A new draft policy in India seeks to foster global use of its Indian NavIC satellite navigation system. The draft Indian Satellite Navigation Policy 2021 (SATNAV Policy 2021) is part of reforms of the Indian Space Research Organisation (ISRO)/Department of Space (DoS).
“ISRO/DOS shall work towards expanding the coverage from regional to global to ensure availability of [the] NavIC standalone signal in any part of the world without relying on other GNSS and aid in wide utilization of [the] Indian navigation system across the globe,” states the policy document.
DoS will push NavIC for global use to meet demand for positioning, navigation and timing in commercial, strategic and societal applications. It aims to ensure the continuous availability of free-to-air navigation signals for civilian uses, while providing secured navigation signals for strategic uses.
The draft document plans for continuity of NavIC and GAGAN services, while also ensuring Indian satellite navigation and augmentation signals are compatible and interoperable with other GNSS/SBAS signals. The International Telecommunication Union (ITU) regulated frequency allocation to prevent interference among signals from different systems. This interoperability allows users to seamlessly switch from one constellation system to another and results in improved navigation signal, especially in a situation where an area is obscured from one satellite system.
DoS will continue to work with ITU for frequency allocation. It will also take part in the United Nations Committee on Peaceful Uses of Outer Space (UNCOPUOS), International Civil Aviation Organisation (ICAO) and International Maritime Organisation (IMO).
In addition, ISRO will provide technical support for academic institutions in GNSS research and applications.
Telit has introduced a new positioning module aimed at India. The SL869T3-I combines GPS with India’s NavIC (IRNSS) navigation system and the country’s satellite-based augmentation system (SBAS), known as GAGAN.
The SL869T3-I module enables the creation of high-performance position reporting and navigation solutions. It complies with Automotive Industry Standard 140 (AIS-140) — an Indian government mandate that requires the use of NavIC for vehicle location tracking devices in all public transportation vehicles, effective April 2019.
The SL869T3-I is a 16 x 12.2-millimeter module with an LLC package. It is provided with a single RF input for L1 and L5 bands. It also contains Flash memory, a low noise amplifier (LNA) and SAW filters. The RF front end is specifically designed to comply with sensitivity specifications contained in AIS-140 standard.
“The new SL869T3-I is among the first IoT GNSS positioning receiver modules to deliver IRNSS/NavIC L5 coverage compliant with the Indian government’s AIS-140 regulation,” said Manish Watwani, EVP global product management, Telit. “This new addition to the Telit family of products results from more than 20 years’ experience in GNSS applications.”
For more information, visit booth C3.227 at Electronica, Nov. 13-16 in Munich, Germany.
SkyTraq Technology Inc., a fabless GNSS positioning technology company, has introduced the S1216F8-GI2, a NavIC + GPS/GAGAN receiver module for the emerging Indian market.
It integrates L1/L5 RF front-end and baseband processor capable of receiving up to 14 L5 NavIC signals and up to 20 L1 GPS/GAGAN signals simultaneously. With currently usable six NavIC signals and three GAGAN signals, it offers a total of 18-23 usable signals for navigation compared to 9-14 usable signals with conventional GPS receivers, providing improved accuracy in urban canyon environments with signals often blocked by high buildings.
The S1216F8-GI2 has form-factor and pin-out compatability with popular 12 x 16-millimeter GPS receiver modules, so customers using those GPS modules can effortlessly migrate to NavIC/GPS capability by drop-in replacement and changing to an L1/L5 antenna.
For emerging intelligent transport systems (ITS) applications requiring NavIC/GPS capability in India, S1216F8-GI2 enables fast time-to-market for product manufacturers, the company said.
NavIC sub-frame data output is a useful feature of the S1216F8-GI2. It can output NavIC broadcast warning messages related to weather alerts, forecast, and natural disasters such as cyclones, earthquakes and tsunamis.
An S1216F8-GI2 engineering sample, evaluation kit and datasheet is available. Volume delivery to customers begins in late March. The S1216F8-GI2 is manufactured with ISO/TS 16949 automotive certification.
The government of India has warned domestic airlines of “consequences” if they do not use GAGAN, the state’s GPS-Aided Geo Augmented Navigation system, reports the Mumbai Mirror.
The warning came during a meeting called by the Directorate General of Civil Aviation (DGCA) in December with all stakeholders, including the airlines. Most aircraft registered in India are still not equipped with the technology two years after its launch.
While smaller aircraft such as ATRs and Bombardiers in the Indian carriers’ fleet are already equipped with the GAGAN system, bigger planes need to be retrofitted at the airlines’ expense, including Airbus A320, A330, Boeing 737, B777 and B 787. Eight major domestic carriers — Air India, Air India Express, Jet Airways, JetLite, IndiGo, SpiceJet, GoAir, Vistara and AirAsia — have 427 such planes in service, Mumbai Mirror reports.
The National Civil Aviation Policy, announced by the government in June, makes it mandatory for all aircraft registered in India to be GAGAN-enabled by Jan. 1, 2019.
Jointly developed by Indian Space Research Organisation (ISRO) and Airports Authority of India (AAI), the GAGAN system was officially launched by Civil Aviation Minister Ashok Gajapathi Raju in July 2016. It is said to make airline operations more efficient and cut down costs as it reduces separation between aircraft, increases air safety and fuel efficiency.
GAGAN’s footprint extends from Africa to Australia and has expansion capability for seamless navigation services across the region. The system is inter-operable with other international satellite based tracking systems such as the WAAS (US), EGNOS (Europe) and MSAD (Japan).
All seven satellites of Indian Regional Navigation Satellite System (IRNSS) are expected to be in orbit by March 2016, reports New Delhi Television, citing Indian Space Research Organisation (ISRO) Chairman Kiran Kumar.
“We expect by March 2016 all the seven constellation of IRNSS to be in orbit,” Kumar said.
Four IRNSS satellites are now in orbit, with three remaining to complete the system. The next IRNSS satellite, 1E, is scheduled for launch in November, and 1F is set for launch in December.
Also, the GSAT-15 satellite, which has a GAGAN payload, will be launched on Nov. 10.
Kumar made his comments after inaugurating GNSS User Meet 2015 at the ISRO Satellite Centre (ISAC) in Bengaluru, India. The event was jointly organized by ISRO and Airports Authority of India (AAI).
Galileo Growth, Constellation Updates, and Jamming
I used to spend quite a lot of time in Munich working on a multi-national, multi-role fighter aircraft program, so returning for this year’s Munich Satellite Navigation Summit stirred some good memories for me.
Held in the opulent Residenz Muenchen March 25-27, the conference always has a special atmosphere that these historic 1385 surroundings convey to the attendees. The former royal palace of Bavarian monarchs, the whole complex has ten courtyards and 130 rooms. The summit was held in the Max-Joseph Hall, which took a little bit of work to find at first, wandering around the huge complex. One wing of the building hosts a theater, and the mainhall is the primary concert venue for the Bavarian Radio Symphony Orchestra. Overall, this is a delightful setting.
Munich is in the Southern German state of Bavaria, and Bavaria has taken a real interest in the promotion and success of Galileo; witness the extensive Bavarian booth at recent European and North American GNSS conferences. Germany has, of course, been one of the principle nations providing significant funding for Galileo from its inception.
Ilse Aigner
So with this backdrop, the summit brings together people involved with GNSS from around the world to report on the current status of GNSS and to relate how their participation in satellite navigation has progressed. And, of course, Europe, Germany, Bavaria and the European GNSS industry, which is now recognized around the world, all take the opportunity to present their capabilities and successes.
The plenary session on the first evening covered GNSS, Earth Observation (EO) and Telecommunications — with the panel headed by Ilse Aigner, Bavarian State Minister of Economic Affairs and Media, Energy and Technology — an extensive mandate, even for a state-certified engineer who used to work for Eurocopter.
Dr. Merith Niehuss, speaking at the opening of the summit. (copyright: Munich Satellite Navigation Summit).
The host of the summit is actually the University of the German Army in Munich, and we received a warm welcome from two leading professors: Dr. Bernd Eissfeller and Dr. Merith Niehuss, the president. The theme of the summit was to move from implementation to utilization, and in typical European form, all parties were looking to shower potential users with funded solutions to problems of which users are not yet aware — so users clearly need government-provided education, pilot projects and funding. Not exactly a North American concept, where we tend to encourage users to buy our innovative stuff by demonstrating how it can save them money or earn them more revenue.
The European Commission, ESA, DLR, European GNSS Agency (GSA), Airbus, OHB, and Telespazio were also represented. The minister did indeed associate with and praise the local area, claimed 1,000 jobs created related to Galileo through an incubation center at Oberpfaffenhofen, and declared Bavarian support for satellite navigation.
Other important things mentioned by the panel at the plenary included an €11B budget for Galileo/EGNOS and Copernicus (EO project) under the Horizon 2020 program, and an intent to declare Early Service for Galileo before the end of this year with two or three dual Galileo satellite launches — the first two FOC (production) SVs should go to the European launch center in Kourou in April in preparation for launch around June. I heard in a corridor that launches may be planned for June, October and December, but an EU spokesman later said that there would only be two launches this year. OHB now has the contract to build 22 FOC Galileo SVs, each with a design life of 14 years, and they are bullish on their ability to deliver on time and budget.
The program continued the following day with constellation updates from GPS, Galileo, Beidou and the UN International Committee on GNSS (ICG) — GLONASS delegates were notably absent. There was much speculation that they declined to attend due to the Crimean situation, and one U.S. delegate even inferred that they were “uninvited.”
Constellation Updates
GPS: It’s estimated that there are ~2B GPS receivers in use, and there may be ~10B by 2020. A return on investment (ROI) analysis is currently underway, but a rough guess is that costs are in the tens of billions, while annual returns are of the order of $60-100B/year. Another IIF satellite (SV) launched last month, bringing the total to five SVs transmitting L1, L2C and L5, with seven more to come, and multiple launches are expected this year. There are 30 operational SVs on orbit, signal performance significantly exceeds the specs, and consistent, dependable performance has been provided for more than 20 years.
Galileo: First fix was achieved March 12, 2013, with four SVs, two (maybe three?) launches of two SVs each planned for 2014, and early operational capability to be declared by end of this year. €7B in funding is provisioned for 2014-2020, with 16-24 operational ground stations, Commercial Service (CS) planned by 2016 (more on this later), and a long-term evolution plan being worked up during this year.
BeiDou: Fourteen SVs are on orbit — five GEO, four MEO and five Inclined Geosynchronous Orbit (IGOS) satellites, providing dual-frequency services. Thirty total SVs are planned, and the intent is to provide open, compatible, interoperable signals with other GNSS free of charge. There was not much other news to report, other than that China intends to invest significantly in BeiDou to keep improving services.
United Nations ICG: Nine nations and European Union = International Committee on GNSS (ICG), with 20 other associate and observer States. Activities include GNSS compatibility/interoperability, GNSS enhancements, information sharing, and reference frames, timing and applications — lots of upcoming meetings and activities.
Regional and Augmentation Updates
WAAS: Phase IV is underway with GEO replenishment begun, introduction of L5 to replace L2, and replacement of obsolete component parts. One hundred GIII receivers were ordered with L1/L2C and L5 capability for delivery by September this year — and have capacity to also add Galileo. GIII receivers have already been fielded in six locations as part of initial integration testing. The Safety computer will also be upgraded starting this year. 3,912 LP/LPV approaches have been approved, of which 3,379 LPVs serve 1,667 airports. GBAS CAT I is progressing with four U.S. airport installations. System design approval began in January this year, and United Airlines has begun equipping over 90 B737/B787 for GPS approach and landing. Alternative Positioning, Navigation and Timing (APNT) investigations are underway (as a backup to GPS) with a hybrid DME-pseudolite configuration currently favored. Stanford University subsequently presented this and other concepts.
EGNOS: A €1.58B budget has been approved, and EGNOS V3 evolution is underway, with L1/L5 and GEO (SES 5 and Astra 5B) replenishment, a requirement to expand East and West and to the North to provide full coverage to all EU States.
About 100 EGNOS LPV approaches are approved — this year, it’s hoped to add 150 more.
QZSS: The operational concept has been proven with the first IGOS SV (Michibiki), so Japan is moving forward quickly to add another three SVs (3xIGOS and 1xGEO) and ultimately would like to have a total of seven SVs in orbit providing QZSS services. L1/L1C/L2C/L5 signals are identical to GPS, and L1s/L5s are augmentation signals, while L6 is proposed to be similar to Galileo E6, providing centimeter-level PPP-type service. QZSS essentially is intended to provide higher elevation satellites to improve urban navigation in dense cities.
IRNSS: Coverage extends 1500 km beyond India. The target is <20-meter accuracy, and signals are in L5 and S band and can be used independently or in dual-frequency combinations. A second IRNSS-1B GEO satellite is scheduled to launch on April 4.
GAGAN: The Indian SBAS was commissioned and certified in February this year with a number of ground stations, redundant uplinks and two on-orbit GSAT 8 and 10 GEOs. Gagan is now qualified to provide RNP0.1 (navigation accuracy to 0.1 miles).
QZSS and Japan’s Space Policy
This session provided some detail on how changes in Japan’s Basic Space Law has lead to efforts to expand the use of space and derive further economic benefits that this provides.
Munich Highlights
A collection of examples of Bavarian GNSS innovations followed in a very interesting session led off by an overview of Business Incubation Centers and their collaboration with government agencies and research centers. Small business start-ups are apparently encouraged to apply during four annual time-slots, and receive two years’ incubation support and cash incentives. This has lead to 81 new ventures and has apparently been the source of the 1,000 new jobs mentioned by the Minister of Economic Affairs. The annual European Satellite Navigation Competition and Galileo Masters competition have also generated a whole bunch of ideas and concepts (8,000), some of which have found support through this incubation process.
Airbus Defence gave a short overview of the testing work it accomplished in supporting the first Galileo fix and has prepared several vehicle test platforms, ready to take the next phase of Galileo testing to the streets in realistic, real-world environments.
DLR provided insights into a number of its activities, namely:
Iono mapping
Signal distortion
Multipath
Jammer mitigation – adaptive antenna and processing
GNSS repeaters – how they can become unintentional jammers
Spoofer and Multipath inbvestigations
Antenna designs
GNSS evolution – Maser and clock combination benefits
Army University of Munich discussed radio science experiments in the Solar System and experiments using Mars Express (above) in polar orbit around Mars and resulting measurements of the moon Phobos. Internal and external outreach efforts with numerous organizations were also mentioned.
IFEN provided more down-to-Earth information on the on-going activities at the GATE ground-based pseudolite range, which has enabled realistic outdoors testing of Galileo receivers, well in advance of signals from orbiting satellites. Recent testing has now been able to include the four operating Galileo SVs on orbit with GATE pseudolite signals. GATE will continue to evolve over the next few years to keep up as more Galileo orbital signals come on-line.
Fraunhofer presented information on its 40-channel GPS/Galileo/GLONASS chip-receiver (above) – claiming 1-meter accuracy, low-cost, robust reliable position solution, small form-factor and low-power. Following PRS test-bed development efforts, Fraunhofer has now received a contract to also deliver 20 pre-operational Galileo PRS receivers for use in initial pilot projects.
GNSS Interference
Vidal Ashkenazi, in his inimitable form, lead a panel discussion on interference, jamming (in particular Personal Privacy Devices, or PPD) and spoofing, and coaxed his panel members to provide a whole bunch of information on what’s being done, mitigation capabilities and potential enforcement. Unlike all the other sessions, Vidal’s panel members didn’t use presentations, but rather responded to wide-ranging questions on the subject from the session chair.
David Turner, representing the U.S. State Department, indicated that the ICG will meet shortly in Geneva hosted by the International Telecommunication Union (ITU) to focus on interference, jamming and mitigation. The recourse that nations have for use of PPDs by their people is the law — jammers are illegal, sale and purchase of them is illegal — however, Internet sales are very difficult to police. So detection and mitigation are required to find and shut them down. Dave’s presentation on the GPS.gov website indicates that the ICG is working on an education program for states to inform about GNSS sensitivity to interference and the threat to critical infrastructure if they are allowed to operate. The ICG also has a task force on detection, reporting and systems development.
ISRO indicated that PPD jammers in India are restricted, but permitted for gatherings such as at churches where personal safety may be an issue. Ground-based detection is needed, as well as stronger legal protection that may well prohibit use of PPDs altogether.
Japan Aerospace Exploration Agency (JAXA) indicated that it is working on “signal proofing” for QZSS.
BeiDou said it is building a monitor network in China that will detect jamming.
There was a general discussion on whether receiver manufacturers should be mandated to make receivers that are resilient to jamming – many thought that there have already been significant advances in that direction by manufacturers. The normal approach would be to develop requirements with industry, agency and user inputs, publish them, and call up the requirements in equipment specifications. In the U.S., the Department of Homeland Security is seeking an approach to detection and location.
Legal Impacts of Personal Privacy Devices (PPDs)
While the audience may have had high hopes that the legal eagles could come up with some magic prevention and prosecution solution, the next session was more of a legal background briefing without any concrete conclusions (quite similar to other discussions I’ve had with some lawyers in the past, actually).
The first briefing was from the European Commission/European Union, who indicated that the EU doesn’t own the frequency rights to Galileo (Oh Oh…). They have to operate through a member state, which gets the rights through the International Telecommunication Union (ITU) and then licenses use to the EU — the bottom line being that EU enforcement of jamming protection laws maybe be difficult, as the legal framework only exists at the national level for each state. The EU is trying to get recognition under another class of ITU membership.
EU regulations were presented that state that GNSS re-transmitters can only be operated legally by governments or government contractors. Or can be used indoors for indoor navigation, but only for emergency services at fixed sites which are pre-approved. Pseudolites can only be operated indoors, and there should be no interference to other systems. Jammers are forbidden and cannot be placed on the market for sale.
Eurocontrol had a lot to say about the impact on aviation navigation infrastructure and receivers on aircraft. Existing ground nav aids have limitations, the worldwide equipment infrastructure is becoming quite old — aviation has generally moved away to GNSS and inertial based navigation and uses ground navaids as backup. There is a conflict between regulating GNSS heavily for aviation and how people want to use it in the commercial world. We may have to consider a trade-off between heavily restricted GNSS operations, and wide open commercial GNSS applications.
David Sobel, from Electronic Frontier Foundation in the U.S., presented the contrary case for individual privacy. His argument is that sale of tracking devices is unregulated and can readily be purchased, so people may presumably use them to track others, thereby infringing their privacy. So why shouldn’t people be able to “defend their privacy” by use of PPDs?
Say an employer insists that a vehicle you are driving have a tracking device so he knows where you are. Isn’t the driver also justified in trying to protect his privacy? Since the police in the U.S. can no longer place tracking equipment on suspect vehicles without a warrant, tracking appears to be down to private individuals or companies, who it would appear, have the legal ability to attach tracking devices under most circumstances. So the argument goes that if people have a legitimate concern about privacy, there should be acceptable provisions to allow them to disrupt tracking.
If there is a service such as road tolling, there is an incentive for people to avoid these costs. So systems should be robust enough to avoid disruption. Enforcement is a problem — should police chase people they suspect have jammers, or should they rather chase criminals or help and protect citizens? Mitigation systems need testing, so to test these systems there has to be jamming transmission — which needs to be controlled and regulated. Restricting the import of bad devices into a country might be desired, but the manufacturing countries don’t tend to want to restrict exports as exports help their economy. Again, the argument seems to be that of personal privacy over potential risks and damages to society.
No solutions, but a healthy discussion of views from a legal perspective.
Precise Point Positioning (PPP)
The group discussing PPP options consisted of the GSA (charged with exploitation of Galileo services), several principle industry service providers of PPP, and the federal agency, which provides PPP-like services in Germany.
The GSA presented its ideas concerning the provision of high-accuracy PPP corrections over the Galileo E6 signal – the so-called Commercial Service (CS). The intent, however, would not be to disrupt the commercial marketplace. Nevertheless, GSA is proposing a public-funded service to be sold to users within a market that is already well served by commercial worldwide service providers who charge users for cm-level PPP service.
And while Trimble made a polite presentation on the many levels of capabilities of its TerraSat services, as did Veripos and to some extent Fugro, it was clear that the commercial providers are not eager to find competition in their market from a government entity. NovAtel also chimed in on this conflict as it will be involved in Veripos/TerraStar, following its acquisition by Hexagon. Fugro appeared to be interested in acquiring rights to distribute CS on behalf of GSA.
The German Federal agency promoted open data, source and standards from the IGS network to which it contributes: IGS is supported by numerous national agencies around the world. Orbit and clock PPP service is available 24/7 from multiple sources. However, the service is offered on a best efforts basis without a service guarantee, and cannot achieve the accuracies or convergence times of commercial services.
I talked subsequently with Michael Ritter, CEO of NovAtel, to learn the background to the Veripos/TerraStar acquisition. It’s clear that providing PPP services means added value to NovAtel when they sell receivers with PPP capability, so they will quickly discontinue offering Omnistar subscriptions and will shortly launch NovAtel Correct, offering Veripos (marine) and TerraStar (land) PPP subscription services. NovAtel is making significant inroads in the agriculture segment, and they see PPP service as an essential element of this and other businesses. The acquisition was worth something on the order of $200 million, so there is a vested interest in making these services pay and discouraging GSA entry into this market. Veripos will continue supplying other GNSS OEM receiver manufacturers — notably Septentrio, who use TerraStar services, now also NovAtel, and potentially another major GNSS manufacturer.
Future of GNSS in User Segment
Chaired by Greg Turetzky of Intel, this session opened the third day of the Summit. The presenters offered their concepts for current and future GNSS equipment and systems.
Stanford University outlined its work with FAA on an alternate PNT system to be used as a back-up to GNSS. It used to be that GNSS systems were designed to overcome space-weather effects and faults in equipment design or manufacture — nowadays, there are “bad guys” out there and we need to “protect, toughen and augment” these systems. Antennas can be built that impart a specific signature to the signals they transmit, and this may aid in finding and prosecuting the bad guys, but the main focus of work is development of a hybrid system using Distance Measuring Equipment (DME) and a pseudolite.
Tests have demonstrated good performance, and these prototype efforts could lead to aviation requirements (MOPS) development by 2018 and deployment by 2020.
Septentrio has been involved in Galileo since it began and was the first company with Galileo receivers. Nowadays, they have receivers fielded in multiple commercial applications, including machine control, maritime, aviation, automation, and measurement, delivering accuracies from a meter down to a centimeter. They will add E6 to their AsteRx family of multiple-channel, multi-frequency, multi-constellation receivers, and have developed a number of hardware and software mitigation techniques to combat jamming, interference and multipath, and to integrate receivers with inertial units for aiding.
Furuno is interested in resilient PNT for marine applications, and has examined the use of eLoran as an alternative to GPS, but has moved towards a system of radar beacons that detect radar pulses from passing ships and transmit their positions, enabling position determination. In tests, accuracies of around 2 meters have been obtained with two beacons.
Quascom’s approach is to add firewalls inside receivers, which toughen the processing and prevent distortion of position information. Quascom believes this will be necessary until authentication can be added into the GNSS system itself, so that any data received is validated and is known to be good.
Chris Rizos from the University of New South Wales, Australia, drew attention to the “holes” that exist in GNSS, and reviewed a number of possible “Band-Aid” fixes, such as Wi-Fi especially for indoor location. However, his solution seems to be to establish terrestrial networks transmitting GNSS-like signals.
Eurocontrol indicated that aircraft currently use inertial and DME extensively as a back-up to GNSS navigation. By 2030, there will be multiple constellations, and dual-frequency use should become commonplace in aviation, so GNSS navigation should be much more robust. Aircraft approaches are required to be in conformance with Required Navigation Performance (RNP), so would it be possible to develop RNP procedures for DME and inertial to be used as back-up during approaches in the event GNSS is disrupted?
To conclude the session, Airbus provided a “starter course” overview on inertial systems – how they work, the range of different types available, what they can achieve, costs, strengths and weaknesses and integration with GNSS.
The summit continued with subsequent sessions on:
Space technologies and users
GNSS monitoring of Earth and disaster management
Copernicus – Earth Observation
GNSS Education
Unfortunately, my deadline didn’t allow me to attend these equally interesting presentations.
There is also a manufacturers’ exhibit area at the summit that just fits into a couple of corridors near the main hall – around 20 booths. I talked with several of the manufacturers, including Spirent who has launched its latest GSS9000 multi-frequency-constellation simulator, with a four-fold increase in system iteration rate over the previous model. Exhibitors appeared to be pleased to be at the summit and by the level of interest shown by the attendees.
So, as this year’s Munich Summit concludes, where does this leave us? We’ve learned some new things about several GNSS topics and heard some interesting new concepts. Europe appears to be now focused on users and applications, to ensure there is market growth and use of Galileo. What stands out for me is the contrast between how European governments go about GNSS and how North America and the commercial world does the same thing without as much direct influence. This is nothing new, of course, it’s just the European way…
Plans to harness Galileo and other satnav systems for next-generation satellite augmentation systems for aviation and other high-performance uses took a significant step forward at the latest gathering of worldwide operators and experts, reports the European Space Agency.
Satellite augmentation systems combine additional ground stations and satellite transponders to sharpen satnav accuracy and reliability across given geographical regions — based on the U.S. GPS for now, but with plans to move to a multi-constellation design additionally employing Europe’s Galileo, China’s BeiDou, and Russia’s GLONASS systems in the post-2020 era.
The 26th Satellite Based Augmentation Systems (SBAS) Interoperability Working Group (IWG) took place in New Delhi, India on February 5–7.
The 26th SBAS Interoperability Working Group (IWG) was introduced by V. Somasundaram, board member of the Airport Authority of India.
Among its achievements was to converge on a standard message definition for one of the channels — known as L5 — of the planned second-generation SBAS systems, which will utilize dual-frequency, multi-constellation signals.
“Two solutions had been put forward, one by ESA based on work by European industry and one from the U.S. Federal Aviation Administration and Stanford University,” explains ESA’s Didier Flament, co-chair of the IWG.
“A single definition coordinated between both bodies has been presented, combining the benefits of both solutions. The formal IWG review and approval loop has now been started with the objective of finalizing it for September’s IWG meeting.
“The aim is to have it ready to submit to the official international SBAS standardization bodies — the International Civil Aviation Organization and the Radio Technical Commission for Aeronautics — as soon as October.”
The meeting also marked the significant progress made by Indian’s own SBAS system GAGAN, which underwent its final stability test last summer, followed by its safety certification in December.
At this point GAGAN was declared certified for non-precision approach users , followed by its safety-of-life service being formally offered to civil aviation users on 14 February.
GAGAN has been jointly undertaken by the AAI and the Indian Space Research Organisation, intended to provide improved accuracy, availability and integrity necessary to enable users to rely on satnav signals for all phases of flight – from en route as well as approach to all qualified airports within the GAGAN service area.
SBAS services worldwide
EGNOS is an operational precursor to Europe’s Galileo global satnav system.
GAGAN is the fourth certified SBAS to enter servicer worldwide. Europe has the European Geostationary Navigation Overlay Service (EGNOS), which was designed and built by ESA then turned over for operation by the European Satellite Service Provider, ESSP, overseen by the European Global Navigation Satellite System Agency (GSA) — both of whom also participated in the meeting. ESA retains responsibility for the future evolution of EGNOS.
The U.S. has the Wide Area Augmentation System (WAAS), developed and operated by the Federal Aviation Administration, with an extension over Canada called CWAAS (Canadian WAAS). WAAS celebrated its 10th anniversary of operational life last July.
Japan has the Multi-functional Satellite Augmentation System (MSAS), developed and operated by Japan’s Civil Aviation Bureau. Japan is currently discussing plans to merge this capability with their new home-grown satnav system, QZSS.
Along with GAGAN, the meeting also covered the progress made by the other SBAS systems under definition or development — the Russian SDCM, Chinese SNAS and Korean K-SBAS.
The follow-up IWG meeting is due to take place in September in Tampa, Florida.
Planned GAGAN service coverage for the two different service levels (RNP0.1 and APV1). GAGAN has been jointly undertaken by the Airport Authority of India and the Indian Space Research Organization, ISRO, to achieve smooth transition to satellite-based navigation and seamless air traffic management across continents. GAGAN is designed to provide improved accuracy, availability and integrity necessary to enable users to rely on GPS for all phases of flight, from en route through approach for all qualified airports within the GAGAN service volume. More precisely it is aimed to provide Non Precision Approach RNP0.1 service levels to the entire Indian Flight Information Region and Precision Approach APV1 service (equivalent to the current EGNOS Service) within a specified service volume within Indian land mass.
Tackling ionospheric interference
The New Delhi IWG took place concurrently with a related meeting, the ICAO’s 4th Ionospheric Study Task Force. This group has been tasked with the objective of developing region-specific models of ionospheric models to compensate for satnav signal interference or loss.
The ionosphere, the electrically sensitive outer shell of Earth’s atmosphere, can be perturbed by solar activity. And because satnav signals pass from space by Earth they can then be disrupted in turn. Equatorial regions see the greatest disturbance, including signal delay or ‘scintillations’ making signals unstable.
The aim is to develop reliable ionospheric models to compensate for these effects, particularly for equatorial SBAS regions, such as India. ESA is contributing with data from its worldwide Monitor network, gathering data to improve future EGNOS performance and potentially support further geographical extension.
Comparing current worldwide SBAS coverage — based on WAAS, EGNOS and MSAS — to the situation envisaged for 2020–25: near-global coverage based on WAAS, EGNOS, MAAS, SDCM and GAGAN, with an expanded network of stations in the southern hemisphere, based on a common dual-frequency/dual satnav standard being finalized by the SBAS IWG.
The Director General of Civil Aviation (DGCA) of India certified on December 30 the GAGAN system to RNP0.1 (Required Navigation Performance 0.1 Nautical Mile) service level, according to The Hindu.
Now aircraft equipped with Satellite Based Augmentation System (SBAS) receivers will be able to use GPS-Aided Geo Augmented Navigation (GAGAN) signals in Indian airspace for en route navigation and non-precision approaches without vertical guidance.
Mission control centers, along with associated uplink stations, have been set up at Kundalahalli in Bangalore. Another control center and uplink station are in Delhi. A top official of the AAI said one of the Reference Stations has been housed outside the premises of the Thiruvananthapuram airport. The reference stations pick up signals from the orbiting GPS satellites. The measurements are immediately passed on to the mission control centers that then work out the necessary corrections that must be made. Messages carrying those corrections are sent via the uplink stations to the satellites in geostationary orbit that have the GAGAN payload.
The availability of the GAGAN signal in the country’s air space will bridge the gap between European Union’s European Geostationary Navigation Overlay Service (EGNOS) and Japan’s Multi-functional Satellite Augmentation System (MSAS) coverage areas.
The SBAS consists of 15 Indian Reference Stations, three Indian Navigation Land Uplink Stations, three Mission Control Centers, three Geo-Stationary Navigation Payload in C and L bands and with all the associated software and communication links.
GAGAN will provide augmentation service for GPS over India, the Bay of Bengal, South East Asia and the Middle East expanding up to Africa.
JAVAD GNSS has commented on some news that its receivers can track a new L5 signal from the Indian SBAS satellite, GSAT-8, launched on May 20. In a further explanation to GPS World, CEO Javad Ashjaee explained, “All owners of our products can track it. The only thing is that if customers have not updated their firmware for a long time, they should update to recent firmwares released earlier. They need to update their firmware, which is free of charge and is posted on our website. All of our customers with recent firmware versions can track the GAGAN L5 signal.”
An earlier report from CANSPACE that appeared on the GPS World website said, in part, “Although GSAT-8 reportedly carries a dual-frequency transponder, no L5 signals from this satellite have yet been detected by International GNSS Service tracking stations.”
The JAVAD GNSS statement on September 30 said “Report of GPS World that GAGAN PRN127 does not transmit L5 signal is not correct. Our receivers track it. This graph shows code-phase measurements for this signal.” The web page displays this figure:
A check with a University of Bern, Switzerland, report of stations participating in the IGS M-GEX campaign on October 2 found that a number of stations are tracking the L1 signal from GSAT-8 but none are tracking the L5 signal yet due to issues with receiver firmware. However, various stations in the Cooperative Network for GNSS Observation (formerly the Cooperative Network for GIOVE Observation, still abbreviated CONGO), using Javad Triumph receivers, have tracked GAGAN L1 and L5 signals for more than half a year. No detailed analysis of these measurements has been performed so far.
The Indian Space Research Organisation’s GSAT-10 geostationary communications satellite was launched from the European spaceport in Kourou, French Guiana, on 28 September at 21:18 UTC. The dual-satellite launch also carried the Astra 2F direct-to-home broadcast satellite into orbit for Luxembourg-based operator SES.
GSAT-10 contains a payload to support the Indian GPS and GEO Augmented Navigation (GAGAN) satellite-based augmentation system. The satellite will likely use PRN code 128 from its orbital slot at 83 degrees east longitude.
NORAD/JSpOC is tracking four objects from the launch, all in geostationary transfer orbits:
The two satellites are accompanied by the Sylda 5 dual-payload adapter and the ESC-A upper stage of the Ariane 5 launch vehicle. It’s not yet known which objects are which.
Once GSAT-10’s GAGAN L-band payload is activated, the satellite will be tracked by stations of the International GNSS Service’s Multi-GNSS Experiment in addition to those of the official GAGAN monitoring and control network.
The following is from a press release issued by ISRO:
“ISRO’s Master Control Facility (MCF) took over the command and control of the GSAT-10 immediately after the injection. Preliminary health checks on the various subsystems of the satellite, namely, Power, Thermal, Command, Sensors, Controls, etc., were performed and all the parameters were found satisfactory. Following this, the satellite was oriented towards the Earth and the Sun using the onboard propulsion system. The satellite is in good health.
“In the coming five days, orbit raising maneuvers will be performed to place the satellite in the Geostationary Orbit with required inclination with reference to the equator. The satellite will be moved to the Geostationary Orbit (36,000 km above the equator) by using the satellite propulsion system in a three step approach.
“After the completion of orbit raising operations, the two solar panels and both the dual gridded antenna reflectors of GSAT-10 will be deployed for further tests and operations. It is planned to experimentally turn on the communication payloads in the second week of October 2012.
“After the successful completion of all in-orbit tests, GSAT-10 will be ready for operational use by November 2012. GSAT-10 will be positioned at 83deg East orbital location along with INSAT-4A and GSAT-12. The operational life of GSAT-10 is expected to be 15 years nominal.
“GSAT-10 Satellite has 30 Communication Transponders [12 in Ku-band, 12 in C-band and 6 in Extended C-Band]. Besides, it has a Navigation payload “GAGAN” that would provide GPS signals of improved accuracy (of better than 7 meters) to be used by the Airports Authority of India for Civil Aviation requirements. GSAT-10 is the second satellite in INSAT/GSAT constellation with GAGAN payload after GSAT-8, launched in May 2011.”
India’s GSAT-10 telecommunications satellite — one of two passengers for Arianespace’s upcoming Ariane 5 mission in September — has been put through its paces during pre-flight preparations at the Spaceport in French Guiana, including a solar panel deployment test, according to Arianespace.
Also 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. The initial GAGAN payload was carried aboard the GSAT-8 spacecraft, orbited by Arianespace on an Ariane 5 mission in May 2011.
The solar panel checkout involved the extension of its multi-segment solar panels, validating the proper operation before they are definitively stowed against the satellite in the final lift-off configuration. The test uses an overhead latticework that helps support the solar panel’s weight — simulating zero gravity conditions of space as the panel opens to its full length.
Performed under the control of GSAT-10 satellite team members, the extension validation was conducted in the S5C high bay area of the Spaceport’s S5 payload preparation center — the largest individual hall in this facility.
GSAT-10 was developed by the Indian Space Research Organisation (ISRO), and will meet the growing need for Ku- and C-band transponder capacity. It is to become part of the Indian National Satellite (INSAT) system of geostationary spacecraft — representing one of the largest domestic communications satellite networks in the Asia-Pacific region.
Configured with 12 Ku-band, 12 C-band and 12 extended C-band transponders, GSAT-10 utilizes the I-3K satellite bus developed by ISRO, with a power capability of some six kilowatts and a liftoff mass estimated at 3,400 kg.
The upcoming Ariane 5 flight with GSAT-10 and the Astra 2F satellite as its co-passenger is set for September 21 from the Spaceport’s ELA-3 launch
complex. This will be Arianespace’s fifth mission from French Guiana in 2012 with the heavy-lift workhorse.
Below, one of GSAT-10’s two solar panels is extended during deployment verifications performed in the Spaceport’s S5 payload preparation center.
Look back with me at the five 2010 GNSS events that most affected surveying, mapping, engineering, construction, and natural resource users. Each one had, or could have had, a significant effect on you and your work. Taking it from the top:
GPS 24+3 Constellation. The most important event occurred a year ago, when the Air Force began implementing a new GPS 24+3 configuration. They had their military reasons, but the benefit for you and me is eliminating GPS brownouts — periods with fewer GPS satellites in view. When combined with obstructions such as terrain, trees, or buildings, they made GPS hard to use.
It’s especially an issue with real-time kinematic (RTK) high-precision users because RTK technology is satellite-hungry. It needs six or more satellites to provide a robust position solution.
The Air Force moved three satellites, SVNs 24, 26 and 30, from their original slots. SVNs 26 and 30 have already reached their destinations, and SVN 24 will do so this month.
Three other satellites are being shifted slightly. SVN 55 found its new slot in December, while SVNs 46 and 56 start this month and should have completed their journeys by May/June 2011.
By now, you should be seeing some improvements in GPS satellite visibility. Although you’ll see fewer peaks (high number of GPS satellites in view), you’ll also see fewer valleys (low number of GPS satellites in view). This should increase productivity for RTK users and those in obstructed environments such as tree canopy.
First GPS Block IIF. Although it doesn’t really help users at this point other than being another satellite to enter service, the Block IIF satellite launched in May is the first to broadcast the third civil signal. L5 marks the beginning of a new era in high-precision GPS positioning. The Block IIF launch was the catalyst for my June column “What Happen When High Accuracy is Cheap?”
This IIF is just a teaser though, and its fellows will launch at a snail’s pace. Remember though, it costs upwards of $200 million to launch a satellite and since there ares already 30+ operational GPS satellites in orbit, it’s hard for Congress and the Air Force to justify speeding up the launch schedule. The last target I heard was to have 24 satellites broadcasting L5 by 2019.
GLONASS Growth. Despite the recent catastrophe, the Russian Federation was still able to launch seven new satellites in 2010, including a new K1 satellite that will test a new CDMA signal for better compatibility with GPS.With 21 operational satellites and three more coming in March, a consistent and healthy number of GLONASS satellites in orbit has given receiver manufacturers more confidence to develop GPS/GLONASS receivers. This year, we’ve seen several manufacturers integrating GPS/GLONASS into handheld receivers as well as OEM board products.
User benefits are clear: more robust positioning and improved productivity due to decreased down-time.
Solar Activity. The big news is no news: the sun was eerily quiet in 2010. If your GPS receiver didn’t work at times this year, it wasn’t due to solar activity. But it may ramp up in 2011.
GAGAN, WAAS Failures. The Indian Space Research Organisation and the U.S. Federal Aviation Administration received a hard lesson in SBAS GEO management. In April, an Indian rocket launch failed, and one of the FAA WAAS satellites lost communication with its ground control.
If you’re an SBAS user, don’t let it bring you down. SBAS is here to stay, and likely you were not affected by either incident — unless you work in northwest Alaska. A new U.S. SBAS satellite came online, and India is regrouping for more launches.
A new draft policy in India seeks to foster global use of its Indian NavIC satellite navigation system. The draft Indian Satellite Navigation Policy 2021 (SATNAV Policy 2021) is part of reforms of the Indian Space Research Organisation (ISRO)/Department of Space (DoS).
