UPDATE: The next launch attempt for Soyuz VS09 with Europe’s fifth and sixth Galileo satellites is Friday, August 22, at 12:27 GMT, 14:27 CEST. Arianespace had decided to postpone the launch of Soyuz flight VS09 carrying Europe’s fifth and sixth Galileo satellites, because of unfavorable weather conditions over the Guiana Space Centre.
Follow the launch live. Streaming starts at 12:07 UTC/14:07 CEST.
The launch was originally scheduled for August21. Read more about the planned launch here.
UDPATE:
After a one-day postponement, The fifth and sixth Galileo satellites were successfully launched and deployed.
UPDATE:
Arianespace has decided to postpone the launch of Soyuz flight VS09 carrying Europe’s fifth and sixth Galileo satellites. This is due to unfavorable weather conditions over the Guiana Space Centre.
Another launch date will be decided depending on the evolution of the weather conditions in Kourou.
Europe’s latest Galileo satellites have been sealed within their launch fairing, atop the Fregat upper stage that will carry them into their final orbit on August 21, ushering in the system deployment phase and paving the way for the start of initial services. Galileo SATs 5-6 are scheduled to lift off at 12:31 GMT from Europe’s Spaceport in French Guiana on top of a Soyuz rocket.
The two Galileo satellites had been attached together on the dispenser that secures them during flight, and then delivers them into orbit. Then August 14 saw the follow-on installation of the stack — the two satellites plus dispenser — onto the Fregat stage. The following day was the last time the two Galileo satellites were seen by human eyes, as the two halves of the protective launch fairing were sealed around the satellites and their upper stage.
Meanwhile, on August 18, the satellites’ three-stage Soyuz launcher was moved by rail onto its launch pad then lifted to the vertical position. The launcher’s mobile gantry was then moved into position around the upright launcher. This allows the next step of the launch campaign to take place, the hoisting up and attachment of the entire upper composite — the launch fairing containing the Galileo satellites, their dispenser and the Fregat fourth stage. At three hours, 47 minutes and 57 seconds after liftoff, the satellites will then be deployed from their Fregat by the dispenser’s pyrotechnic separation system, once their final 23,500 km altitude is reached.
These new satellites will join four Galileo satellites already in orbit, launched in October 2011 and October 2012 respectively. This first quartet were in-orbit validation satellites, serving to demonstrate the Galileo system would function as planned. Now that work has been done, the Full Operational Capability (FOC) satellites being launched on Thursday are significant as the first of the rest of the Galileo constellation.
The August 21 launch can be watched live here.
This video by the European Space Agency recalls the success of Galileo’s in-orbit validation phase and explains what will be the mission of the fifth and sixth Galileo satellites, set to launch August 21.
Included is an interview with Sylvain Loddo, Galileo ground segment manager. The launch itself can be watched live here.
View the video below.
The special significance of next Thursday’s launch for the Galileo system as a whole is highlighted in a new video by the European Space Agency, with an interview with Didier Faivre, Galileo Program director.
On August 21, ESA will launch two more Galileo satellites on a Soyuz rocket from Europe’s Spaceport in Kourou, French Guiana. The satellites mark the beginning of a new phase for Galileo, the deployment phase, which will secure the completion of the constellation thanks to accelerated production of satellites and supported by regular launches.
At the same time, ESA and the European Union also look toward the future and are preparing the evolution of Galileo.
View the video below.
A new draft version of the Galileo Open Service Signal in Space Interface Control Document (OS SIS ICD), issue 1, revision 2, was published by the European Commission (EC) on June 30, and is available for download.
The European Commission has launched an open public consultation process in order to improve and consolidate the current draft document and to ensure that any further development of the Galileo OS SIS ICD takes into account the views of key GNSS stakeholders.
The OS SIS ICD contains the publicly available information on the Galileo Signal In Space. It is intended for use by the Galileo Open Service (OS) user community and specifies the interface between the Galileo Space Segment and the Galileo User Segment.
The public consultation process provides stakeholders with an opportunity to improve the quality and clarity of the document and to suggest new elements to be included in future versions, for instance, inclusion of multi-GNSS products and services. According to the European Commission, the public consultation process will contribute towards a smooth and rapid rollout of Galileo equipment and applications, and the earliest possible delivery of user benefits.
Comments are being accepted until September 22, 2014; a form for submitting comments is available via a link on this page.
UDPATE:
After a one-day postponement, The fifth and sixth Galileo satellites were successfully launched and deployed.
UPDATE:
Arianespace has decided to postpone the launch of Soyuz flight VS09 carrying Europe’s fifth and sixth Galileo satellites, because of unfavorable weather conditions over the Guiana Space Centre.
Another launch date will be decided depending on the evolution of the weather conditions in Kourou.
The next satellites in Europe’s Galileo satellite navigation system will be launched on August 21, ushering in the system deployment phase and paving the way for the start of initial services, according to the European Space Agency (ESA).
Galileo SATs 5-6 are scheduled to lift off at 12:31 GMT (14:31 CEST, 09:31 local time) August 21 from Europe’s Spaceport in French Guiana on top of a Soyuz rocket. They are expected to become operational, after initial in-orbit testing, in autumn.
The launch can be watched live here.
The two satellites will join the four Galileo in-orbit validation satellites already in space. Launched in pairs in October 2011 and October 2012, these four satellites — the minimum required to obtain a position fix — served to demonstrate and validate the space and ground segments of the system.
Galileo SATs 7-8 are scheduled to follow end of year 2014. Then the constellation will be gradually deployed with six to eight satellites launched per year using a series of Soyuz and Ariane launches from Kourou, along with remaining elements of the ground network.
Satellite “Midwives”
Galileo’s post-launch team at ESA has finalized its preparations for taking control of the twin satellites. Following launch, the most crucial point in the flight comes when the two satellites separate from their upper stage — and the Launch and Early Operations, or LEOP, phase begins, run from ESA’s Space Operations Centre, ESOC, in Darmstadt, Germany.
If the moment of separation is the point when satellites are born, then the LEOP team can be thought of as midwives.
Any tumbling from the satellites being pushed away pyrotechnically must be corrected, and their positions stabilized in space. Next, they have to deploy their solar wings, to ensure a steady flow of power.
Then comes time to switch on and check out all the satellite systems one by one, to ensure everything has endured the launch in working order.
If all goes well, LEOP should take about a week before control of the satellites can be handed over to the Galileo Control Centre in Oberpfaffenhofen, overseeing the satellites, and ESA’s Redu centre in Belgium, for detailed payload testing.
Galileo’s LEOP team has been in training for months, explained Hervé Côme, flight director for Galileo at ESOC, with preparations stretching back two and a half years. “A simulation campaign has been running since March and the system and its operators have performed flawlessly,” Côme said. “To date, 20 simulations, in both nominal and contingency cases, have been conducted.”
Testing Teams and Technology
The satellites themselves participated in multiple end-to-end system compatibility tests to ensure that they are fully compatible with the various elements of the Galileo ground segment, extending to far-flung ground stations variously belonging both to ESA and to France’s CNES space agency, the Agency’s partner for LEOP.
A joint team from ESA and CNES oversaw LEOP for the first four Galileo satellites, similarly launched in pairs in 2011 and 2012. That work was carried out from CNES’s LEOP and Network Operations Control Centre in Toulouse, France.
This time, ESOC is hosting the LEOP team, with mission control and flight dynamics systems inherited from the first four in-orbit validation satellites adapted for these new Full Operational Capability (FOC) Galileo models.
The LEOP procedures and timeline have been fully validated, and system configurations frozen. From here on in, ESOC’s Mission Control Team — following a short summer break — will concentrate on further fine-tuning their organization and procedures in advance of next month’s launch.
The troubled Galileo E20 satellite restarted E1 signal transmission Wednesday evening, August 6.
Galileo E20, also known as GSAT0104, the fourth in-orbit validation (IOV) satellite, has been set “unavailable until further notice” according to the European GNSS Service Centre because of a sudden, unexpected loss of power on May 27.
Based on a selected set of IGS MGEX stations and all CONGO stations, the first signals were tracked at AREG, AUT0, LLAG, and UNB3 at 23:13:00. No E5 signals and no navigation messages are currently transmitted. However, some JAVAD GNSS receivers report from time to time false E5a locks with zero or extremely small C/N0.
Based on information from the CANSPACE Listserv.
Chemring Technology Solutions has developed miniaturized GPS anti-jamming technology it has dubbed GINCAN. GINCAN is designed to combat illegal GPS jammers and is based on the adaptive antenna concept used by military systems. GINCAN has a chip footprint of six millimeters squared.
GINCAN’s reduced size and weight will significantly cut power usage and cost, the company said, making it ideal for combatting the widespread problem of low-powered GPS jamming. GINCAN can be integrated into a range of applications, including in-vehicle satellite navigation systems and cellular technology, and can be used for the protection of the critical infrastructures which rely on GPS to provide positioning and timing.
GPS jammers have already been developed to interfere with the European Union’s Galileo system, which will provide European satellite navigation independently from the Russian, USA and Chinese systems by 2019. Chemring Technology Solutions, based in Romsey, England, has anticipated this problem and its GPS anti-jamming technology will also support systems using Galileo.
Once the preserve of the military, there is now an increasing demand for GPS protection in the civilian market as illegal GPS jamming equipment becomes widely available on the Internet. The £1.5 million government-funded Sentinel project, designed to measure GPS jamming on UK roads, recorded more than 60 individual jamming incidents across six months at a single location. Such attacks could seriously impact industries, including maritime, aerospace, the emergency services and even stock market trading.
“Many years of developing GPS protection technology for the military has enabled our research and development team to miniaturize anti-jamming technology,” said Martin Ward, product manager, Chemring Technology Solutions. “GINCAN can now be easily integrated in to a range of applications to provide effective protection against jamming devices.
“As we become increasingly reliant on GPS technology, and low-cost jammers are proliferating, so a potential time bomb is being created. Chemring Technology Solutions is now able to offer the answer to this problem with jammer protection at a reduced size, weight, power and cost footprint.”
GINCAN is an export controlled product and subject to UK export restrictions.
By Gerhard Beutler, Rolf Dach, Urs Hugentobler, Oliver Montenbruck, Georg Weber, and Elmar Brockmann
What Happened: On April 1, 2014, at 21:15 UTC, all GLONASS satellites started to transmit wrong Broadcast Messages (BM) as previously reported by GPS World. The satellite positions derived from these BM were wrong by up to ± 200 kilometers in each of the three coordinates x, y, and z of the Earth-fixed, geocentric, equatorial coordinate system. The problem disappeared after an hour (after two erroneous BM) for two GLONASS satellites; for other satellites, the problem lasted much longer: up to 10 hours. By about 07:30 UTC on April 2, the April Fools’ “joke” was over.
Effect on GPS/GLONASS Receivers
Essentially, we can distinguish two classes of receivers: those using the GLONASS BM for tracking and those not using them. The first class of receivers “became aware” of problems in real time, because GPS and GLONASS observations did not result in a consistent position estimation. In the best case, all affected GLONASS observations were flagged (and removed from further consideration) and the positioning worked properly with a reduced number of satellites. In the worst case, the receivers stopped tracking GPS and GLONASS satellites completely. The second class of receivers tracked GPS and GLONASS normally. The tracking problems created a major uproar in the user community of combined GPS and GLONASS receivers.
On June 3, 2014, at the 13th meeting of the U.S. National Space-based Positioning, Navigation, and Timing (PNT) Advisory Board, Gerhard Beutler, representing the authors of this article, delivered a presentation including an example of a permanent network of GPS and GLONASS dual-system receivers in Switzerland and neighboring countries, where about 40 percent of the approximately 60 receivers stopped tracking both GLONASS and GPS satellites. The malfunctioning receivers had to be reset manually on the morning of April 2 (for more information, see: www.gps.gov/governance/advisory/meetings/2014-06/beutler1.pdf).
Event as Viewed by the IGS
At first sight, the GLONASS April 1 and 2 event was actually a non-event for the International GNSS Service (IGS). The IGS is a voluntary federation of more than 200 worldwide agencies that pool resources and data from about 400 permanent GPS and GLONASS stations to generate precise GPS and GLONASS products.
The IGS product series, including precise GPS and GLONASS ephemerides, were generated as usual before, during, and after the event. On April 4, a quick analysis by Urs Hugentobler revealed that only the GLONASS BM were affected; the GLONASS code (pseudorange) and phase observations and the GLONASS satellite clock corrections, were not affected.
Figure 1 shows that the GLONASS event started simultaneously for all satellites (for stationary receivers, the first wrong positions were calculated for 21:00 UTC, based on the BM with Time of Clock (ToC) at 21:15 UTC). The problem was fixed for the first two satellites (the GLONASS satellites in orbital slots 6 and 23) one hour later; the last satellite wasn’t fixed until 07:30 on April 2 (using the correct BM at 07:45).
More than 60 percent of the more than 200 combined GPS and GLONASS receivers in the IGS network tracked the GLONASS satellites normally. Fewer than 40 percent of the combined-constellation receivers had serious data outages (for GLONASS or even for both GLONASS and GPS). The number of GLONASS observations used in the daily work of the IGS analysis centers (ACs) was, however, only reduced by about 10 percent on April 2 (and even to a lesser extent on April 1). The small reduction is explained by the fact that only the last three and the first seven hours of April 1 and 2, respectively, were affected.
As the IGS ACs do not need the BM (neither for GPS nor for GLONASS), but may rather use their predicted orbits derived from the precise ephemerides of the preceding days, the number of good observations was still amply sufficient to calculate precise GLONASS orbits for April 1 and 2, essentially at the expected accuracy level.
Detailed Analysis
To further explore the structure of the problem, the BM-derived satellite positions were used as pseudo-observations in an orbit determination process. Orbit determination was successful when analyzing only “good” positions (prior to April 1, 21:00 or after April 2, 07:30). Orbit determination was successful, as well, when using only positions from “bad” BM. Successful means that the root-mean-square (RMS) error of the orbit determination process was of the order of about 0.5 meters per satellite coordinate — the expected order of magnitude.
As the bad satellite positions are now known to obey the laws of orbital motion, one may further investigate the nature of the differences between the “good” and the “bad” orbital positions. For that purpose, the precise GLONASS orbits of the IGS Center for Orbit Determination in Europe Analysis Center served as a reference. Its orbital positions were compared in the inertial coordinate system (one not rotating with the Earth) to the erroneous BM-derived positions by means of an orthogonal transformation, where only the three rotation angles around the x-, y-, and z-axes of the inertial equatorial coordinate system were estimated.
Table 1 shows that the positions derived from the normal (“good”) GLONASS BM compare very well to the IGS precise orbits. Except for a minor rotation about the z-axis, one obtains zero-rotations about the orthogonal axes in the inertial coordinate system.
Table 1 also shows that the “bad” positions were obtained from the reference positions by a rotation of about 0.5 degrees around the inertial x-axis. The RMS of 71 meters should be compared to the entire effect of up to 200 kilometers per coordinate. Comparing this RMS of 71 meters with the RMS of the orbit determination of about 0.5 meters per coordinate also says, however, that the “true” transformation is more complicated than one represented by just a series of three rotations.
We did not further investigate how this more or less consistent rotation could enter into the GLONASS BM. It seems to be clear, however, that a systematic error slipped into the realization of the GLONASS BM, which were activated at a common reference epoch for all satellites (but uploaded to individual satellites at different times).
Figure 1 suggests that the problem was almost immediately recognized by GLONASS operators: already an hour later the first two satellites started to transmit BM with the usual accuracy level.
Figure 1 also supports the idea that the problem was remedied satellite-by-satellite. A back-of-the envelope calculation revealed that the satellites were above the horizon of at least one of the Russian uplink sites at the times of switching back to the correct BM.
Summary and Conclusions
The GLONASS event was one that we might have described by the phrase “such a thing can never happen.” For the user community, the situation was aggravated by the fact that the event was not reported through the official Russian channel by issuing a Notice Advisory to GLONASS Users (NAGU). This definitely should have happened in the interest of transparency.
The above analysis was based on information available through the IGS. It was performed weeks after the event. It is worth noting, however, that the information needed for the analysis was available in real time. The reference orbit used in the analyses could have been replaced by the IGS predicted orbits generated in the ultra-rapid series.
In view of the importance of BM for all users and in particular for the users of IGS real-time products, the IGS might consider monitoring the quality of BM for all GNSS.
In a May 23 conversation with journalists, Javad Ashjaee, president of JAVAD GNSS, decried the recent controversy about monitoring stations on both U.S. and Russian soil, saying it was based in misinformation and misinterpretations, inflated by a political crisis. He also supplied a different perspective on the GLONASS signal outage than has been reported in other media outlets.
“There was speculation in early April that it took GLONASS 11 hours to correct a software bug because it took that long for all the satellites to pass over a control station on Russian soil. This was not the case, I have learned from conversations with their engineers and with the head person responsible for all of this. One engineer made a mistake and uploaded the wrong software. Until they could find it and debug it — and it took them 11 hours to do so — they could not upload correct software to the satellites.
“The 11-hour outage was not due to a wait for all satellites to pass over ground control stations on Russian soil to receive a fresh upload of data,” continued Ashjaee. “GLONASS has the capability, like GPS, to make updates via inter-satellite communication. The delay was caused by the time it took to find the bug in the erroneous software that had been uploaded and correct it.”
Ashjaee addressed the monitoring station controversy, saying that Russia had sought GLONASS monitoring stations in the United States, not for uploading any data, but for monitoring GLONASS satellites to provide more accurate orbit and clock information, for the free benefit of all users.
Click here for Ashjaee’s full discussion of the U.S.–Russian monitoring station controversy. For news updates on the situation, see http://stage.globalpositioningnews.com/tag/russian-monitoring-stations/.
A single GLONASS-M satellite was launched from the Plesetsk Cosmodrome on June 14. GLONASS-M 55 (with designation 755 once operational and also known as Kosmos 2500), was inserted into the constellation’s Plane 3 and will occupy orbital slot 21.
Manufacturer Reshetnev reported that the satellite is equipped with an experimental payload capable of transmitting signals in the L3 frequency band. The L3 signal, centered at 1202.025 MHz , is CDMA unlike the GLONASS legacy FDMA signals. The experiment will include flight testing of the new equipment and evaluation of its accuracy characteristics. The GLONASS-K1 test satellite also transmits an L3 signal.
Copernicus, “the younger brother of Galileo,” will be the main implementation of Galileo and other GNSS technologies going forward in Europe, according to to Paul Weissenberg, EC deputy director general for enterprise and industry. An Earth-observation satellite program administered by the European Space Agency to provide accurate and timely information to improve the management of the environment, understand and mitigate the effects of climate change, and ensure civil security, Copernicus was previously known as the Global Monitoring for Environment and Security (GMES).
Sliding to the Right. Galileo will make its “early-service declaration in the first half of next year,” said Matthias Patschke, director of EU satnav programs. This appears to back off slightly from previous dogged determination to declare services before the end of 2014.
The EC may propose legislation to make mandatory the use of GNSS technology in different areas: as with eCall, starting in 2015, including Galileo in the receivers inside cars, according to Marian-Jean Marinescu, member of the European Parliament.
Peter Large of Trimble spoke out against the mandating of a specific GNSS use in any market: “A bad policy outcome that moves backward into regionalization.”
For an expanded report, see the June GNSS Design & Test e-newsletter.