Category: BeiDou

  • China to launch 11 more BeiDou-3 satellites this year

    China will launch 11 more BeiDou-3 satellites by the end of 2018, according to the Xinhua News Agency, the official state-run press agency.

    China has already launched eight BeiDou-3 satellites for its domestic BeiDou Navigation Satellite System. The satellites will provide initial services for countries and regions along the Belt and Road by the end of the year, said Wang Li, chairman of the China Satellite Navigation System Committee.

    Addressing the Ninth China Satellite Navigation Conference in Harbin, capital of northeast China’s Heilongjiang Province, Wang said the BeiDou system is moving to become a global service provider after offering stable and reliable time and space information for clients in the Asia-Pacific region.

    China launched the first two BeiDou-3 satellites into space via a single carrier rocket in November 2017, as its self-developed BeiDou system officially began to expand into a global network.

    Compared to earlier generation satellites, the BeiDou-3 is able to send signals that are more compatible with other satellite navigation systems and provide satellite-based augmentation, as well as search-and-rescue services in accordance with international standards. Its positioning accuracy has reached 2.5 to 5 meters.

  • Harxon exhibits positioning, data-transmission tech at AUVSI Xponential

    Harxon exhibits positioning, data-transmission tech at AUVSI Xponential

    Harxon showcased high-precision positioning GNSS antennas and its latest wireless data-transmission technologies for UAV applications at AUVSI Xponential, which was held April 30-May 4 in Denver.

    The Harxon D-Helix Antenna.

    Harxon’s D-Helix is a patented D-QHA (dual-quadrifilar helix antenna) multi-constellation antenna supports excellent reception of GPS, Galileo, BeiDou and GLONASS, as well as L-band signals. Harxon D-QHA technology ensures the ability of low elevation satellites tracking while maintaining 4-dBi high gain, which makes the D-Helix antenna an excellent choice for any applications where the sky is partially visible, the company said.

    The antenna’s low noise amplifier (LNA) with out-of-band rejection performance can suppress electromagnetic interference. Moreover, the D-Helix features the latest low wind resistance design with ruggedized IP67 protection for UAV inspection and monitoring, survey and mapping or agricultural UAVs.

    Photo: Harxon
    Photo: Harxon

    The HX-DU2017D is a 5-gram frequency-hopping OEM transceiver supporting frequencies between 840 MHz and 900 MHz. It provides strong anti-jamming and signal receiving capability for complex data intensive applications. Its full duplex mode ensures data secure transmission, more stable long-range communication and short latency of data transmission.


    Watch this video to learn more about the HX-DU2017D.


    Other showcased Harxon GNSS products, such as Helix Antenna HX-CH7603A, HX-CH4601A and HX-CH6601A, are all featured with patented D-QHA technology. Moreover, the showcased Survey Antenna GPS 500, OEM Modem HX-DU1018D and Smart Antenna are also appropriate for surveying and mapping, as well as precision agriculture.

    Photo: Harxon
    Photo: Harxon
  • BeiDou/GLONASS merger mystery

    Contrary to the “Out in Front” editorial published in the April issue of GPS World magazine, there was an Izvestia story published on March 28 touting the possibility of a merger of the GLONASS and BeiDou systems, and there will be an International Conference on Advanced Technologies in Manufacturing and Materials Engineering in Harbin, China, at which such a possibility may hypothetically be discussed.

    However, neither hard news nor any official statements have emerged to substantiate such a dubious claim, despite repeated queries to officials of both countries.

    Javad Ashjaee (far left, above), CEO of JAVAD GNSS and based in Moscow, communicated that he spoke on a panel at an aerospace technology event organized by the American Chamber of Commerce in Russia, alongside representatives from NASA, Boeing, Honeywell and Roskosmos.

    Ashjaee asked the Roskosmos official publicly about the prospect of a GLONASS merger with BeiDou, and “he knew nothing.”

  • System of Systems: The long life of GPS III

    System of Systems: The long life of GPS III

    Late Breaking: Ligado

    On April 26, the U.S. Department of Transportation publicly released the long-awaited GPS Adjacent Band Compatibility Assessment. See the June issue of GPS World for an expert and measured analysis of this highly impactful document.

    The article will be posted online when it becomes available in mid-to-late May.


    Merger Mystery

    Contrary to the “Out in Front” editorial published in the April issue of GPS World magazine, there was an Izvestia story published on March 28 touting a merger of the GLONASS and BeiDou systems, and there will be an International Conference on Advanced Technologies in Manufacturing and Materials Engineering in Harbin, China, at which such a possibility may hypothetically be discussed.

    However, neither hard news nor any official statements have emerged to substantiate such a dubious claim, despite repeated queries to officials of both countries.

    Javad Ashjaee (far left, above), CEO of JAVAD GNSS and based in Moscow, communicated that he spoke on a panel at an aerospace technology event organized by the American Chamber of Commerce in Russia, alongside representatives from NASA, Boeing, Honeywell and Roskosmos.

    Ashjaee asked the Roskosmos official publicly about the prospect of a GLONASS merger with BeiDou, and “he knew nothing.”


    Diverger Dilemma

    As this magazine goes to press, stories emerge of a U.K. plan to launch a satellite-navigation system separate from the European Union’s Galileo project. This comes in response to an EU statement that the UK would be shut out of key elements of the European satnav program, particularly the Public Regulated Service, after Brexit.

    Historically, in the late 1980s or early 90s the UK drew up plans for its own GNSS prior to the launch of Galileo. And UK-based Surrey Satellite Technology Ltd. built all operational Galileo payloads to date. So the country clearly has the capability. That SSTL is currently owned by Airbus (either German or Dutch division) may or may not constitute a wrinkle.

    Finally, the UK spent 1.4 billion euros on Galileo, and may now file for a refund.


    The Long Life of GPS III

    By Robin Wrinn, Contributing Author

    GPS III SV01 in electromagnetic interference, compatibility and passive intermodulation testing. (Photo: Lockheed Martin)

    During interviews with Lockheed Martin and Harris Corporation at the 34th Space Symposium, time and space were a frequent focus of discussion, but not in the normal “continuum” kind of way.

    Greater mission longevity is one of the key improvements GPS III delivers over those currently in service. Space Vehicles 1–10 have a planned mission life of about 15 years, 25 percent longer than their predecessors. Yet that begs the question “How long should a satellite live in space, with technology innovation occurring almost annually?”

    Advanced payload technology provides a partial answer to that question. Both Lockheed Martin and Harris Corporation highlighted new payload capabilities with built-in flexibility to adapt satellites in orbit to technology advances, as well as changes in missions.

    Lockheed Martin provided the media a tour of their Radio Frequency Payload Center of Excellence. Meanwhile, Harris recently announced completion of the fully digital Mission Data Unit (MDU), core to the navigation payload for GPS III 11 +. As a reminder, the current Harris payload for SVs 1–10 includes:

    • greater than three times reduction in range error,
    • up to eight times increase in anti-jamming power,
    • added signals, including L1C, compatible with other GNSS such as Galileo, and
    • greater signal integrity.

    According to Harris, the fully digital navigation payload will provide the ability to change and upgrade the satellites incrementally over mission life.

    Meanwhile, Lockheed announced a partnership with NEC to introduce artificial intelligence for computer learning in orbit. The company’s Payload Center experts touted significant advances in processers and a move toward next-generation antennas, arrays and transmitters to drive more satellite flexibility, capability and resilience.

    Observation: The market pressures of ‘new space’ players is prompting delivery of products that can drive more value for less cost. In this case, delivery of a common payload architecture and electronically steered beams to make satellite antennas become any shape you want. Most likely, beams of a different size on demand is a much better business case than a static one built five years ago.

    The day I interviewed Lockheed Martin’s Navigation Systems mission area Program Manager Johnathon Caldwell, the company had submitted its proposal for the U.S. Air Force’s GPS III Follow On (GPS IIIF) program. That same day, April 16, the media was given a tour of Lockheed Martin’s GPS III satellite assembly floor. It was clear from both Lockheed’s press materials and Caldwell that Lockheed Martin believes it is fully recovered from prior production hiccups and is

    • on track to deliver GPS Space Vehicles (SVs) 1 through 10, and
    • deserves to win the bid for GPS IIIF. Now that both Boeing and Northrop Grumman have dropped out of the running, Lockheed is virtually assured the contract. The government has said it will announce the award in March 2019.

    For an update on GPS III space vehicles 1–10, see the full version of this article.

    Harris Corporation Interview

    with Jason Hendrix, PNT Program Director

    What are the differences in the GPS III satellite payloads that were instituted to enable the new signals?

    The main difference is the power. The Air Force’s requirements called for significantly more anti-jamming capability. All the transmitters are a higher power.

    What was the most significant obstacle (or top obstacles, plural) in designing and manufacturing this new payload, to new Air Force specifications? How did you overcome it/them?

    Same answer really, the higher power. Keeping in mind, we went from a 7-year mission life requirement to a 15 year. That higher power puts more strain on components and new cyber requirements in software. When you couple all that together we are not just upgrading payload technology. It is really engineering a new set of payload requirements. It’s new generation, advanced.

    What are the advantages of a digital payload over the alternative?

    The advantages and the 30 percent difference are the timekeeping system portion. We’re moving from a manual, analog timing to digital to deliver to the Air Force more flexibility. It’s a nice option to have to be able to reprogram in orbit and maybe enhance capabilities desired in the future.

    For more from Harris, see longer version.

    Interview with Lockheed Martin

    with Johnathon Caldwell, Navigation Systems Mission Area Program Manager

    Any changes in your production approach having completed SV01?

    No, the performance on Vehicle 01 was as designed there were no technical or design changes necessitated throughout the rest of the fleet. So, it was a very successful from that perspective — from the standpoint of validating the design and wringing it out, Vehicle 01 served its purpose well.

    It had a very good T-Vac. I would say overall when you look at the industry, Vehicles 01–02, our vacuum test campaigns are the most rigorous test. Both went through their tests quite well. Some of the best I’ve seen.

    For more from Lockheed Martin, see longer version.

  • Dubious claim about GLONASS-BeiDou ‘merger’

    Dubious claim about GLONASS-BeiDou ‘merger’

    On April 1 — there’s a telling date for you — the Russian news outlet RT published a story headlined, “Russia and China to merge satellite tracking systems into one global navigation giant.”

    “If successful,” the story elaborated, “the project will divide the entire world into two zones of influence by two united systems: GLONASS-BeiDou and GPS-Galileo, operated by the U.S. and the European Union.”

    Intriguing. Mind-boggling. With some initial smattering of verisimilitude.

    I don’t want to say, “Yet in the end, spurious.” Because we haven’t yet reached the end. But indicators point in that direction.

    What. The story claimed that “The countries will reportedly negotiate the merger in May at the International Conference on Advanced Technologies in Manufacturing and Materials Engineering in the Chinese city of Harbin, Izvestia daily reports.”

    The primary reason for all GNSS and for GPS itself in the very beginning is military advantage. For these two superpowers in particular to share one military resource is unthinkable; for either to disclose aspects of its security and weapons guidance operations to the other, untenable.

    Whence. Who is RT? According to Wikipedia, the outfit formerly known as Russia Today is an international television network funded by the Russian government, operating cable and satellite television channels and internet content directed to audiences outside of Russia. Based in Moscow, it presents around-the-clock news providing “a Russian viewpoint on major global events.” In 2008, Prime Minister Vladimir Putin included RT’s parent organization on a list of core organizations of strategic importance to Russia.

    RT has been frequently described as a propaganda outlet for the Russian government and its foreign policy, and has been accused of spreading disinformation, broadcasting “materially misleading” content. In 2017, during the French presidential election, a spokesperson for successful candidate Emmanuel Macron said that both RT and the Sputnik news agency showed a “systematic desire to issue fake news and false information,” and banned them from campaign events.

    Why. No one to whom I reached out in either Russian or Chinese government or satnav operations agency has returned any comment. Silence on all fronts.

    We can only guess at the underlying reasons for this floated, unsubstantiated story. To stir things up, as has been done in other arenas by these same “news” actors. It’s just a bit stinging, and a bit scary, to find it in our own world of science and technology.

    There is no evidence that any GLONASS officials have been in any way involved — there’s no evidence of anything at all, when you come right down to it.  The development does not reflect favorably on the Russian news system, and it may be as well to take everything from Moscow with a barrel of salt until something more tangible emerges.

    A GLONASS-M satellite is prepped for launched in February 2016. (Photo: Russian Ministry of Defense)
    A GLONASS-M satellite is prepped for launched in February 2016. (Photo: Russian Ministry of Defense)
  • Lighthouse front-end processes 4 GNSS frequencies simultaneously

    Lighthouse front-end processes 4 GNSS frequencies simultaneously

    Lighthouse Technology and Consulting Co. Ltd. has developed of a series of front-end processors for GNSS software receivers.

    The Hibiki processors can take input from up to four frequency GNSS signals simultaneously.

    The Hibiki front-end can process up to four GNSS signals for software receivers. (Image: Lighthouse)

    The Japanese Quasi-Zenith Satellite System (QZSS) broadcasts GNSS signals in four frequency bands: L1, L2, L5 and L6. Similarly, GPS and GLONASS broadcast in three bands, and the European Galileo and Chinese BeiDou systems broadcast in four bands.

    However, many conventional front-ends process only two bands at the same time, and cannot be used for highly specialized applications such as processing multiple signals with different frequencies at the same time.

    The Hibiki front-end processor was designed to answer to this GNSS technology demand and is able to process up to four frequency bands simultaneously, the company said.

    Hibiki has a high data transfer rate performance using USB 3.0, stably transmitting signal data to the host computer up to 50 million samples per second. This high sampling frequency is much greater than conventional front-end processors, improving L5 signal-receiving performance and reducing multipath.

    Hibiki is available starting in April.

    Chart: Lighthouse
    Chart: Lighthouse

     

  • China launches another pair of BeiDou-3 satellites

    China launches another pair of BeiDou-3 satellites

    China continues to update the BeiDou navigation satellite system. On Feb. 12, two more navigation and positioning satellites were launched into medium Earth orbits, following the successful launch of a pair of BeiDou satellites on Jan. 11.

    A Long March 3B rocket with a Yuanzheng-1 upper stage lifted off from the Xichang Satellite Launch Center, Sichuan Province, at 13:03 local time (05:03 UTC), according to gbtimes.com.


    Stay up-to-date with our Upcoming GNSS Satellite Launches table, maintained by Richard Langley.


    The launch had been set for the same window on Feb. 10, but was delayed by the visit of Chinese president Xi Jinping to the launch site.

    Success of the mission was confirmed four hours after launch, following insertion of the satellites into their intended orbits, around 21,000 kilometers above the Earth.

    The newly launched pair are BeiDou-3 28 and 29. The satellites are part of a third phase of Beidou deployment, which will take Beidou coverage from regional to covering the countries along the Belt and Road initiative by the end of 2018, and global by 2020.

    According to Nasaspaceflight.com, the satellites are using a new bus featuring a phased array antenna for navigation signals and a laser retroreflector, with a launch mass of 1,014 kg.

    The accuracy, stability and signal strength of the Beidou-3 satellites is improved over previous versions by developments in atomic clocks, laser communications and inter-satellite links.

    The Long March 3B/YZ-1 carrying Beidou satellites 28 and 29 lifts off from Xichang Satellite Launch Centre at 13:03 local time on Feb. 12. (Photo: CNS)
  • UK government issues highest level study of SatNav vulnerabilities

    A U.K. government report issued on Jan. 30 looks at the vulnerability of all satellite-based positioning systems: GPS, Galileo, GLONASS, BeiDou, QZSS and more. Issued by the Office of the Government Chief Scientific Adviser, Sir Mark Walport, and informally called the Blackett Report, designating the highest level of government scientific studies, named after a UK physicist who won the 1948 Nobel Prize, the review aims to “lay out the breadth, scale and implications of our reliance on ‘the invisible utility’ mainly in terms of existing critical national infrastructure (CNI).”

    “Satellite-derived Time and Position: A Study of Critical Dependencies” states in the forward that it “represents a vital step in understanding the UK’s dependency on GNSS and recommends measures to improve our resilience. Importantly, it also recognises that innovation will be key to realising, fully and safely, the economic and societal benefits offered by GNSS.”

    The report points to the fragility of satellite positioning signals which can be affected by cheap jammers, spoofers, weather and interference from other radio signals — among other vulnerabilities. The 86-page PDF document is downloadable here.

    The review incorporates the results of a separate but related study, issued in April 2017, looking at the fiscal consequences of a GNSS disruption in. “Economic Impact to the U.K. of a Disruption in GNSS” was briefly summarized in a June 2017 column from this magazine (scroll down to “At What Cost Ignorance?”). The report attempted to quantify the cost of a GNSS disruption, should one occur. The authors came up a figure of 5.2 billion pounds ($6 billion) for a 5-day disruption.

    David Last, a UK consultant engineer specializing in radio navigation and communications systems, professor emeritus at the University of Bangor, Wales and past president of the Royal Institute of Navigation, consulted on the June 2017 economic impact report, and was a member of the expert panel and co-author of the January 2018 Blackett Report. He was to have given a presentation on them at the ION International Technical Meeting in Reston, Virginia on January, but could not make the trip. The following materials are drawn from his prepared presentation.

    Some of the conclusions from the June 2017 economic impact study are:

    • There are alternatives to GNSS, specific to each application
    • However, there is no universally-applicable single alternative for positioning and navigation
    • Among the most salient needs: higher quality (more expensive) oscillators for timing
    • “The most applicable mitigation strategies for the largest number of applications are eLoran and Satelles.”
    • “Omnisense and Locata may be preferred for localised applications that require high levels of accuracy.”

    From the just-issued Blackett Report, the first figure displayed above presents recommended mitigations to impacts on GNSS applications in road, rail, maritime and aviation. Alternative options include composite or hybrid navigation, terrestrial radio systems, space weather forecasting, eLoran, various methods of interference detection, multi-frequency receivers and differential GNSS.

    A second figure from Last’s presentation, shown above, covers the mitigations recommended for telecoms, finance, energy, and emergency services sectors. Mitigations for these applications include a resilient architecture with diverse network routing to high-stability atomic clocks, terrestrial radio systems, time-by-fiberoptics, multiconstellation receivers, holdover devices, GNSS integrity monitoring, and inertial navigation.

    Concluding recommendations of the Blackett Report:

    1. CNI operators to review and report on their reliance on GNSS. Cabinet Office to assess overall dependence of CNI on GNSS.
    2. Add loss or compromise of GNSS-derived PNT to National Risk Assessment, not just as a dimension of space weather.
    3. In allocating radio spectrum to new services and applications, address the risk of interference to GNSS-dependent users, including CNI.
    4. Review the legality of the sale, ownership and use of devices and software to cause deliberate interference to GNSS receivers or signals.
    5. Assess the need to monitor interference of GNSS at key sites such as ports and share the data with government
    6. Employ GNSS-independent back-up systems.
    7. Cross-government PNT Working Group to report to Cabinet Office on ways to improve national resilience.
    8. Government to facilitate as those procuring GNSS equipment for CNI specify performance standards.
    9. Map PNT testing facilities and explore how industry and critical services can better access them.
    10. Leverage UK academic and industrial expertise in time and geo-location, increasing coordination among existing centres of excellence.
  • Spirent adds BeiDou-3 to its GNSS RF simulators

    The Spirent GSS9000 simulator.

    GNSS testing solutions company Spirent Communications has added BeiDou Phase 3 signals to its GNSS RF constellation simulators.

    BeiDou Phase 3 signals are available immediately on the GSS7000 and GSS9000 simulators, and existing users can obtain the software upgrade by contacting Spirent.

    The addition of these new signals to the GSS7000 and GSS9000 simulators follows the launch of the first two Beidou-3 satellites in November 2017. Two others were launched Jan. 12.

    Phase 3 of the Chinese BeiDou system will extend its coverage from Asia to the entire world. It will provide receiver developers and integrators with additional GNSS signals to make positioning, navigation and timing systems more accurate, and help to support new applications, such as autonomous vehicles.

    The new signals will use the same carrier frequencies as the GPS and Galileo systems, so chipset manufacturers and device developers will need to test integrated designs to avoid problems caused by confusing data from different GNSS.

    “By offering the BeiDou Phase 3 signals, our customers can test their designs well before the system is fully operational, which is expected in 2020,” said Stuart Smith, lead product manager at Spirent Communications. “With signals already starting to appear, it is important for developers to have test tools that can ensure devices will successfully make use of all GNSS signals.”

    To learn more about how to test devices for multi-GNSS, Spirent offers a white paper,  “Preparing for Multi-Frequency GPS/GNSS in Consumer Devices.”

  • China launches twin BeiDou-3 navigation satellites

    China launches twin BeiDou-3 navigation satellites

    China launched twin BeiDou-3 navigation satellites into space on Jan. 12 as part of efforts to enable its BeiDou system to provide navigation and positioning services to countries along the Belt and Road by the end of 2018, reports XinhuaNet.

    China’s Belt and Road Initiative aims to create the world’s largest platform for economic cooperation.

    The pair of satellites was launched at 7:18 a.m. local time aboard a Long March-3B carrier rocket from Xichang Satellite Launch Center in southwest China’s Sichuan Province. The twin satellites are coded the 26th and 27th satellites in the BeiDou Navigation Satellite System.

    This is the first launch of the BeiDou satellites in 2018, which will see intensive launches throughout the year.

    The twin satellites are coded MEO-7 and MEO-8, the 26th and 27th satellites in the BeiDou Navigation Satellite System.

  • With Unicore, BeiDou navigates its way to global CES stage

    UM442 Module.

    With the successful launch of newest BeiDou-3 navigation satellites, Beidou’s pace of globalization is quickening. As a provider of China’s domestic GNSS core products, Unicore Communications brought its full range of products to the Consumer Electronics Show (CES), which took place Jan. 9-12 in Las Vegas.

    Unicore’s exhibits are targeting intelligent drive and the internet of things (IoT).

    UM442 Evaluation Kit: UM442-BOX2 evaluation box, navigation antenna x2

    For intelligent drive, Unicore is showcasing its UM482 high-precision GNSS module, which is designed for high-end L3 self-driving and robots.

    Unicore also is introducing a cost-effective low-power GNSS module — UM442 — which is suitable for L2 ADAS applications and community-based GNSS navigation and maps.

    UM442 is a cost-efficient high-precision real-time kinematic (RTK) and heading module that can simultaneously track GPS, BDS, GLONASS and Galileo. It also supports SBAS and QZSS.

    Based on high-performance data-sharing technology and the simplified operation system of the Nebulas II chip, the UGypsophila RTK algorithm dramatically optimizes matrix processing. Therefore, the UM442 can track many more satellites and shorten the initialization time to 5 seconds.

    Satellite view during a UM442 road test using the UGypsophila RTK algorithm. UM442 achieves centimeter-level RTK positioning using a low-cost ceramic antenna.

    With on-board MEMS and the U-Fusion integrated navigation algorithm, UM442 can achieve accurate and reliable positioning even in the most challenging environments such as urban canyons and tunnels.

    UM442 also provides attitude information such as rolling angle and pitching angle, which is suitable for many new applications such as community-based navigation maps and ADAS. Even with a low-cost ceramic antenna, the UM442 can achieve centimeter-level RTK positioning, as well as a 0.2-degree/1-meter baseline heading accuracy.

    At CES, Unicore plans to introduce BeiDou products into the large volume market of consumer electronics. Ufirebird is an ultra-small, ultra-low-power multi-GNSS positioning system-on-chip (SoC), using 28-nm technology. The chip supports BDS, GPS, GLONASS and Galileo signals, and the software can be extended to support WAAS/QZSS/EGNOS/MSAS/GANGAN enhanced signals.

    Unicore’s UFirebird-UC6226 low-power GNSS SoC is designed for mobile devices.

    Two packaging methods are available: WLCSP and QFN40. For WLCSP packaging, the chip size is only 1.73 x 2.87 mm, and for QFN40 packaging, the chip is AEC-Q100 compliant, aimed for highly reliable automotive-grade applications.

    UC6226 is equipped with a built-in sensor hub capable of providing access for multiple sensors for fusion positioning. It supports Wi-Fi, Bluetooth, GNSS hybrid positioning, and better than 1-m differential positioning accuracy.

    Compared with Unicore’s previous generation GNSS SoC, UC6226 has reduced power consumption by 60%. The minimum tracking power consumption is lowered to 18 mW, significantly improving battery endurance.

    With a built-in anti-jamming module, LNA and -162dB sensitivity, UC6226 can maintain accurate and precise positioning under complex environments.

    UC6226 has been successfully applied by China’s bicycle sharing companies. In addition, the chip will be used in intelligent watches, smartphones, smart cameras and many other IoT devices requiring smaller size, lower power consumption.

  • Directions 2018: BeiDou builds, diversifies, expands

    Directions 2018: BeiDou builds, diversifies, expands

    By Changfeng Yang,
    Chief Architect of BeiDou Navigation Satellite System

    Changfeng Yang

    As one of the four major GNSS providers, the establishment of BeiDou Navigation Satellite System (BDS) has been steadily developed, following a three-step strategy. By around 2020, BDS will form a nominal space constellation consisting of 30 satellites, including three satellites in geostationary Earth orbit (GEO), three satellites in inclined geosynchronous satellite orbit (IGSO) and 24 satellites in medium Earth orbit (MEO). It will provide global users with open and high-quality services free of charge, including navigation, positioning, timing, short message communication, search and rescue and so on.

    BDS is aimed at developing into a world-class global navigation satellite system, with innovative and advanced technologies, extraordinary user experience, international development and worldwide presence, which can provide fundamental time and space reference for national defense and economic-social development, and advance the progress of high-tech and IT industries.

    BDS has initiated several innovative attempts in the fields of both international satellite navigation and domestic aerospace for the first time, and paved a unique development path of a satellite navigation system, with an eye on the state conditions and distinctive features. On Jan. 9, 2017, the BD-2 Project won the top National Scientific and Technological Progress Award. In 2017, BDS achieved fruitful results in the aspects of system construction, integrated applications and international development.

    System Construction

    Through upgrading and reconstructing the ground system, the service performance, stability and availability of the BD-2 constellation have been improved. To achieve user-oriented services, the updated Interface Control Document (ICD) for B1C and B2a open service signals (Version 2.1) was released in accordance with the constellation change.

    The international GNSS Monitoring and Assessment System (iGMAS) has been built, consisting of eight domestic monitoring stations and 16 overseas stations, to monitor and assess the service performances of BDS, GPS, GLONASS and Galileo at real-time worldwide. It has taken all factors into consideration, including constellation status, signal-in-space, navigation message, service performance and high-precision products, and so on. According to its analysis results, the nominal positioning accuracy of the BD-2 system in the coverage area has been optimized from 10 meters to 8 meters.

    Development of the BD-3 System. On Nov. 5, the first pair of the 24 BD-3 MEO satellites were successfully launched, while another pair is planned to be launched by the end of the year.

    Liftoff of the first pair of the BD-3 MEO satellites on Nov. 5, 2017. (Credit: Xinhua)

    The BD-3 satellites are equipped with B1C and B2a signals with optimized performance, which are compatible and interoperable with other GNSS signals. The interface control document of B1C and B2a signals (beta version) was released in September. The BD-3 satellites also adopt the higher-performance rubidium atomic clock with stability of E-14 and hydrogen atomic clock with stability of E-15. By utilizing new technologies, the signal-in-space (SIS) accuracy will be superior to 0.5 m; the position accuracy will be doubled or quadrupled, and reach 2.5 m to 5 m.

    The BD-3 system will retain the short message communication service of its predecessors, and further enhance basic positioning, navigation and timing (PNT) service capabilities. Satellite-based augmentation system (SBAS) and search-and-rescue (SAR) services will be added and developed according to international standards.

    After in-orbit tests and networking validation, the BD-3 satellites will be able to provide operational services, and accelerate the global coverage of BDS.

    Ground-Based Augmentation. The Phase I construction of the BDS/GNSS ground-based augmentation system has been completed, consisting of 150 framework reference stations, 1,200 reference stations of higher density network, national data processing center, six industrial data-processing centers, and manufacturing of user terminals. This system has achieved basic service capabilities, and its service performance standard (version 1.0) has been released. Through integration with the internet, a cloud platform has been established to provide high-precision space-time information services, including real-time navigation services at meter-level and decimeter-level, as well as precise positioning services at centimeter-level and millimeter-level.

    Satellite-Based Augmentation. Based on the International Civil Aviation Organization (ICAO) standards, system demonstration and validation work on the BeiDou Satellite-Based Augmentation System (BDSBAS) has been completed, and the technical status of the system has been confirmed in accordance of the next-generation SBAS Dual Frequency Multiple Constellation (DFMC) standards.

    Integrated Applications

    Currently, a great number of independent, self-controlled intellectual property rights on the fundamental BDS products have been achieved. World-class, advanced technologies have been developed. With the release of the first Chinese in-house developed meter-level fast positioning BDS chip, BDS applications have begun to embrace the era of meter-level positioning.

    In 2017, the sales volume of BDS navigation chips and modules exceeded 50 million pieces, and that of high-precision surveying boards and navigation antenna captured 30% and 90% of market shares respectively. There are more than 14,000 enterprises (including more than 50 publicly listed companies), and more than 450,000 employees in China engaging in BDS-related business.

    The annual output value of the publicly listed company in 2017 is more than RMB 50 billion (US $7.53 billion). The number of terminals produced by domestic enterprises surpasses 40 million pieces/sets. BDS has gained recognition from mainstream chip producers such as Qualcomm, Trimble, Hemisphere GNSS, Huawei, Samsung, u-blox, MTK, Broadcom, NovAtel and more, and the total number of terminals is estimated to surpass 300 million pieces or sets.

    BDS continues to:

    • promote integrated applications and development of related industries;
    • bring GNSS high-precision services in combination with cloud computing, Internet of Things, big data and other technologies;
    • push forward the integration between BDS-related industries and high-end manufacturing, software, and integrated data industries.

    BDS has been applied in the transportation, logistics, emergency rescue, marine fishing and other fields, which has greatly improved production efficiency, reduced resource consumption, and lowered pollution. For example, benefiting from the BDS applications in traffic management industry, the number of major accidents has decreased by 46.7%, and the death toll has been reduced by 48.9%. With BDS-based maritime applications, more than 10,000 lives have been saved.

    BDS/GNSS augmentation services have been applied to precision agriculture, land mapping, monitoring on deformation and displacement of large-scale public facilities, and earthquake and geological hazard measurement and survey; the latter has provided important monitoring for public safety. As a result, the production of precision agriculture has increased by 5%, and the oil consumption by agricultural machinery has decreased by 10%. The time for surveying and mapping of national land is shortened from a few days to several seconds.

    BDS has been fully put into mass applications. BDS-based navigation services have been adopted by various enterprises, such as Huawei, ZTE, Baidu, Autonavi, Alibaba, JD and others in the fields of manufacturing of mobile and smart terminals, location-based services (LBS), e-commerce, and so on. BDS-based LBS have been widely applied in the mass consumption sector and people’s livelihood, and many innovative applications have emerged, such as caring for seniors and children, shared vehicles, BDS-based logistics, and so on, which have been changing people’s lives and providing more convenience for the public.

    International Development

    At present, BDS has covered more than 50 countries and more than 3 billion people. BDS-related products have gained access to the markets of more than 70 countries and regions, more than 30 of which are along the (land-based) Belt and (maritime) Road (in line with the Belt and Road Initiative). Through joint applications with other compatible navigation satellite systems, BDS provides global users with diversified choices for better application experience.

    Meanwhile, the iGMAS has contributed to the implementation of the Asia-Pacific Space Cooperation Organization project, iGMAS-International GNSS Service Pilot experimental project, and Sino-Russian monitoring and assessment cooperation, and has provided GNSS users with authentic third-party assessment results. China continuously pushes forward BDS to be recognized by the ICAO, International Maritime Organization (IMO), mobile communication standard Partnership Project and other organizations, to serve the world in line with international conventions.

    In October, three PRN codes which are essential to the development of BDSBAS were assigned; the SBAS service provider identifier and UTC standard identifier have been assigned to BDSBAS by ICAO, which marks BDSBAS an official SBAS provider in the ICAO family, and lays the foundation for the follow-up construction of BDSBAS, as well as its provision of standard navigation services for the civil aviation sector.

    In March, a multi-system (including GPS, BDS and GLONASS) ship-borne receiver standard was approved by the IMO. BDS has also been included in the PNT guidelines of maritime applications.

    In the field of mobile communication, 26 technical standards that support the BDS positioning function have been adopted by the third- and fourth-generation mobile communication standard Partnership Projects.

    Future Plans

    BDS will keep improving its continuous stability and service accuracy. Two more BD-2 replacement satellites will be launched in 2018, ensuring its regional service performance will be remain stable and be enhanced.

    Eighteen BD-3 MEO satellites and one BD-3 GEO satellite will be launched by around the end of 2018. Upon the deployment of those 19 satellites, BD-3 will possess the initial operational capability and serve the countries along the Belt and Road. The official version of ICD for B1C and B2a open service signals, as well as other system documents, will be released, in line with the operational status of BD-3 satellites, for the convenience of public applications.

    In regard to augmentation systems, China plans to complete the construction of Phase II BDS/GNSS ground-based augmentation system in 2018, and advance the recognition of BDS-based high-precision services as public goods. In 2018, the first BDSBAS GEO satellite with the BDSBAS payload will be launched to start the deployment of the BDSBAS system.

    In terms of applications and international development, China will give full play to the role of BDS in the integration procedure between industrialization and IT applications, to promote the development of information industry, adjustment and upgrading of industrial structure.

    China will also strengthen the cooperation and communication with other navigation satellite system providers, carry out coordination under the framework of international organizations and multilateral platforms, improve the international development of BDS, provide better services for users along the Belt and Road, and expand BDS services to serve users worldwide.