-box shape with wing-type solar-array paddles; overall dimensions, 2.9 x 3.1 x 6.2 meters, paddles extending 25.3 meters; weight approximately 4,000 kilograms; altitude approximately 32,000–40,000 kilometers; inclination approximately 40 degrees;
    period, 23 hours 56 minutes.

    Compass. In early August, the first Beidou/Compass inclined geosynchronous orbit (IGSO) satellite achieved near-geosynchronous orbit. The mean east longitude of the sub-satellite ground point is currently 117 degrees, 19 minutes (see figure 1). This is one of the first, if not the first, satellite to use such a highly inclined circular geosynchronous orbit.

    QZSS-orbits
    Figure 1. Left, the orbit path of three QZSS satellites will eventually keep at least one of them directly over Japan at all times. Right, the inclined geosynchronous orbit of the fifth Compass satellite, launched in July, has a similar ground track and mission goal.

    Multi-GNSS Campaign. An international collaboration is poised to take advantage of a coming proliferation of satellites, led by Compass and QZSS but also including GPS, GLONASS, and Galileo, over the Asia/Pacific region. The website www.multignss.asia/campaign.html states, “The Asia and Oceania region is a unique place where the number of usable modernized navigation satellites will increase much faster than other areas in the world. We will see great improvement of PNT capability and hence there is a great opportunity to try, test, and validate new receiver hardware, algorithms, and applications in order to address user requirements.”

    The web page also carries an animation of the availability of more than 100 GNSS space vehicles that will operate over the region in the next decade. An initial campaign workshop in Bangkok, Thailand, in January drew 195 participants from 18 countries. A second workshop is scheduled for November 21–22 in Melbourne, Australia.

    GLONASS September. Three GLONASS-M satellites to be launched on September 2 completed pre-launch testing and mating to the upper stage of the booster rocket at Baikonur Cosmodrome. Numbered 36, 37, and 38, the satellites will constitute the Block 42 triad.

    GPS III Design: Done. The Lockheed Martin team developing GPS III has successfully completed the program’s Critical Design Review (CDR) phase, two months ahead of baseline schedule. CDR completion validates the detailed GPS III design to ensure it meets warfighter and civil requirements. It culminates many rigorous assembly, subsystem, element, space vehicle and system-level CDR events, validates the overall design maturity of the GPS III space vehicle, and allows Lockheed Martin to enter production phase. Col. Bernard J. Gruber, U.S. Air Force GPS Wing Commander, certified the completion. Lockheed Martin, ITT, and General Dynamics are working under a $3 billion development and production contract for up to 12 GPS IIIA satellites. The team is on track to launch the first GPS IIIA satellite in 2014.

    GPS Interface Specs. New IS-GPS-200E, IS-GPS-705A, and IS-GPS-800A documents have been posted to www.gps.gov/technical.
    SVN62 Rubidium Clock. The U.S. Naval Research Laboratory issued a preliminary report on the rubidium atomic clock currently in use on the SVN62 Block IIF satellite. While documenting excellent short-term performance, the report notes anomalous fluctuations in the clock signal with distinct 12-hour and 6-hour periodicities. The exact cause has not been identified although it is speculated that the fluctuations are of thermal origin like SVN-62’s L5 phase variance detected earlier. But note that the clock signal analysis relies only on L1 and L2 measurements.

    GPS IIF Got Active. The 50th Space Wing’s 2nd Space Operations Squadron formally took over command and control of the first Block IIF satellite on August 26 from the GPS Wing, and the satellite was set healthy on August 27, making 31 healthy GPS satellites on orbit.

    Advisory Board Update
    GPS World Editorial Advisory Board member Art Gower has been elected a Lockheed Martin Fellow, an honor recognizing pre-eminent technical individual contributors in the company, delivering mission success and vision by undertaking the most difficult technical challenges facing the company and its customers. Art started his career with IBM Federal Systems Division (now part of Lockheed Martin Integrated Systems and Global Solutions) in 1983, developing displays and performing navigation upload and command and control system engineering for the GPS control segment, and becoming chief engineer for the GPS control segment in 1990. He has spent the majority of his career working on GPS, GNSS, and SBAS systems.

  • The System: First IIF Satellite Speeds into Orbit

     

    At press time, GPS spacecraft IIF-1 was set to be launched May 27 from Cape Canaveral Air Force Station in Florida. This first of a new generation of satellites will travel quickly — instead of taking several days to reach its orbital slot, the new satellite should make the journey in three-and-a-half hours.

    The new IIFs will broadcast the operational civil L5 signal, intended for safety-of-life applications. It will be compatible with Galileo, GLONASS, and QZSS, with the goal to be interoperable as well. L5 will transmit at a higher power than current civil GPS signals, with wider bandwidth and lower frequency that may enhance indoor reception.

    IIF-1 caught its breathless ride aboard a Delta 4 rocket from the United Launch Alliance, a joint venture of Lockheed Martin and Boeing, formed in late 2006.

    Earlier GPS satellites rode on smaller Delta 2 rockets that, although reliable, did not possess the oomph to place space vehicles directly into the orbiting constellation, 11,000 miles high. Delta 2s put satellites into highly elliptical orbits looping from as low as 100 miles above Earth at perigee to the 11,000-mile apogee. At a strategic point, a solid-fuel kick motor attached to the satellites pushed them into position for circular orbit on high.

    The more powerful Delta 4 will shoot the IIFs directly into their destination slots. Future IIF launches may also use similarly equipped Atlas 5 rockets. The next IIF satellite, GPS IIF-2, could rise aboard an Atlas 5 as early as November.

    The IIF generation, manufactured by Boeing for the U.S. Air Force, is designed not only to broadcast the new civil L5 signal, but have a longer design life of 12 years and faster processors with more memory. “These next-generation satellites provide improved accuracy through advanced atomic clocks, a more jam-resistant military signal, and a new civil signal that benefits aviation safety and search-and-rescue efforts,” said Craig Cooning, vice president and general manager, Boeing Space and Intelligence Systems.

    “GPS IIF will increase the signal power, precision, and capacity of the system, and form the core of the GPS constellation for years to come,” said Air Force Col. David Madden, GPS Wing commander.

    A total of 12 IIF satellites will make their contribution to getting the new L2C and L5 signals closer to operational capability before the GPS III generation takes over, beginning with a 2014 launch.

    As the first spacecraft in the GPS IIF series, GPS IIF-1 underwent stringent and comprehensive testing following shipment to the launch site in February. Tests included verification of key satellite functions as well as end-to-end system testing to verify operations between the satellite and the ground control segment at Schriever Air Force Base in Colorado.

    Commands were sent from Schriever to GPS IIF-1 at Cape Canaveral to turn on payloads, reprogram processors, and verify interoperability with user receivers and equipment, both civil and military.

    Launch of the satellite, originally scheduled for May 20, was delayed four times because of various technical problems.

     

  • The System: Vistas from the Summit

    “This is an event where one gets one’s goals for the next year.” Paul Verhoef, program director for satellite navigation programs of the European Commission, may have exaggerated for effect, and for the benefit of his audience and hosts at the Munich Satellite Navigation Summit in March. But not by much.

    The conference, now in its eighth year, has assumed increasing importance on the international circuit of GNSS policymakers and communicators. Although with a decidedly European bent, it draws representatives from most if not all systems to mingle and present. A 16-member delegation from China’s Compass system furnished one of the liveliest topics of conversation — and speculation.

    “When we started in 2003, there were many technical conferences on the one side, and we saw a niche for the institutional and political side of satellite navigation,” said Berned Eissfeller of the Institute of Geodesy and Navigation, German Federal Armed Forces University, conference director and host. You can watch video clips of Eissfeller and other speakers.

    GNSS came in for a check-up, a sort of self-examination this time. The 2009 conference was titled “The GNSS Race,” but this year it was “GNSS — Quo Vadis?” The Latin phrase means “Where are you going?” Following program updates, sessions focused on safety-of-life, compatibility, legal/intellectual property, and privacy issues.

    Galileo. Paul Verhoef continued his remarks that open this story. “I have been given [my goal]: Galileo must succeed.

    “You know the world today is not what it was a year ago. It means obviously the financial crisis has had an impact on our economies, on public finance, and therefore I would not be surprised it may leave its mark on satellite navigation. The reason is simple: the systems that are either operating or being deployed are being publicly financed. Galileo is the only system that is financed from a purely civilian budget. All the systems need more than ever to demonstrate their public utility.

    “I put it to you that this is an opportunity. As we’ve already heard, there is much to be gained in this market. After the PC, mobile communications, and Internet, satellite navigation is the next breakthrough technology. There are enormous revenues foreseen and already present in this market. There are many jobs possible for those who want to get it, and we think from the European side we have an enormous chance of capitalizing on this among other things by investing in this technology. Therefore, Galileo- and EGNOS-based innovation is certainly politically of interest.

    “Obviously, it is not a path of roses. There will no doubt be many more critical questions during these days. However, from our side, we have set our goals. I think they are modest, but they are firm. We want to be the second system of choice. At least in the first instance, we will see where we will go after that. Obviously, this is going to cost a bit of time. I shall invite you, if you get impatient, if the public gets impatient, to look at the history of the other systems. Developing and deploying these other systems is costing time.

    “We think that Galileo will meet its deadlines. I think one of the important messages this year, and you have seen it, we are putting things in place. There are contracts in place, there are satellites on order, there are launches on order, there are installations being built — Oberpfaffenhoffen, Fucino, there are others around the world — EGNOS is operational, we’re going to declare the safety-of-life of EGNOS later this year. So we are really moving forward at good speed at the moment.

    “We need to win the hearts of the users, the application providers, and the service providers. At the downstream market is the real challenge for these systems. We need to help do that. We are addressing this among other things by providing a more and more reliable schedule for availability of Galileo and EGNOS services.”

    Galileo ICD Soon. “We are about to publish in the next couple of weeks the so-called signal-in-space Open Service interface control document, which I know a number of you have waited for a long time.

    “We need also to move forward at a political level. In this case, no GNSS system can be credible if it is not backed by a long-term political commitment particularly by its owner. So after the decision of the Parliament and the Council to deploy the system, these two institutions are now clearly called upon to provide us such political long-term commitment that is credible in the eyes of the users.”

    GPS. Anthony Russo, director of the U.S. National Space-Based PNT Coordination Office, said “Keeping cards close to the chest in a competitive situation can well become a liability, creating a future need for a re-work or undoing if you paint yourself into a technological corner.” This appeared to refer to China and its Compass system; information has been singularly difficult to obtain on almost every aspect of this budding constellation.

    Regarding the April 2009 U.S. General Accountability Office report that forecast gaps in constellation availability, Russo stated, “The GAO will revise its report somewhat. They were using a model that was a little too cautious, one used by the [GPS] Wing. But satellites on orbit have been performing past estimated life. Further, we can turn off secondary payloads to conserve energy onboard satellites [and thus extend life] if needed.”

    The next morning, Lt. Col. Liz Roper, Air Force Space Command, gave a status and modernization briefing; the most eagerly awaited development is the launch of the first Block II-F satellite, scheduled for some time in May. She alluded to “a few setbacks” from the August 2009 launch of SVN49 with its well-documented signal problems, but emphasized the episode’s “positive aspects: the relationships we’ve been able to build in seeking solutions to that situation.”

    GLONASS. Grigoriy Stupak, deputy general director and general designer on GLONASS systems, briefed the audience in fluent Russian. For a recent launch update, see story below.

     

    Compass. Two of the Chinese delegates spoke in the opening session. Jiao Wenhai from China Satellite Navigation Office did elaborate the basic principles of the Beidou (Compass) system:

    • openness (“China will widely and thoroughly communicate with other countries on satellite navigation issues.”)
    • independence
    • compatibility (“China will pursue solutions to realize compatibility and interoperability with other satellite navigation systems.”)
    • gradualness.

    He promised an English-language version of the governmental website www.beidou.gov.cn or www.compass.gov.cn “soon.” Wenhai recapped:

    • the frequencies Compass will use: 1561.098, 1207.14, and 1268.52 Mhz in Phase II until 2012; and 1575.42, 1191.795, and 1268.52 in Phase III by 2020.
    • the general development plan: five geosynchronous, five inclined geosynchronous, and four mid-Earth orbit satellites providing a Chinese regional service using mainly Compass Phase II signals; then development of a global service broadcasting mainly Compass Phase III signals from five GEO, three IGSO, and 27 MEO satellites.

    The Chinese speakers displayed a certain disingenuousness in giving verbally and in their slides the location of the January launch, Beidou G1 geostationary satellite, as 160 degrees East, somewhere over the open Pacific. When GPS World pointed out that NORAD satellite tracking shows G1 has been repositioned to a slot at 144.5 degrees East longitude, they huddled for several minutes before stating that yes, it had moved to that position and was undergoing in-orbit testing. That spot was previously occupied by Beidou 1D, apparently decommisioned about a year ago due to power problems. 1D currently orbits in graveyard above geostationary altitude.

    A personage civilly associated with the U.S. Air Force confirmed the actual G1 location to the magazine, and could only speculate that it was more advantageous to Chinese ground control for monitoring and testing. As to why spokespersons misstated the location, that remains inscrutable.

    GLONASS Back in Black

    Three GLONASS-M satellites launched on March 1 are expected to enter service on March 22 and March 30, according to deputy general director Grigoriy Stupak’s statement in Munich. This would bring the constellation, according to his calculations, to 23 operational satellites, though two of those are held in reserve.

    With 21 satellites broadcasting signals, the system claim 98.5 percent global availability. Block 42 (three more satellites) has an August 2010 launch date, and Block 43 one for November 2010. By December, Stupak predicted 24 active satellites on orbit, for 99.5 percent global availability.

    The GLONASS-M satellites have a stated seven-year lifetime. CDMA signals will begin with next-generation GLONASS-K satellites, while FDMA signals continue in parallel. The Russians plan to “reach 5-meter accuracy by 2017, almost equal to accuracy of other GNSS,” and are “paying more attention to differential corrections for integrity monitoring.”

    ICG Questions

    The International Committee on GNSS (ICG) Working Group on Compatibility and Interoperability invites GPS industry members to fill out a questionnaire, provided online in two formats: as a downloadable MS Word document or a PDF.

    The Industry and User Community Questionnaire is designed to obtain worldwide input from industry, academic institutions, and other representatives of the GNSS user community with technical expertise regarding GNSS signals and other system characteristics that aid or hinder the combined use of the signals in applications, equipment, or services. For instance, respondents are asked to grade certain signal characteristics as to their importance in overall interoperability considerations for a particular type of application.

    Respondents are asked to e-mail completed questionnaires to the ICG by May 28.

    To download instructions and the form, go to env-gpsworld-integration.kinsta.cloud/icg.