GPS World

Category: GNSS

  • Horizon broad but troubled for 2018

    It is the best of times, it is the worst of times. GPS modernization, once gasping for breath by the side of the track, is back in the race and pulling ahead. Relentless innovation in user equipment and newly opened software access mean that high-precision positioning may soon be available to owners of mere tablet computers. Spoofing counter-measures are growing in sophistication and availability. GPS continues to drive many sectors of the economy, with a  benefit of as much as $65 billion per day to the U.S.

    Yet there are a few flies in the modernization ointment. And GPS may soon collide, catastrophically, with that other U.S. military invention from the 1970s that also leaped the fence into the civic domain and life-changed billions of people around the world: the Internet.

    Note: After this issue, we are temporarily suspending publication of the GNSS Design & Test e-newsletter. Subscribers who do not already receive the Navigate! Weekly e-newsletter will in 2018 find it in their inbox each Tuesday.  Navigate! covers a broad range of GNSS and PNT industry news and all GNSS constellation and signal updates.  You may freely unsubscribe if you wish.  The final Navigate! newsletter of each month will carry my GNSS Design & Test column — so, I’m not going away!
    — AC

    Let’s open these boxes one by one.

    Modernization. The first satellite GPS III satellite, declared available for launch in September, appears headed for a March 2018 lift-off. Both the GPS III digital navigation payload and the ground-control software programs are recovering momentum following earlier hiccups and delays. The first III satellite has successfully “talked” with the OCX system on the ground. Lockheed Marting is building 10 of the satellites for the Air Force. Harris Corporation delivered the fourth of 10 digital payloads to Lockheed, and said it would ship four more in 2018. Raytheon is the prime contractor for OCX.

    The Government Accountability Office (GAO) projected that the current constellation of 31 GPS II satellites will remain operational until 2021, two years longer than previously estimated. This affords some breathing room for the seven GPS III satellites scheduled to be in orbit by then to start replacing the long-lived II generation. No longer need we fear the constellation gap, an alarm sounded by the same GAO back in 2009.

    Problems Ahead. But this year’s GAO report also warns that GPS III’s increasing program complexity and upgrades required for new encrypted signals mean that it will take longer for ground infrastructure and user equipment to catch up in capability afforded by the new satellites.

    Five programs are now encompassed under the rubric of GPS modernization: the satellites, next-generation ground control (OCX), military user equipment, contingency operations and military code (M-code) early use.

    Just because the satellite schedule has regained its footing and is racing forward does not mean that M-code software and installing the receivers needed to acquire it aboard major U.S. weapon systems are keeping up pace with the pack. “Additional development is necessary to make M-code work with over 700 weapon systems that require it,” according to GAO analyst Christina Chaplain. Long message short: the new satellite constellation may be orbiting in the skies years before user equipment and software are in place. “War fighters will have to operate with a mix of older and newer receiver cards.”

    Consumer Access to Precision. The January cover story in GPS World magazine will show the results of very promising new tests taking advantage of access to raw GNSS observables now possible thanks to Android. “For those who want high accuracy, but don’t need it full time, high-productivity dedicated professional solutions may not be cost-justified,” writes Stuart Riley along with his co-authors, all from Trimble. “In these cases, a positioning-as-a-service subscription could offer a viable use model. Achieving precision positioning with just a standard mobile device, a correction stream using the mobile device’s data connection and a high-accuracy positioning application produces a very low barrier to achieving high accuracy.”

    One of the figures from “Positioning with Android.” Code RTX performance the dataset sampled Nov 20 and corresponding RTK and RTX phase solutions — cell-phone GNSS antenna.

    “While we expect that dedicated system approaches employing a custom GNSS chipset and firmware and purpose-built precision applications will continue to be the right solution for industry professionals,” they continue, “it is clear that the ubiquity of consumer mobiles, with increasing compute power, ruggedness and an expanding feature set represents a fertile ground for new development of improved positioning systems that don’t have strict professional requirements.

    “A range of new use models and applications will be enabled by consumer mobile phones with technology that improves positioning performance. The goal of the work presented here is to assess what level of performance can be achieved by using proprietary PVT (Position Velocity Time) engine(s) utilizing GNSS measurements from the Android GNSS measurement API.”

    Look for the January issue in your mailbox by mid-next month.

    Spoofing. This has been the hottest issue, by far, during the past year — maybe two — at technical conferences around the world. Its role has been speculated in some rather notorious seafaring accidents. Its potential to wreck many carefully wrought schemes of transport, finance, safety, security, defense, power supply and more has been resoundingly aired. But help is on the way. Javad Ashjaee in the January magazine’s Expert Opinion column lays out an anti-spoofing strategy that has been installed, as an option, in all OEM boards offered by JAVAD GNSS.

    In its most basic form, it amounts to “it is vital that in areas that spoofing danger exists, users employ OEM boards that provide more satellite systems and more signals, rather than using a simple GPS C/A code, for example.”

    Heartbreak Dead Ahead. Finally, the January issue contains a lengthy treatise by Brad Parkinson, variously the grandfather, godfather, or just plain father of GPS, on a burgeoning danger that threatens the whole system and the vast economic benefit it provides.

    Widespread big data streaming, storage in the cloud, and the much-ballyhooed Internet-of-Things are accelerating the World Wide Web’s breakneck consumption of broadband. More, more, more is needed, and more again tomorrow. We are all complicit, to use a current term, in this.

    Macro urban transmitter, high-precision receiver. 1530 MHz

    Every single sliver of radio-frequency band is now worth billions. And this is neither an infinite nor a renewable resource. There’s only so much. No one’s talking about taking away the small radionav portion of the spectrum (yet), but serious, well-funded and well-friended efforts seek to park massive transmitters right next door to it and effectively obliterate the signal, not only of GPS but other GNSS as well.

    LightSquared tried this once, in 2010-11, and failed. Now the company is back under a new name, and in the current political climate it has more than a fighting chance of knocking the RF legs out from under the PNT community and all who depend upon it. Which, again, is all of us.

    Talk about conflicting priorities.

    “I believe the concept of allowing the installation of transmitting towers that, by design, will interfere with normal GPS use at some distance away, opens the door to tacit approval of short-range (or not-so-short-range) GPS jammers,” writes Parkinson.

    Well, let’s put all that trouble aside, just for a few more weeks. Enjoy, everyone out there, your winter holidays if you are lucky enough to have some, and we’ll return to business in January.

    Warmest wishes,

    Alan Cameron|
    GPS World and Geospatial Solutions

     

  • PNT Roundup: Measuring range of motion, new app offers urban guiding

    PNT Roundup: Measuring range of motion, new app offers urban guiding

    Measuring recovering patients’ range of motion

    Positioning on a micro-scale is the task of a new sensor that reports on range of motion (ROM) achieved in stretching exercises and other post-operative activities by at-home patients after discharge from hospital. Telit, a company active in sensors for the Internet of Things (IoT), announced that U.K.-based 270 Vision Limited has selected Telit’s BlueMod+SR Bluetooth module for its BPMpro Mark 2 sensor for remote, precision measurement of patient ROM.

    The BPS (Body Performance Measurement) wearable sensor is a medical device that measures patient ROM before and during rehabilitation. Post-surgery, patients are discharged to be remotely monitored at home as they undertake their daily routine using a BPMpro sensor. The captured sensor output displays on a patient tablet running BPMpathway software and streams live to the clinician, who can use this data to assess the patient’s progress. With the patient recovery data collected by BPMpathway, clinicians can tailor an orthopedic patient’s post-operative support to meet their individual needs, without having to wait for a face-to-face consultation.

    The BlueMod+SR module is a very small form factor dual-mode Bluetooth 4.0 module (17 x 10 x 2.6 mm). Range in line of sight is about 100 meters. Dual mode means it supports classic Bluetooth basic rate (BR) and enhanced data rate (EDR) operations as well as Bluetooth low energy (LE).

    New app promises better-than-GPS urban guiding

    Attention, GPS World readers living in or visiting Central London, Mountain View, California or San Francisco. Public beta of a new app ­(iOS only) will take you by the hand — er, phone — and lead you around the fair city; those cities only, at present. More intriguing, it claims to deliver “better than GPS accuracy.”

    This augmented reality (AR) navigation employs an AR-native framework, Apple’s ARKit. Blippar touts its AR City app for something it calls “urban visual positioning…which localizes users with higher accuracy than GPS, thanks to computer vision.” The app uses visual inertial odometry, interpreting movement seen through the camera, to minimize position errors, that is, in a sense, to correct GPS.

    Holding the phone in front of one’s face in tourist fashion, the user receives nearby points of interest based on what he or she can actually see. The app feature three layers of information:

    AR Basic Navigation. A visualization of walking routes through augmented reality.

    Enhanced Map Content. Overlays of information and content related to user location in AR — for example, streets and points of interest.

    Urban Visual Positioning. Recognition, positioning and directional information via computer vision.

    AR basic navigation, available everywhere that is supported by Apple Maps, visualizes routes with arrows shown in augmented reality. AR basic navigation uses GPS to estimate the absolute position of the user, and visual inertial odometry (VIO) to track their local movement. Blippar integrates GPS and VIO by building on the ARCL library, which uses Apple’s ARKit for VIO and Core Location for GPS.

    GPS alone doesn’t give a high enough level of accuracy when looking at the map and has an average error rate of 16 m in cities, according to Blippar, which claims its urban visual positioning provides more than twice its accuracy.

  • Search engine offers range of opportunities using satellite imagery

    Where are baseball stadiums in the world?

    Where are all the windmills on Earth? Or oil derricks? How about baseball stadiums?

    You could scan through the millions of satellite images snapped by hundreds of satellites now circling the planet. Or you could try Descartes Labs’ demo search engine.

    Satellites are snapping images of the Earth every day. Alongside Planet Inc. and DigitalGlobe satellites, imaging constellations are planned from companies such as Urthecast and Astro Digital (the latter launched its first pair of satellites in July). But how do we make use of all of that data in an organized, searchable way?

    New Mexico startup Descartes Labs has created a cloud-based supercomputing platform to apply machine intelligence to massive data sets, using satellite imagery to model complex systems on the planet.

    While Descartes started by focusing on forestry and agriculture, its new Geovisual Search tool allows users to find similar-looking objects of any kind all over the globe. Just click anywhere on the map and a red tile appears, enabling users to search for similar objects. Descartes was inspired by a team at Carnegie Mellon University, who applied the principles of visual search to seven cities around the world in a demo called Terrapattern. Descartes has built three demo maps on three different scales: The continental United States, China and the entire world.

    Check out GeoVisual Search at https://search.descarteslabs.com, and Terrapattern at www.terrapattern.com.

  • First GPS III satellite receives commands from OCX

    First GPS III satellite receives commands from OCX

    The first advanced GPS III satellite successfully established remote connectivity and communicated with the next-generation Operational Control System (OCX), further validating the U.S. Air Force’s modernized GPS is ready to launch its first satellite.

    On Nov. 2, GPS III Space Vehicle 01 (GPS III SV01), the first of 10 GPS III satellites designed by Lockheed Martin, and OCX, being developed by Raytheon Corporation, successfully completed Factory Mission Readiness Testing (FMRT).

    The FMRT validated the command and control interaction between GPS III and the OCX’s Launch and Checkout System (LCS) through a simulated full launch and early orbit mission event sequence.

    During this end-to-end system demonstration, command signals were sent from the latest OCX LCS software installed at Lockheed Martin’s Launch and Check Out Capability node in Denver to Schriever Air Force Base in Colorado Springs, Colorado.

    From there, the commands were uplinked back to the GPS III SV01 satellite, currently awaiting a call up for launch at Lockheed Martin.

    “During FMRT, GPS III SV01 received and successfully processed OCX commands that are routinely sent during launch, transfer orbit maneuvers, deployments and payload initialization,” said Mark Stewart, Lockheed Martin’s vice president for Navigation Systems. “We thoroughly tested the first GPS III satellite just like we are going to fly it in 2018.”

    GPS III SV01 and OCX first “talked” to each other during a link check on October 3, 2017.

    “This was the first time the launch and checkout system directly interfaced with the GPS III satellite,” said Bill Sullivan, vice president of Raytheon’s GPS OCX program. “We’re making consistent, steady progress, and that’s driving us toward a successful launch next year.”

    The demo further verifies the space-to-ground compatibility between GPS III satellites and OCX. During a 2013 Compatibility & Integration test, Lockheed Martin’s GPS III Nonflight Satellite Testbed (GNST) — a full-sized, functional satellite prototype — also connected with and received commands from an earlier version of Raytheon’s OCX LCS software.

    On Sept. 22, the Air Force declared GPS III SV01 “available for launch,” with launch expected in 2018. The successful FMRT was the final validation that GPS III SV01 is ready to be shipped to the launch pad.

    GPS III will have three times better accuracy and up to eight times improved anti-jamming capabilities. Spacecraft life will extend to 15 years, 25 percent longer than the newest GPS satellites on-orbit today. GPS III’s new L1C civil signal also will make it the first GPS satellite to be interoperable with other international global navigation satellite systems, like Galileo.

    OCX will revolutionize GPS command and control and mission management capabilities. It will control all legacy and new signals, provide protection against evolving cyber threats, and reduce operation and sustainment costs through efficient software architecture, automation and performance-based logistics. OCX represents a quantum leap in capabilities over the current system, providing flexibility and adaptability to meet future GPS mission needs.

    The GPS III and OCX teams are led by the Global Positioning Systems Directorate at the U.S. Air Force Space and Missile Systems Center. Air Force Space Command’s 2nd Space Operations Squadron (2SOPS), based at Schriever Air Force Base, Colorado, manages and operates the GPS constellation for both civil and military users.

  • Four more Galileo satellites launched into orbit

    Four more Galileo satellites launched into orbit

    Updated with additional details and reaction.

    Liftoff of Ariane 5 Flight VA240 from Europe’s Spaceport in Kourou took place at 18:36 UTC on Dec. 12, 2017, carrying Galileo satellites 19–22. (Photo: ESA)

    On Dec. 12, four more Galileo satellites headed into space to join the navigation constellation. Galileos 19–22 lifted off aboard an Ariane 5 rocket from Europe’s Spaceport in Kourou, French Guiana, at 18:36 UTC (19:36 CET, 15:36 local time).

    After today’s successful launch, only one more launch remains before the Galileo constellation is complete and delivering global coverage.

    Separation of the upper stage occurred about nine minutes after liftoff, followed by the first firing of the upper stage.

    The first pair of 715-kg satellites was released almost 3 hours 36 minutes after liftoff, while the second pair separated 20 minutes later.

    They were released into their target 22,922 km-altitude orbit by the dispenser atop the Ariane 5 upper stage. In the coming days, this quartet will be steered into their final working orbits. There, they will begin around six months of tests — performed by the European Global Navigation Satellite System Agency (GSA) — to check they are ready to join the working Galileo constellation.

    This mission brings the Galileo system to 22 satellites. Initial Services began almost a year ago, on Dec. 15, 2016.

    “Today’s launch is another great achievement, taking us within one step of completing the constellation,” remarked Jan Wörner, ESA’s director general.

    “It is a great achievement of our industrial partners OHB (DE) and SSTL (GB) for the satellites, as well as Thales-Alenia-Space (FR, IT) and Airbus Defense and Space (GB, FR) for the ground segment and all their subcontractors throughout Europe, that Europe now has a formidable global satellite navigation system with remarkable performance.”

    Paul Verhoef, ESA’s director of navigation, added, “ESA is the design agent, system engineer and procurement agent of Galileo on behalf of the European Commission. Galileo is now an operating reality, so, in July, operational oversight of the system was passed to the GSA.

    “Accordingly, GSA took control of these satellites as soon as they separated from their launcher, with ESA maintaining an advisory role. This productive partnership will continue with the next Galileo launch, by Ariane 5 in mid-2018.

    “Meanwhile, ESA is also working with the European Commission and GSA on dedicated research and development efforts and system design to begin the procurement of the Galileo Second Generation, along with other future navigation technologies.”

    Next year’s launch of another quartet will bring the 24‑satellite Galileo constellation to the point of completion, plus two orbital spares.

    Keep up to date here.

  • GSA in Prague brings benefits to Czech Republic

    The Galileo headquarters in Prague.

    The European GNSS Agency (GSA) in Prague, Czech Republic, has brought financial benefits to the country over the past five years — 1 billion crowns, according to a report by Czech Radio. The GSA is the only European-wide government agency sited in the country.

    The GSA moved from Brussels, Belgium, to Prague in 2012.

    The Prague agency – employing around 200 – deals with the programs that will turn the satellite network and signals into applications can be used by companies and the public at large.

    One of the main benefits for the Czech Republic of having the headquarters in Prague is that the country is now on the doorstep for many Czech companies. The number of Czech firms are now receiving research and development funds linked to navigation services has increased ten-fold, with 44 Czech companies directly active in the navigation sector.

    Read more at the Czech Radio site.

  • Galileo satellites atop rocket for Dec. 12 flight

    News from the European Space Agency

    Europe’s next four Galileo navigation satellites are in place atop the Ariane 5, ready to be launched Dec. 12.

    Liftoff from Europe’s Spaceport in Kourou, French Guiana is scheduled for 18:36 GMT (19:36 CET, 15:36 local time), carrying Galileo satellites 19–22.

    Four Galileo satellites seen before being encapsulated by the protective payload fairing on Dec. 7, completing the Ariane 5 for flight VA240, scheduled for Dec. 12.

    Completion of Galileo’s Ariane 5 rocket took place in the Spaceport’s Final Assembly Building, following the arrival there of the quartet of satellites, already attached to the dispenser that will hold them in position during launch, then release them into their target 22 922 km-altitude orbit

    Next, the satellites plus dispenser were placed atop the Ariane 5’s upper stage, after which the 14 m-long protective fairing was lowered over the Galileos — the last time they will be seen by human eyes. This fairing will protect them from the onrushing atmosphere during ascent.

    The next step will be Monday’s rollout to the launch zone.

    This mission will bring the Galileo system to 22 satellites. Initial Services began almost a year ago, on Dec. 15, 2016.

    Next year’s launch of another quartet will bring the constellation of 24 satellites to completion, plus two orbital spares.

    Galileo is Europe’s civil global satellite navigation system. It will allow users worldwide to know their exact position in time and space with great precision and reliability.

  • 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.

  • Directions 2018: Galileo ascendant

    Directions 2018: Galileo ascendant

    By Paul Verhoef
    Director of the Galileo Programme and Navigation-related Activities,
    European Space Agency

    Paul Verhoef, director of the Galileo Programme addresses the audience at ESA's annual Navigation Days, held Jan. 26. (Photo: ESA)
    Paul Verhoef, director of the Galileo Programme. (Photo: ESA)

    The European Space Agency (ESA) and the European GNSS Agency (GSA) are starting 2018 with the commissioning and In-Orbit Testing (IOT) of four new Galileo satellites.

    This work is fairly routine for us as we have achieved the process successfully many times. But the impact of four new satellites for Galileo services is a different story.

    This batch of satellites provided by OHB of Germany — 19, 20, 21 and 22  — will bring our constellation to 22 satellites. Together with the necessary ground segment delivered by Thales Alenia Space (TAS) and Airbus Defense and Space (ADS) and their many subcontractors throughout Europe, this will be providing availability to users anywhere in the world in order to achieve a high-quality position solution 99.8% of the time. “High quality” is hereby meant that the position dilution of precision (PDOP) will be smaller than 5, with our final accuracy for a full 24 FOC satellites operating at full potential being PDOP ~ 2.4.

    This achievement will create a step change in the ability of service providers and equipment manufacturers to utilize the Galileo service. For all intents and purposes, it means the Galileo signal can always be relied upon to be there, and industry can sell products and design the power budget of devices based upon that fact.

    Dual Frequency. The first mass-market GNSS receiver chip for smartphones and mobile devices that is able to utilize dual-frequency Galileo signals was released by Broadcom in September, able to employ both L1/E1 and L5/E5 signals. In 2018, dual-frequency technology like this will provide an order of magnitude increase in the performance of mobile device location-based services (LBS), especially in urban environments, and Broadcom advertises a 50% reduction in power consumption. The world of mobile-device LBS is going to change in 2018, and it will be due to the availability of Galileo.

    It will not be the first time the partnership of ESA, the European Commission (EC) and the GSA has made a service available that has changed the nature of the marketplace. The GSA already has in service the ESA-designed EGNOS LPV200 aircraft approach service performing so well that countries like France have taken the decision to phase out the terrestrial Instrument Landing System that has burdened the capital expenditure budgets of airports in the past.

    We have had discussions with several commercial organizations that are interested in building products around Galileo, and I am excited to see what they are going to come up with. With Galileo Initial Services the world had a new navigation signal to study and trial. In 2018 the world will have a new star to navigate by — well, a new constellation of 22 to 24 stars, I should say!

    FOC. In the summer of 2018 we will launch the final part of the Galileo FOC constellation (geometrically speaking) with four more satellites taking us beyond the 24 needed for 100% coverage and minimum performance limitation from satellite geometry. The launch will also provide our first in-orbit spares, enabling us to plan for the end of life of our old validation phase satellites or otherwise supplement the constellation to improve performance.

    What might we do with these in-orbit spares? Our first priority is to complete a constellation of 24 satellites in the correct orbits for minimum PDOP; as you know, a Fregat upper-stage malfunction left GSAT 0201 and 0202 in orbits too elliptical to correct fully, so the current plan is to complete the 24-satellite geometry. 0201 and 0202 are foreseen to be fully integrated in the Galileo operational system in 2018 following further testing and preparations, allowing us to have a 24+2 constellation with “hot back-up” from 0201 and 0202 contributing at around current GPS satellite levels of accuracy.

    “It will not be the first — nor the last — time the partnership of ESA, the EC and the GSA has made a service available that has changed the nature of the marketplace.”

    Of course, as is known to the community, the validation-phase satellite GSAT 0104 is down to single frequency, and we routinely monitor the health of all satellites. 0104 is the only satellite that has lost part of its function; designed-in redundancy has managed all other problems.

    However, obviously we will be examining all options for deployment to ensure that the Galileo schedule is not impacted by in-orbit failures, and those we have experienced we have learned from and mitigated successfully without impacting the service.

    The first two spares are not the end of our ability to maintain the constellation and our system performance. All four validation phase satellites will need to be replaced, and so the “Batch 3” satellite procurement will continue to regularly roll out satellites for replenishment of the constellation.

    Enhancements. That won’t mean we will be resting on our laurels. In 2018 we also plan to release enhancements to the ground segment for Galileo, a process that will be a first as the system is already being operated by the GSA.

    The process of managing an in-service upgrade program with the GSA is going to be new and challenging, but we have a strong engineering support team deployed as part of our working arrangement with the GSA to help ensure the process goes smoothly.

    Of course, the need for GSA to be able to continue smooth operations imposes extra discipline and imposes on us a balance between stable operations and continued build-out of the infrastructure. We do not consider this to be a problem; on the contrary, the focus will be on robust operations and availability to the user.

    Back at base (ESTEC in the Netherlands for Galileo and Toulouse, France, for EGNOS) we are full steam ahead on preparing the future. We are moving forward at considerable pace with our next-generation designs that develop new functionality for continuous service improvements.

    Free PPP. Galileo was designed to broadcast a Commercial Service signal providing services such as precise point positioning to paying customers, but we are pleased to able to report that the EC has confirmed that this service will be provided for free by the European Union. In 2018/2019 the GSA will select the providers and get that unique, free service on the air.

    In 2017 the EC confirmed the decision to implement the commercial service using E6-B with both encrypted and open components so all users could benefit for all frequency bands. Now, with the decision to make the service available free of charge, all users of Galileo, with the right type of receiver, will be able to achieve position fixes with an accuracy around 10 cm from Galileo’s first-generation constellation by 2020/2021.

    The Galileo Public Regulated Service will also be a focus, with the EC soon to decide upon release dates for the first milestones on the service roadmap. The infrastructure and equipment to support a secure service is being put in place, and I can’t say more for security!

    The next generation of European GNSS technology will include multi-constellation EGNOS, Galileo 2nd Generation (G2G) and a transition batch of satellites between the first and second generations to get the best technology proven in flight and working for Galileo users as soon as possible. G2G will reach its System Requirements Review stage in the first half of 2019. To be ready for that we are looking at:

    • clock technology and ensembles
    • inter satellite links
    • propulsion technology
    • flexible payloads and power allocation
    • 5G telecoms networks standards and what we need to do ensure we provide the timing services those networks will need and new signals with time to first fix (TTFF) and power requirements for acquisition of signal that are compatible with 5G devices. Look out for a new pilot signal E1-D to move forward on this.
    • Open Service authentication and support for ARAIM (Advanced Receiver Autonomous Integrity Monitoring).

    Finally, 2018 will see the first contract awards of the Navigation Innovation Support Programme. This is a programme specifically designed to encourage R&D, new concepts and new products and to ensure that 2018 is not the last time ESA with the EC and its industrial partners deploy a GNSS service for GSA to operate that changes the world.

  • Directions 2018: GLONASS focuses on user needs

    By Sergey Karutin, GLONASS designer general;
    Nicolay Testoedov, Director General, SC Information Satellite Systems;
    and Andrey Tulin, Director General, SC Russian Space Systems

    This year has marked the 35th anniversary of the first GLONASS launch. During these years, the world has made great strides through high tech, and now no modern society can progress without satellite-based navigation.

    Today’s urban resident can hardly do without a smartphone planning his route through traffic, determining the paid parking site location or getting a reminder of parking session completion once he has left the parking lot.

    The search for the nearest pharmacy, gas station, restaurant or any other point of interest is of vital necessity today. The growing dependence of modern society on navigation signals-in-space increases the responsibilities of GNSS providers. At the same time, users long for simplicity in getting quality services. That is why this year the GLONASS team is going to set up its most ambitious program: improving the quality of the GLONASS services at a user level.

    The traditional GLONASS conception of signal-in-space accuracy is now being augmented by the user level performance estimation. Due to the fact that the signal propagation environment contributes a lot to the positioning error budget, it is obvious that users need information that would reduce the influence of signal propagation path on the positioning accuracy.

    Glonass-M satellites currently form the core of the GLONASS constellation, and with six ground spares now in stock, they will continue to do so for at least the next eight years. Therefore, in 2018 the new edition of L1 and L2 FDMA Interface Control Documents are to be published which will include the ionospheric and tropospheric models recommended in the recently released GLONASS CDMA Signals ICDs.

    Glonass-K2 satellite (artist’s rendering).

    We plan to use the spare bits within the navigation superframe of FDMA signals to transmit ionospheric parameters described in the General Description of the GLObal NAvigation Satellite System with the Code Division Multiple Access Signals ICD.

    Studies being performed demonstrate up to 70 percent reduction in impact of ionospheric refraction when using the adaptive model transmitted by the three parameters: the numerical factor for the peak TEC (Total Electron Content) of F2 ionosphere layer, the solar activity index and the daily geomagnetic activity index. In the new CDMA signal message, these parameters are initially provided.

    To enable the unanimity of technologies for reducing the hydrostatic component of the tropospheric delay, which accounts for 80 percent of its value, the both FDMA and CDMA Signals ICDs will include the latitudinal tropospheric model based on the preliminary set tabular values.

    The preliminary design review for the technical baseline of the fourth-generation Glonass-K2 satellite has been passed this year. The new cubic arrangement of the platform enables mitigation of unmodeled forces and transition of propellant tank to the satellite’s center of mass.

    This provides for the relative position constancy for the satellite’s center of mass and the satellite’s antenna phase center during the satellite’s lifetime. This platform arrangement also accommodates the whole ensemble of navigation signals (both CDMA and FDMA) on the single phased-array antenna system.

    Glonass-K2 is equipped with the new atomic frequency standard composed of the legacy quantum frequency standard based on the cesium beam tube and the passive hydrogen maser. The miniature PHM with the relative daily stability of 5×10-15 will be installed onboard the satellite to be launched in 2020.

    Introduction of the new satellite will enable a new constellation sustainment strategy — through the both dual launches by Angara-A5 launcher from Vostochny and single launches by Soyuz from Plesetsk — to provide on-demand replenishment of the constellation.

    By 2020, when we celebrate the 25th anniversary of GLONASS full operational capability, all the efforts mentioned above will offer new quality of services to GLONASS users prioritized as per their needs.

  • New M-code GPS capability tested onboard B-2 bomber

    New M-code GPS capability tested onboard B-2 bomber

    M-code receiver enhances security, positioning, navigation and timing capabilities

    The U.S. Air Force recently completed a series of successful flight tests of its next-generation military-code GPS using a Raytheon Company receiver onboard a B-2 Spirit at Edwards Air Force Base, California.

    This first M-code test onboard the B-2 is an important milestone for the U.S. government-led GPS modernization effort to enhance security, positioning, navigation and timing capabilities for U.S. military and civilian applications.

    Military GPS user equipment (MGUE) M-code receivers will give military aircraft, ships and ground vehicles access to the modernized GPS network.

    “M-code receivers unlock the next-generation GPS network for military users,” said Rick Yuse, president of Raytheon Space and Airborne Systems. “This test demonstrated M-code capability onboard the B-2 for the first time, marking an early milestone for the overall GPS modernization effort.”

    The tests verified the integration of an MGUE-equipped risk reduction prototype of Raytheon’s miniaturized GPS airborne MAGR-2K-M receiver with B-2 systems in representative flight and mission profiles.

    Raytheon is developing M-code receivers under a contract with the USAF Global Positioning System Directorate GPS User Equipment Division. The company is also under contract with the USAF Joint Service Systems Management Office to qualify and certify the MAGR-2K-M and deliver production representative units to support platform integration and testing.

  • Android software release expands GNSS analysis tool capabilities

    Google has publicly released GNSS Analysis app v2.5.0.0 with advanced processing and analysis tools for raw GNSS measurements retrieved from Android devices. The primary intent of these tools is to enable device manufacturers to see in detail how well the GNSS receivers are working in each particular device design, and thus improve the design and GNSS performance in their devices. However, with the tools publicly available, there is also significant value to the research and app developer community.

    The v2.5 release builds further on capabilities first announced and made available in 2016 in Android Nougat, when the application programming interfaces (APIs) were introduced, and then updated in May 2017.  The latest iteration, announced December 1, now includes the following updates:

    • Smoothed pseudoranges.
    • Plots of positions from raw and smoothed pseudorange.
    • Plots of measurement errors for raw and smoothed pseudorange.
    • Saves raw and smoothed pseudoranges to derived data file.
    • Calculates and saves intersystem time biases to derived data file.

    Full details, download links, user manual, and more are available at an Android developers’ blog post: GNSS Analysis Tools. The article also lists Android devices that support raw GNSS measurements. Android powers more than 2 billion devices, and Android phones are made by many different manufacturers.

    In its basic and original form, the GNSS Analysis Tool is a desktop application that takes in raw the GNSS Measurements logged from the user’s Android device as input. The desktop application provides interactive plots, organized into three columns showing the behavior of the RF, clock, and measurements. The user can see the behavior of the GNSS receiver in great detail, including receiver clock offset and drift to the order of 1 nanosecond and 1 ppb and measurement errors on a satellite-by-satellite basis. This enables sophisticated analysis at a level that was previously almost inaccessible to anyone but the chip manufacturers themselves.

    The tools support multi-constellation (GPS, GLONASS, Galileo, BeiDou and QZSS) and multi-frequency. The image below shows the satellite locations for L1, L5, E1 and E5 signals tracked by a dual-frequency chip.

    The tools provide an interactive control screen for manipulating the plots. The tools also provide automatic test reports of receivers, evaluating the API implementation, received signal, clock behavior, and measurement accuracy. In each case it will report PASS or FAIL based on the performance against known good benchmarks. This test report is primarily meant for the device manufacturers to use as they iterate on the design and implementation of a new device.

    Frank van Diggelen, Android Location Lead at Google, gave a recent workshop presentation at the Royal Institute of Navigation’s International Navigation Conference (RIN INC) in Brighton, UK. Reportedly the topic  of most interest to the conference audience was carrier phase from phones, which is available through the Accumulated Delta Range (ADR) field in the raw measurements. The table at the GNSS Tools page shows which phones support ADR. Apps are appearing on the apps store to take advantage of the raw measurements, and give enhanced accuracy through PPP  and RTK.

    In particular, the Centre National d’Etudes Spatiales (CNES), the French space agency, has released two apps built on GNSS Raw Measurements: PPP WizLite, and RTCM Converter.  The German company Geo++ Gmbh has a RINEX Logger.

    Frank van Diggelen conducts Android location workshop at RININC.

    The RIN INC workshop/demo showed how data collected earlier in the day on Brighton’s sea front could then be analyzed using the new release. Van Diggelen gave an example of how combined ionosphere and troposphere delays could be calculated using the GNSS Analysis tools release based on the raw data logged that day. A reference satellite was chosen and the tools enabled relative delays between that satellite, which was near zenith, and all other satellites in the constellation to be measured. Understanding this has real potential in improving the accuracy of single-frequency GNSS devices. The potential applications include jammer detection via AGC analysis, carrier-phase analysis and many others.