Geneq Inc. announced it will be introducing two major product lines on Wednesday, June 10th at the 2013 Esri International User Conference in San Diego, CA.
According to the announcement, Geneq invites interested parties to attend the announcement at a lunch event on Wednesday, July 10th, 12:00p-12:50p, in Room 30C at the San Diego Convention Center. Lunch boxes and drinks will be provided and priority will be given to those who RSVP via email to Marcel Belanger [email protected].
The SXPad product line will be expanded with products that will set a new price/performance standard for sub-meter and centimeter accurate GNSS handheld devices.
The SXBlue product line will be expanded to include an interface to the Apple Ipad, for both sub-meter and centimeter accuracy.
Geneq reports that both announcements promise to introduce ground-breaking products that will set new standards for GNSS mapping and surveying receivers.
Laser Technology, Inc. (LTI) announced it will be unveiling two new TruPulse models July 9, 2013, at the Esri User Conference in San Diego, CA.
Currently in pre-production, LTI reports the new lasers will expand LTI’s TruPulse laser series that are already being used by tens of thousands of professionals worldwide. Listening to key market feedback, LTI has responded by addressing the need for both a lower cost professional measurement laser rangefinder and one that produces a higher level of accuracy.
Be among the first to see the newest additions to the TruPulse laser rangefinder family by visiting LTI’s Esri UC booth number 2517. Another new product to be showcased will be an LTI exclusive FotoMapr L100 GPS unit that integrates with the TruPulse and stores remote offset data. This is low-cost alternative to other GPS handheld devices.
LTI will also be demonstrating other mobile mapping solutions that delivers efficiency to field work, such as LaserGIS for ArcPad, ArcGIS for Mobile, a new LaserSoft Measure app for the iPhone and MapSmart that is packaged with a new lower-cost BAP data collector.
Esri UC attendees can learn how to map with smartphones, tablets and lasers by attending a lunch and learn session Wednesday, July 10 from 12:00– 1:00 p.m., in Room 28C. LTI will be co-hosting the session with GeoSpatial Experts, the leader in photo mapping software.
The presentation will walk through the entire process of capturing geo-tagged photos, remotely positioning your target and measuring additional height data using GeoJot+ and a TruPulse laser.
The field data can then be synced to the cloud and GeoJot+ Core can process everything in the office to create ArcGIS and Google Earth compatible files.
Professionals in forestry, natural resource management, public works, utilities, mining, telecommunication or any other discipline that collects and reports GIS data, will walk away from the Esri UC with knowledge about the most advanced laser measurement and mapping tools available.
More than 30 specialists overseeing the world’s five satellite navigation augmentation systems gathered in Russia last week, planning for a high-performance future with many more navigation satellites in orbit, reports the European Space Agency.
The Satellite-Based Augmentation Systems (SBAS) Interoperability Working Group was hosted June 25–27 in St. Petersburg by Russia’s Roscosmos space agency and the Russian Academy of Sciences.
With augmentation, additional ground monitoring stations and satellite transponders are applied to sharpen satnav accuracy and reliability across given geographical regions. This enhancement makes satnav suitable for the guidance of aircraft and other precision applications.
Today there are three certified SBAS in operation worldwide: the U.S. Wide Area Augmentation System (WAAS), Japan’s Multi-functional Satellite Augmentation System (MSAS), and Europe’s Geostationary Navigation Overlay Service (EGNOS), the last designed by ESA then turned over for operation by the European Satellite Service Provider, ESSP.
Participants of the 25th Satellite-Based Augmentation Systems (SBAS) Interoperability Working Group, taking place on 25–27 June in St Petersburg, Russia, photographed beside Russia’s Svetloe Radio Astronomy Observatory. Equipped with a 32 m-diameter antenna, this site is part of the Very Long Baseline Interferometry network for high-resolution radio astronomy. It is also hosting a reference station for the System of Differential Correction and Monitoring, Russia’s forthcoming SBAS network.
Two more are under development in Russia and India: the Roscosmos-designed System of Differential Correction and Monitoring (SDCM), and the GPS and Geo-Augmented Navigation (GAGAN) system, the work of Indian Civil Aviation and India’s ISRO space agency.
Meeting twice yearly, the task of the Working Group is to ensure that the various systems work together on a standardized
basis, so end-users can pass seamlessly between them.
“The Group’s terms of reference include developing a shared vision for future generations of these systems,” commented Didier Flament, representing ESA.
“The future will see many more navigation satellites in place. So among the most important achievements of the meeting was agreeing on a common SBAS message based on dual-frequency multi-constellation (DFMC) signals from up to four constellations — GPS, Galileo, Compass, and GLONASS — for the post-2020 era.
“Field tests by our Japanese colleagues using GPS and GLONASS combined with MSAS are confirming the improved performance expected from this DFMC concept,” Flament said. “Two solutions have been studied in parallel, one by ESA and one by the U.S. Federal Aviation Authority (FAA). Both have been compared, with a final single definition to be made before the end of this year. This represents a major step forward towards providing a quasi-global SBAS service.”
Comparing current worldwide SBAS coverage – based on WAAS, EGNOS and MSAS – to the situation envisaged for 2020–25: near-global coverage based on WAAS, EGNOS, MAAS, SDCM and GAGAN, with an expanded network of stations in the southern hemisphere, all based on a common dual-frequency/dual satnav standard being finalised by the SBAS Interoperability Working Group.
A Russian Proton-M rocket carrying three GLONASS navigation satellites crashed soon after liftoff today from Kazakhstan’s Baikonur cosmodrome, reports rt.com (Russia Today).
About 10 seconds after takeoff at 02:38 UTC, the rocket swerved, began to correct, but then veered in the opposite direction. It then flew horizontally and started to come apart with its engines in full thrust. Making an arc in the air, the rocket plummeted to Earth and exploded on impact close to another launch pad used for Proton commercial launches.
The crash was broadcast live across Russia. Fears of a possible toxic fuel leak immediately surfaced following the incident, but no such leak has been confirmed, rt.com reports. The rocket was initially carrying more than 600 tons of toxic propellants.
No casualties or damage to surroundings structures or the town of Baikonur have been reported.
As RT.com reports, the crashed Proton-M rocket employed a DM-03 booster, which was being used for the first time since December 2010, when another Proton-M rocket with the same booster failed to deliver another three GLONASS satellites into orbit, crashing into the Pacific Ocean 1,500 kilometers from Honolulu.
Photo: Russia Today
Photo: Russia Today
Photo: Russia Today
Photo: Russia Today
UPDATE: Russian Prime Minister Dmitry Medvedev has appointed a special government commission to investigate the causes of the crash and identify any officials who may have been responsible, reports the Christian Science Monitor. Medvedev also directed his government to prepare tougher oversight measures over the space industry to prevent such accidents in future, RIA-Novosti reported.
By Oliver Montenbruck, Chris Rizos, Robert Weber, Georg Weber, Ruth Neilan, and Urs Hugentobler
GPS IS ALMOST 40 YEARS OLD. While mass consumer use of GPS began only within the past decade or so, GPS was “born” during the Labor Day weekend of 1973, when about a dozen military officers and industry analysts under the leadership of Brad Parkinson met to consolidate the concept for a single satellite-based navigation system for the U.S. Department of Defense. Their proposal for NAVSTAR GPS was approved on December 22, 1973. The first satellite to be launched under the GPS program, on July 14, 1974, was the Naval Research Laboratory’s Navigation Technology Satellite (NTS) 1. NTS-2 followed, with a launch on June 23, 1977. These satellites carried payload components similar to those to be used on the subsequent GPS Block I or Navigation Technology Satellites. The first Block I satellite was launched on February 22, 1978, and was followed by nine others. With the launch of the Block II and IIA Operational Satellites and with 24 satellites on orbit, Initial Operational Capability was declared on December 8, 1993. Following testing, Full Operational Capability (FOC) was announced on July 17, 1995.
Whether in reaction to the development of GPS or simply to fulfill the requirement for a system with similar capabilities for its armed forces, the former Soviet Union developed the Global’naya Navigatsionnaya Sputnikovaya Sistema or GLONASS. The first GLONASS satellite was launched on October 12, 1982. By early 1996, a fully populated FOC constellation of 24 satellites was in orbit, but the number of operational satellites dwindled to a handful due to lack of financial support. Eventually the needed funds started flowing again and on December 8, 2011, FOC was again achieved and subsequently maintained.
With the announcement of FOC and the removal of the accuracy-limiting policy of Selective Availability on May 2, 2000, widespread consumer use of GPS took off.
And now GPS is approaching middle age. And like for some humans approaching that milestone desirous of change, a GPS renewal or modernization is under way. New civil and military signals are being transmitted by the Block IIR-M and IIF satellites along with the legacy signals pioneered by the Block I satellites. And new GNSS signals are now coming from the satellites orbited for the Chinese BeiDou Navigation Satellite System, the Japanese Quasi-Zenith Satellite System, and Europe’s Galileo, as well as those from satellite-based augmentation systems. Although it will be some years before full constellations will be transmitting these signals, scientists and engineers are already monitoring and analyzing the new signals to learn how best to use them and how to integrate subsets of them for a wide variety of applications in positioning, navigation, and timing.
In this month’s column, we learn the details of the effort established by the International GNSS Service to support the study of these new signals: the Multi-GNSS Experiment.
“Innovation” is a regular feature that discusses advances in GPS technology andits applications as well as the fundamentals of GPS positioning. The column is coordinated by Richard Langley of the Department of Geodesy and Geomatics Engineering, University of New Brunswick. He welcomes comments and topic ideas. To contact him, see the “Contributing Editors” section on page 4.
Over the past four decades, GPS has evolved from a primarily military navigation system into an indispensable tool not only for society at large, but also for geodetic research and global monitoring of the Earth. And within the past decade, the world of satellite navigation has experienced dramatic changes. With GLONASS, a second GNSS has achieved full operational status; GPS is introducing modernized civil and encrypted navigation signals; and a variety of new navigation constellations are being built up in Asia and Europe.
As of early 2013, Europe has successfully launched a total of four Galileo In-Orbit Validation (IOV) satellites, which are undergoing testing in parallel to the build up and verification of the ground segment. The satellites routinely transmit signals at four frequencies (E1, E5a, E5b, and E6) and offer a variety of publicly accessible pilot and data signals. As a unique feature, Galileo enables tracking of the alternative binary-offset-carrier (AltBOC) signal in the combined E5a+E5b band, which offers superior noise and multipath performance.
Meanwhile, the Chinese BeiDou Satellite Navigation System (BDS; formerly known as Compass) has completed the first stage of its system deployment and declared a regional navigation service for the Asia-Pacific region operational. A total of 14 functioning satellites have been launched so far, which includes five satellites in geostationary orbit (GEO), five satellites in inclined geosynchronous orbit (IGSO), and four in medium-altitude Earth orbit (MEO). These satellites transmit signals in three frequency bands (B1, B2, B3), and tracking of the corresponding open service (OS) signals is already supported by a variety of GNSS receivers. With the release of a B1 OS Interface Control Document (ICD) at the end of 2012, the BeiDou navigation message has become publicly accessible, and users throughout the Asia-Pacific region can now benefit from BeiDou as a supplementary or stand-alone navigation system.
The Japanese Quasi-Zenith Satellite System (QZSS) has, so far, only launched a single satellite but recent political decisions have paved the way for the build up of a mini-constellation of IGSO and GEO satellites. Aside from a high level of compatibility with GPS, QZSS has introduced new signals such as the modernized L1 Civil (L1C) signal and the L-band Experiment (LEX) signal (also known as L6) for high-precision point positioning in the E6 band. Along with this unique set of navigation signals, QZSS provides innovative service features such as the L1 Sub-meter-class Augmentation with Integrity Function (L1-SAIF or L1S) message. Also, QZSS precedes GPS in offering the new Civil Navigation (CNAV) message on L2C and L5, as well as the CNAV2 message on L1C. Long before their planned use in GPS, these messages are now broadcast on a routine basis and contain novel information such as inter-frequency corrections and Earth-orientation parameters.
Last, but not least, GPS has now a total of four Block IIF satellites in orbit that transmit an operational L5 signal for aviation users (and others) and which fly a new generation of highly stable rubidium clocks. While neither L2C nor L5 are transmitted by a full constellation, users and investigators can gradually familiarize themselves with these new signals that will enable encryption-free dual-frequency navigation services for aeronautical and other civil applications.
Within the International GNSS Service (IGS), more than 200 worldwide agencies have, for many years, pooled resources and permanent GNSS station data to generate precise GNSS products in support of Earth science research, multidisciplinary applications, and education. So far, this service has been restricted to two systems — namely, GPS and GLONASS. In recognition of the rapidly evolving GNSS landscape, the IGS has set up the Multi-GNSS Experiment (MGEX) to explore and promote the use of new navigation signals and constellations. It will enable an early familiarization with new GNSS, identify and overcome relevant challenges, and prepare use of emerging navigation systems in routine IGS products. MGEX comprises the build-up of a new network of sensor stations, the characterization of the user equipment and space segment, the development of new concepts and data processing tools, and the generation of early data products for Galileo, QZSS, and BeiDou. MGEX is coordinated by the IGS Multi-GNSS Working Group (MGWG), which interacts closely with other IGS entities, such as the RINEX WG, the Antenna WG, the Data Center WG, and the Infra-structure Committee.
The article starts out with a description of the MGEX network that formed the starting point and initial focus of the overall MGEX project. Following a description of system characterization activities, the current status of multi-GNSS data products and ongoing efforts for the development of new standards for multi-GNSS-related work within the IGS are presented.
Network
Following a call-for-participation released in the summer of 2011, the build up of a new international network of multi-GNSS sensor stations was initiated and has grown substantionally in a short time. By the end of 2012, the MGEX network had comprised approximately 50 stations supporting at least one of the new navigation systems (Galileo, BeiDou, and QZSS) in addition to the legacy GPS, GLONASS, and SBAS systems. At last count, the network now includes 75 stations.
The bulk of the stations is provided by IGS partners such as Bundesamt für Kartographie und Geodäsie (BKG), Centre National d’Etudes Spatiales (CNES), Deutsches GeoForschungsZentrum (GFZ), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Geoscience Australia (GA), the Geospatial Information Authority of Japan (GSI), Institut National de l’Information Géographique et Forestière (IGN), and the Swedish National Land Survey (Lantmaeteriverket, LMV), that have upgraded existing sites with new, multi-GNSS-capable receivers and antennas or started to deploy new multi-GNSS networks (such as the COperative Network for GNSS Observation (CONGO) or CNES’s REseau GNSS pour l’IGS et la Navigation (REGINA) network).
As shown in FIGURE 1, the present set of MGEX stations exhibits almost global coverage, even though a concentration in Europe and a reduced coverage in the Americas and the western Pacific are obvious. However, this situation is expected to improve soon with announced contributions from Geoscience Australia, the Multi-GNSS Monitoring Network (MGM-net) of the Japan Aerospace Exploration Agency (JAXA), and other stations. While most MGEX sites support tracking of Galileo satellites, only a subset of stations provides data for QZSS and BeiDou. In particular, the regional BeiDou constellation (that is, the GEO and IGSO) satellites are not well covered by the current network.
Figure 1. Distribution of MGEX stations supporting tracking of QZSS (blue), Galileo (red), and BeiDou (yellow) as of June 2013.
Further MGEX sites are encouraged and the nomination of sites is still possible through the MGEX submission form under the provision of relevant improvements to the capabilities, coverage, and homogeneity of the overall network.
In terms of equipment, five basic receiver types and seven basic antenna types are employed at the MGEX stations (see TABLES 1 and 2). Observation types provided by the individual receivers have been compiled from summary reports generated by the Astronomical Institute of the University of Bern (AIUB) as part of their routine monitoring of RINEX 3 observation files from MGEX stations.
Table 1. Receiver types in use within the MGEX network (status as of June 2013). Observation types for Galileo (E), BeiDou (C), and QZSS (J) are based on RINEX 3 observation codes as reported in the submitted data files (frequency bands: 1=L1/E1, 2=L2/B1, 5=L5/E5a, 6=E6/B3, 7=E5b/B2, 8=E5ab; signals: C = C/A-code, I = data, Q = pilot, X = data+pilot). They do not necessarily indicate the full tracking capabilities supported by the receivers but rather the observations made available to MGEX users from the respective stations.Table 2. Antenna types employed within the MGEX network (as of June 2013).
Note that no common standard has yet evolved in terms of supported signals and observation types. This causes certain restrictions for data analysis and product generation. As an example, Galileo orbit and clock products will (at least initially) be based on E1/E5a observations due to a limited coverage of E5b and E5ab tracking.
Selected sites (such as UNB and USNO) offer multiple receivers in short- or zero-baseline configurations to facilitate equipment characterization. Further such installations will be added to the MGEX network at the time of the proposed extensions.
While all stations contribute data to offline archives hosted by the Crustal Dynamics Data Information Service (CDDIS), IGN, and BKG for the MGEX project, a selected subset also supports real-time analyses (see FIGURE 2). All real-time streams utilize the Networked Transport of RTCM via Internet Protocol (NTRIP), which has emerged as a standard for real-time GNSS data exchange. A dedicated MGEX caster is hosted by BKG in Frankfurt, where native raw data streams received from the individual sites are converted and encoded in the RTCM3 Multiple-Signal-Message (MSM) format.
Figure 2. Distribution of MGEX real-time stations supporting tracking of QZSS (blue), Galileo (red), and BeiDou (yellow) as of June 2013.
RTCM3-MSM will enable a harmonized framework for multi-GNSS real-time operations and ensure a seamless conversion to the RINEX3 offline data format. The new MGEX NTRIP caster provides a basis to gain early experience with the new MSM format and facilitates a timely adaptation of user software. This is further supported through freeware software modules for data conversion provided by BKG.
System Characterization
While a systematic quality control of the MGEX data has not yet started, first performance assessments of both the ground and space segment have been reported in the literature (see Further Reading). Overall, the measurement quality of the employed multi-GNSS receivers is found to be comparable or even superior to established GPS reference stations. A high performance is, in particular, obtained for unencrypted signals with high chipping rates and bandwidths such as the GPS/QZSS L5 and Galileo AltBOC.
By way of example, FIGURE 3 illustrates the elevation-angle-dependency of pseudorange errors for BeiDou tracking with a Trimble NetR9 receiver as used at numerous MGEX stations. Aside from the expected variation of receiver noise, the analysis reveals a systematic code bias that varies by 0.4-0.6 meters from horizon to zenith and can best be attributed to spacecraft internal multipath.
Figure 3. Code noise and elevation-dependent biases for BeiDou tracking.
An interesting opportunity for system characterization is provided by triple-frequency observations (GPS+QZSS L1/L2/L5, BeiDou B1/B2/B3, Galileo E1/E5a/E5b) made available by a subset of the MGEX network. A thermal variation of inter-frequency biases has earlier been identified for the GPS Block IIF satellites, but a high level of consistency is demonstrated for QZSS, BeiDou, and Galileo (see FIGURE 4).
Figure 4. Triple-frequency combination of Galileo IOV-3 observations.
Products
While the newly established MGEX network forms a mandatory prerequisite for multi-GNSS work within the IGS, the MGEX campaign supports a wider range of activities, which are now being established. Foremost, the generation of orbit and clock products for the new constellations is promoted in coordination with new and established IGS analysis centers.
Initial Galileo IOV products have been provided by CNES/CLS, CODE, and GFZ since mid-2012, and a combined Galileo+QZSS product has been added by Technische Universität München (TUM). Aside from the MGEX network, some of these solutions make complementary use of proprietary multi-GNSS networks to compensate existing coverage limitations and achieve an improved product quality.
TABLE 3 compares selected MGEX orbit products for the Galileo IOV satellites, while FIGURE 5 shows a time series of the difference between the TUM and CODE orbit products for IOV-1 (E11).
Table 3. Inter-comparison of selected MGEX orbit products for the Galileo IOV satellites. (IOV-1 (E11), DOY 323-329, 2012). Orbit differences (mean ± standard deviation) in radial (R), along-track (T) and cross-track (N) directions are provided in the upper right cells, 3D RMS position differences in the lower left. All values are in units of meters.Figure 5. Difference of MGEX Galileo IOV-1 (E11) orbit products from TUM and CODE for DOY 232-239, 2012 (R: radial direction, T: along-track direction, N: cross-track direction).
TABLE 4 shows the residuals of Galileo IOV-1/2 satellite laser ranging measurements (mean ± standard deviation) relative to the GNSS-based orbit products (days of year (DOY) 323-329, 2012).
Table 4. Satellite laser ranging residuals (mean ± standard deviation) for Galileo IOV-1/2 orbit products (DOY 323-329, 2012). Units are centimeters.
FIGURE 6 shows a time series of the differences between TUM orbit products for QZS-1 and precise ephemerides computed by the Japan Aerospace Exploration Agency (JAXA) for DOY 027-033, 2013. It demonstrates consistency at the 0.5-meter level, which already represents an important accomplishment, given the sparse subset of QZSS-capable MGEX stations available at the time. Further improvements are expected as the MGEX network continues to grow.
Figure 6. Comparison of TUM MGEX orbit products of QZS-1 with precise ephemerides of JAXA for DOY 027-033, 2013.
Concerning the Chinese BeiDou system, which has now reached initial operational capability for a regional service, early orbit and clock determination results have been reported by various Chinese and European researchers using data from dedicated regional sensor station networks. An effort will be made to promote the extension of the BeiDou tracking capabilities within the MGEX network and to make MGEX-only or mixed network-based orbit and clock products for BeiDou accessible to a wider user community through the MGEX data centers.
Given the late public availability of Galileo and BeiDou broadcast navigation messages, the MGEX orbit and clock products constitute a significant promotion for the early use of all available navigation systems. Aside from initial positioning experiments, they provide a basis for the in-depth characterization of both the space and user segment, and, it is hoped, will facilitate an improved interaction with system providers. Early applications of MGEX multi-GNSS products and observations have, for example, been reported at conferences and in journals (see Further Reading).
Standardization
In support of MGEX, the Multi-GNSS WG interacts closely with other IGS working groups to coordinate data formats, processing standards, and applicable models for use in multi-GNSS work. Examples include necessary RINEX 3 and RTCM3 extensions for full support of new GNSS signals and tracking modes as well as the rapidly growing set of diverse broadcast navigation data.
Another focus of current work addresses the proper modeling of antenna offsets and phase patterns for receiver and satellite antennas, along with documentation of constellation-specific spacecraft coordinate systems and attitude modes. This work is performed in close coordination with the IGS Antenna WG. Among others, conventional antenna phase center offsets (see TABLE 5) have been agreed upon, which will enable consistent processing of MGEX observations until the release of official information by the Galileo and BeiDou program offices.
Table 5. Conventional antenna offsets from the spacecraft center of mass for processing Galileo IOV and BeiDou observations. All values refer to the spacecraft coordinate system. Units are meters.
Public Outreach
As a central point for exchange of MGEX-related information with the user community, a dedicated website has been established at the IGS Central Bureau (see FIGURE 7). The new website provides an overview of available MGEX data and products with direct links to the respective archives at IGS data and product centers. Furthermore, users are provided with up-to-date information on the status of the emerging navigation satellite systems as well as recommended parameters (such as antenna offsets) for harmonized and consistent processing of MGEX observations.
Figure 7. Homepage of the IGS Multi-GNSS Experiment at http://igs.org/mgex.
Through individual members, the Multi-GNSS WG is represented on other boards and bodies such as the International Committee on GNSS, the International Association of Geodesy, and the Multi-GNSS Asia project.
Summary and Conclusions
As part of its continued effort to provide the highest quality data and products for all satellite navigation systems, the IGS has initiated the Multi-GNSS Experiment. MGEX supports early work with new signals and constellations. It enables a timely preparation of IGS analysis centers as well as the user community to expand from GPS/GLONASS towards full multi-GNSS processing.
Within the first year of MGEX, substantial progress has already been made. In particular, a global network of multi-GNSS receivers has been established in parallel with the existing core IGS network and by upgrading existing sites with new multi-GNSS equipment. The MGEX network forms the backbone for all other activities, such as system characterization and product generation. Aside from offline data provisions, a substantial fraction of MGEX stations are already offering real-time data streams, which paves the way for a rapid extension of the upcoming IGS real-time pilot service to Galileo and possibly other constellations. A limited number of analysis centers have already started to provide orbit and clock products for Galileo and/or QZSS as a basis for precise positioning applications. In addition to initial positioning experiments, they will provide a basis for the in-depth characterization of both the space and user segment, and help facilitate an improved interaction with system providers.
Upcoming activities will focus on the systematic incorporation of the BeiDou navigation satellite system. While BeiDou is the third constellation to reach an operational system status after GPS and GLONASS, it is not well covered by the current MGEX tracking network. Along with the targeted incorporation of BeiDou-capable reference stations (particularly in the Asia-Pacific region), the generation and provision of related orbit and clock products will be promoted to facilitate a timely use of BeiDou by the geodetic community.
Subject to active participation by a sufficient number of analysis centers, the MGEX project will eventually transition into an IGS pilot project offering operational data products of Galileo, QZSS, and BeiDou within the next few years.
OLIVER MONTENBRUCK is the head of the GNSS Technology and Navigation Group at DLR’s German Space Operations Center. He chairs the IGS Multi-GNSS Working Group and coordinates the MGEX Multi-GNSS Experiment.
CHRIS RIZOS is a professor at the University of New South Wales, Sydney, Australia; president of the International Association of Geodesy; co-chair of the Multi-GNSS Asia Steering Committee; and a member of the executive and governing board of the IGS.
ROBERT WEBER is an associate professor at the Department of Geodesy and Geoinformation, TU Vienna, and former chair of the IGS GNSS Working Group.
GEORG WEBER is the scientific director in the Department of Geodesy at the German Federal Agency for Cartography and Geodesy (BKG). He is a member of the IGS Real-time Working Group and the Radio Technical Commission for Maritime (RTCM) Services Special Committee (SC) 104 on Differential Global Navigation Satellite Systems (DGNSS).
RUTH NEILAN is the director of the Central Bureau of the IGS, vice-chair of the Global Geodetic Observing System Coordinating Board, and co-chair of Working Group D, Reference Frames, Timing and Applications, of the United Nation’s International Committee on GNSS.
URS HUGENTOBLER is a professor at the Institute of Astronomical and Physical Geodesy, TUM, Munich. He is the chair of the IGS Governing Board.
FURTHER READING
• The IGS MGEX Campaign
“The IGS MGEX Experiment as a Milestone for a Comprehensive Multi-GNSS Service” by C. Rizos, O. Montenbruck, R. Weber, G. Weber, R. Neilan, and U. Hugentobler in Proceedings of The Institute of Navigation 2013 Pacific PNT Meeting, Honolulu, Hawaii, April 23 –25, 2013, pp. 289–295.
“Multi–GNSS Working Group” by O. Montenbruck in International GNSS Service Technical Report 2012, edited by R. Dach and Y. Jean and published by the IGS Central Bureau, April 2013. Pp. 163–170.
“IGS M-GEX – The IGS Multi-GNSS Global Experiment” by R. Weber, U. Hugentobler, and R. Neilan in Proceedings of the 3rd International Colloquium on Scientific and Fundamental Aspects of the Galileo Programme, Copenhagen, 31 August – 2 September, 2011.
“Initial Assessment of the COMPASS/BeiDou-2 Regional Navigation Satellite System” by O. Montenbruck, A. Hauschild, P. Steigenberger, U. Hugentobler, P. Teunissen, and S. Nakamura in GPS Solutions, Vol. 17, No. 2, April 2013, pp. 211–222, doi: 10.1007/s10291-012-0272-x.
“Orbit and Clock Determination of QZS-1 Based on the CONGO Network” by P. Steigenberger, A. Hauschild, O. Montenbruck, C. Rodriguez-Solano, and U. Hugentobler in Navigation – Journal of The Institute of Navigation, Vol. 60, No. 1, Spring 2013, pp. 31–40.
• RTCM and NTRIP Formats
Differential GNSS (Global Navigation Satellite Systems) Services, Version 3, RTCM 10403.2, published by Radio Technical Commission for Maritime Services, Arlington, Virginia, February 1, 2013.
“The RTCM Multiple Signal Messages: A New Step in GNSS Data Standardization” by A. Boriskin, D. Kozlov, and G. Zyryanov in Proceedings of ION GNSS 2012, the 25th International Technical Meeting of The Satellite Division of the Institute of Navigation, Nashville, Tennessee, September 17–21, 2012, pp. 2947–2955.
“Networked Transport of RTCM via Internet Protocol (Ntrip) – IP-Streaming for Real-time GNSS Applications” by G. Weber, D. Dettmering, H. Gebhard, and R. Kalafus in Proceedings of ION GPS 2005, the 18th International Technical Meeting of the Satellite Division of The Institute of Navigation, Long Beach, California, September 13–16, 2005, pp. 2243–2247.
The first satellite of the Indian Regional Navigation Satellite System (IRNSS) was successfully launched today.
The launch of IRNSS-1A occurred on schedule at is scheduled for 18:13 UTC from the spaceport of Sriharikota. Liftoff from the first launch pad at the Satish Dhawan Space Centre occurred on schedule at 18:11 UTC. The 1,425-kg satellite was launched by the XL version of India’s rocket PSLV-C22, or Polar Satellite Launch Vehicle.
Solar panel deployment was confirmed and the satellite has power and is operating nominally according to reports.
The IRNSS-1A satellite is the first of seven that will make up the IRNSS. The constellation will consist of four satellites in geosynchronous orbits inclined at 29 degrees, with three more in geostationary orbit. IRNSS-1A is one of the geosynchronous satellites, and is expected to be positioned at a longitude of 55 degrees east.
The European Space Agency (ESA) has released detailed views of the next batch of Galileo satellites, the first of which cuurently performs under simulated space conditions at the ESTEC technical center in Noordwijk, the Netherlands.
The first Galileo Full Operational Capability (FOC) satellite is functionally identical to the four Galileo In-Orbit Validation satellites already in orbit, but has been built by a separate industrial team. All 22 FOC satellites so far procured by ESA have as prime contractor OHB in Bremen, Germany; Surrey Satellite Technology Ltd. in Guildford, UK, produces the navigation payloads. The photos shown here were taken at OHB.
The satellite’s body measures 2.5 x 1.2 x 1.1 meters (8.2 x 3.9 x 3.6 feet), and it weighs approximately 733 kilos (1,616 pounds). Atop it in these photographs (although on the underside when orbiting Earth) is the circular L-band antenna that will continuously broadcast navigation messages.
The smaller, hexagonal antenna beside it will pick up emergency messages from vessels in distress and relay location and other information to search and rescue authorities, contributing to the international Cospas–Sarsat system.
A second Galileo FOC satellite is due to also travel to ESTEC this summer, preparing for a launch later this year.
L-Band antenna of the FOC satellite. Photo: ESAemergency signal antenna of the FOC satellite. Photo: ESA
L2, L5 CNAV Testing
The U.S. Air Force Space Command began testing civil navigation (CNAV)capabilities on the GPS L2 and L5 signals on June 15 and was scheduled to continue until June 29. Civil users and manufacturers were invited to participate.
According to the GPS Directorate, the CNAV live-sky testing program will span several years and will evolve to support GPS enterprise and modernized civil navigation performance objectives. Objectives include:
◾ Verify and validate the CNAV requirements specified IS-GPS-200F and IS-GPS-705B.
◾ Facilitate the development of robust IS-compliant L2C and L5 civil receivers.
More information about the testing is available in a 52-page PDF, including sections on test strategy, event conditions and constraints, operational environment, test support resources and data collection, evaluation methodology, risk assessment, and reporting.
The L2 CNAV data is an upgraded version of the original NAV navigation message. It contains higher precision representation and nominally more accurate data than the NAV data. Two out of every four packets are ephemeris data and at least one of every four packets will include clock data, but the design allows for a wide variety of packets to be transmitted. Only a fraction of the available packet types have been defined; this enables the system to grow and incorporate advances.
One packet contains a GPS-to-GNSS time offset, enabling interoperability with other global time-transfer systems such as Galileo and GLONASS, both of which are supported. The extra bandwidth enables the inclusion of a packet for differential correction. Every packet contains an alert flag, to be set if the satellite data cannot be trusted. Users will know within six seconds if a satellite is no longer usable, important data for safety-of-life applications such as aviation.
The system is designed to support 63 satellites, compared with 32 in the L1 NAV message.
Possible New GPS Launch Option
The U.S. Air Force Space and Missile Systems Center (SMC) has signed a Cooperative Research and Development Agreement with Space Exploration Technologies Corp., better known as SpaceX, as part of the company’s effort to certify its Falcon 9 v1.1 Launch System for National Security Space (NSS) missions.
SMC and SpaceX will look at the Falcon’s flight history, vehicle design, reliability, safety systems, and other aspects. Once the evaluation is complete, the SMC commander will determine whether SpaceX has the capability to successfully launch NSS missions using the Falcon 9 v1.1.
Currently, United Launch Alliance’s Delta IV and Atlas V are the only certified launch vehicles capable of lifting NSS payloads — such as the GPS satellites — into orbit. The addition of multiple certified launch vehicles provides more options to place needed capabilities on orbit. While certification does not guarantee a contract award, it does enable a company to compete for launch contracts. Those contracts could be awarded as early as Fiscal Year 2015 with launch services provided as early as FY 2017.
GPS III Funds Cut, GPS IV on Horizon?
According to a U.S. Department of Defense (DoD) spending plan released on June 1, space programs were relatively protected in an environment of across-the-board budget cuts known as sequestration. Specifically, although the budget for GPS III has been reduced for both 2013 and 2014, the reductions still allow the proposed program to stay on course. The cuts amount to about $58 million from GPS III and its associated ground system.
Congressional lawmakers proposed spending $77 million less next year for the GPS III satellite and ground systems than proposed by the Air Force, which asked for nearly $1.1 billion.
Currently, the Air Force has eight GPS III satellites contracted with Lockheed Martin Space Systems, and current plans call for the purchase of 12 further satellites with improved capabilities.
GPS IV. Gen. William Shelton, commander of Air Force Space Command, floated the possibility of a new look for the constellation on Capitol Hill. In an April 25 House hearing, Shelton said the Air Force will study this fall whether to buy another 12 GPS III craft or move on to a new generation of satellites.
“Would it be better to continue [GPS III] as opposed to starting a whole new fourth generation?” asked Representative Doug Lamborn of Colorado. “That’s the decision we will have to make in the fall,” replied Shelton. “It seems like the answer would be ‘yes’ but we will study that.”
A key aspect of the next-next gen satellite would have to be dual-launch capability. The reduction in expense this would furnish is in higher and higher demand as time goes by. Both Lockheed and Boeing are reportedly in talks with the Air Force regarding IV.
System Briefs
GLONASS Embezzle Imbroglio. The Russian Federal Security Service is investigating the embezzlement of billions of rubles from the construction of the GLONASS center in Korolyov, a town outside Moscow, as reported by Izvestia.
Construction of the GLONASS control and support center began in June 2010 on the site used by TsNIImash, the head research company of Russia’s federal space agency. The center was supposed to hold equipment for collecting and processing the data supplied by the GLONASS global network.
The construction was financed by a federal program, with 1.050 billion ($33.22 million) allocated for the project. By the end of 2010, it came to light that construction costs had been overstated, Izvestia reports. An expert appraisal revealed that the contractor had rigged the costs. The government did not allocate additional funds, so construction was suspended in December 2011 when the Federal GLONASS Program for 2002-–2011 ended. The construction of the building has never been completed.
In November 2012, the general designer of GLONASS, Yuri Urlichich, was dismissed from his post as a result of the scandal.
IRNSS Nav Center, July Launch. The Indian Space Research Organization (ISRO) Navigation Centre for the Indian Regional Navigation Satellite System (IRNSS) was inaugurated May 28, at the Deep Space Network complex at Byalalu, near Bangalore, India.
IRNSS, an independent navigation satellite system being developed by India, will have a constellation of seven satellites in geostationary and inclined geosynchronous orbits. IRNSS coverage will extend over India and the southeast Asia region. The ISRO Navigation Centre (INC) is responsible for providing the time reference, generation of navigation messages, and monitoring and control of ground facilities including ranging stations of IRNSS. IRNSS will establish a network of 21 ranging stations geographically distributed primarily across India to provide data for the orbit determination of IRNSS satellites and monitoring of the navigation signals.
On June 15, India’s Economic Times reported that a new launch date (postponed from previously announced June 11) was set for IRNSS-R1A or 1A, the first IRNSS satellite: July 1 at 18:13 UTC.
Beidou Jammed. A Beidou satellite is now believed to have experienced interference from a complex electromagnetic environment, which cut off signal transmissions in 2007, China’s People’s Daily reported. A team of scientists was able to overcome the interference issue in less than three months by 2008.
Wang Feixue, a scientist specializing in the Beidou navigation system and a senior colonel in the People’s Liberation Army said, “Had they not been able to recover the signal within three months, future satellite launches would have been indefinitely delayed. And satellites already launched would have been put out of operation.”
EGNOS Contract. A new European Geostationary Navigation Overlay Service (EGNOS) service provision contract was signed June 26 at the European Commission Vice President Antonio Tajani’s office in Brussels. The contractee is again the European Satellite Services Provider (ESSP), founded in 2001and in 2008 transformed into ESSP SAS and moved from Brussels to Toulouse.
Its shareholders are seven European air navigation service providers: Aeropuertos Espanoles y Navegacion Aerea (Spain), Deutsche Flugsicherung GmbH (Germany), Direction générale de l’Aviation civile (France), Ente Nazionale Di Assistenza Al Volo (Italy), National Air Traffic Services (UK), Navegação Aérea de Portugal, and Skyguide (Switzerland).
I recently attended the Fourth China Satellite Navigation Conference (CSNC, held May 15–17 in Wuhan, China), as an invited speaker and panelist. I had attended the third CSNC last year in Guangzho, and as expected this year’s was a little bigger and a little better. The Chinese GNSS industry is growing quickly, as evidenced by the more than 2000 attendees with as many as 10 simultaneous sessions at some times, with more than 200 presentations over three days, and nearly 150 exhibitors on the show floor. The conference is mainly attended by Chinese, but they are working hard to attract an international audience by providing simultaneous translation of all presentations, and dual-screen projection for slides in English and Chinese if the author chooses.
I couldn’t possibly see everything, so I chose to spend most of my time in a series of sessions on industrial policy, regulations, standards, and intellectual property. I thought those sessions would provide the most unique information this conference had to offer. I expected to hear a lot of standard or official position statements without much audience discussion, but I was pleasantly surprised by the level of information from personal experience that the speakers offered and the amount of lively debate that often followed the presentations. The simultaneous translation was essential and not only allowed me to follow but created the opportunity for multi-language Q&A which allowed more complex questions to be asked.
I was particularly interested in understanding what changes were going to occur since the full release of the BeiDou Interface Controld Document (ICD) in December. One thing I noticed right away is that the term Compass has pretty much gone away. The official name, and what everyone used in their presentation, is BDS. I am not quite sure I follow the methodology, but it’s an abbreviation for the BeiDou Satellite System. I would certainly recommend to anyone meeting with Chinese business associates that you appear very up to date by using BDS instead of Compass in all your presentations, oral, written or PowerPoint.
The changing of the official name is just the first ripple in what I expect will be a wave of changes in the BDS industry (see, I learn fast). One of the most interesting talks was given by Hua Xu, whose affiliation was given in the English program as “BDS specific policies and regulations expert team, ex-director of the policy and regulations Division of Development and Reform Commission.” His talk was entitled “Thoughts of perfecting China’s BDS Industry System Construction.” He related several interesting anecdotes about the history of the satellite program, going back many years, all the way to the Cultural Revolution of the 1970s. As an example of how different the Chinese setting is for legal issues, he told us that in China, if a car hits a pedestrian, the car driver has to pay damages regardless of fault, because since he is driving the car, and the car damaged the pedestrian, he must accept responsibility. Mr. Xu spent more time talking about how China’s GNSS industry must grow in terms of industrial capability, intellectual property, and mass production, and how the government is encouraging that growth.
To date, that growth has been very rapid, as embodied by a vast array of small companies focusing on domestic Chinese applications of BDS, in particular in survey and mapping and in search and rescue. The growth impetus now moves to the automotive sector, where there is continued investment by both the national government and regional governments to promote the use of BDS in transportation projects involving trucks, taxis, and government vehicles. Some may view this as protectionist, due to the approved vendor lists and subsidies that are provided, but I think it is just a natural effort to create local centers of excellence and jobs in a new technology; this process occurs all over the world. The companies that are in this business are the 150 or so who exhibited on the CSNC show floor, and they are the little tigers of my title.
Most of the names of the little tigers are not that familiar outside of China: unicore, BDstar, Olinkstar, and many more. They have developed their own GPS+BDS chips and are selling them in moderate quantities of thousands for domestic customers. At CSNC, they presented lots of results that clearly show the advantages of multi-GNSS (GPS+BDS) within today’s BDS regional coverage area. Furthermore, the accuracy and time-to-first-fix performance of their solutions is comparable to the overall market. However, as market needs in China grow from thousands of units to millions of consumer devices, the little tigers are not quite ready yet to support the Lenovos (computers), HTCs (smartphones) and Huaweis (mobile phones and tablets).
But China wants to see BDS in all those consumer devices, to demonstrate to the world the benefit of BDS; hence the ICD was released in December. The ICD release opened the gate to China’s domestic market that previously was solely hunted by the little tigers. The wolves were waiting at the gate and they have charged in. Broadcomm, CSR, Trimble, NovAtel, and others have already publicly announced BDS support in their mainstream products, in the first few months following the release.
This was the topic of the discussions in CSNC that were most revealing for a foreigner like me to hear. I was ready to ask the tough question of what the future holds in the consumer market, because I figured no one else would. But much to my surprise, the moderator of the session put up a slide that translated to: “B1 ICD was released while Regional System is officially operational, will affect domestic BDS receiver industry? Pros? Cons?” (See opening photo.)
The ensuing discussion was quite lively but polite on both sides of the issue. Would subsidies continue for domestic suppliers? How could local companies hope to attract investment to scale up with international competition? Where could Chinese companies carve out intellectual property to protect their inventions? What could that government really do without running afoul of the World Trade Organization?
Many more questions were raised than answers arrived at, and I think most of the really interesting discussions took place away from the microphones and the simultaneous translation. So I cannot provide them for you.
Even without answers, the act of discussion was enlightening. I think the fact that these discussions are happening in public forums indicates the growth and transformation of Chinese society. There were finance people, engineers, businessmen, government regulators, all debating a difficult topic.
I don’t know the answers, but the little tigers know that the wolves are coming. And they are not running in fear. The openness of the internal debate within China indicates that the little tigers are working on a new plan, and no one should assume that the wolves are going to win. The competition in the domestic Chinese market — the very largest market, by far, of any in the world — is going to be very interesting over the next few months and years.
Greg Turetzky is a principal engineer at Intel responsible for strategic business development in Intel’s Wireless Communication Group focusing on location. He has more than 25 years of experience in the GNSS industry at JHU-APL, Stanford Telecom, Trimble, SiRF, and CSR. With this issue, he joins GPS World’s Editorial Advisory Board.
The statements, views, and opinions presented in this article are those of the author and are not endorsed by, nor do they necessarily reflect, the opinions of the author’s present and/or former employers or any other organization the author may be associated with.
GLONASS satellites 48, 49, and 50 are expected to launch at 02:38 UTC on July 2. Live launch coverage will be provided by TsENKI, the Center (for Operation) of Ground-based Space Infrastructure, starting at 01:00 UTC. Also, launch updates are available here.
Launch of the first satellite for the Indian Regional Navigation Satellite System (IRNSS) is scheduled for 18:13 UTC on July 1. Launch rehearsal has been completed successfully. The 64-hour countdown is expected to start at 7:11 (IST) tomorrow, June 29, and the launch will take place from the spaceport of Sriharikota. The 1,425 kg satellite will be launched by the XL version of India’s rocket PSLV-C22.
QinetiQ and Septentrio jointly announced today that a milestone in the Galileo European Navigation Satellite System’s development and deployment program has been achieved. On March 12, staff at the European Space Agency at ESTEC, Noordwijk, The Netherlands, achieved the first navigation solution using only the encrypted Galileo Public Regulated Service (PRS) signals broadcast by the four Galileo In-Orbit Validation (IOV) satellites launched in 2011 and 2012. Septentrio and QinetiQ, working in close partnership, developed one of the two PRS test user receivers used in this historic first test.
PRS positioning was achieved using the Galileo PRS Test User Receiver (TUR-P) jointly developed by Septentrio and QinetiQ under an ESA contract. For the reception test, the receiver was installed in the PRS test facility in ESTEC and operated by technical experts from ESA. Positioning accuracy of ~10 meters was achieved, excellent for a first test so early in the system’s deployment. The TUR-P now continues to be used as part of the campaigns running during the Galileo In Orbit Validation Phase.
This milestone builds on a number of previous major Septentrio/QinetiQ achievements including:
First laboratory demonstration of the PRS signal acquisition and tracking in QinetiQ (Malvern, UK, 2006).
Successful RF compatibility test between a Galileo payload and the TUR-P (Portsmouth, UK, 2010).
Successful Galileo end-to-end system test including the Galileo Ground Mission Segment (GMS) and its key management facilities, satellite and TUR- P (Rome, Italy, 2011).
First successful reception and processing of the PRS signal from space (Fucino, Italy, 2012).
As key, long-term contributors to the Galileo program, Septentrio and QinetiQ have worked closely with ESA, the European GNSS Agency (GSA) and European industrial partners since 2003.
“Following last year’s first successful reception and processing of PRS signals from Galileo satellites, I am very pleased to see the program moving forward successfully,” said Leo Quinn, CEO of QinetiQ. “Achieving a first PRS-only Galileo navigation solution is a major achievement. With positioning, navigation and timing services increasingly critical to the safety, security and economic activity of UK and our European neighbours QinetiQ are very proud to be contributing to the development of Europe’s first secured satellite navigation services.
“This milestone is another important step towards the launch of operational Galileo services and will continue to build confidence in both prospective users and the industrial supply base. It showcases QinetiQ’s capabilities in this field and signals the way towards the production of exciting new solutions for critical navigation and timing applications.”
“Today, together with our partners, we take another decisive step in the early availability of commercial PRS receivers and Septentrio is extremely proud of this historic milestone for the Galileo program,” commented Peter Grognard, Septentrio’s founder and CEO. “This builds on a list of major achievements for Septentrio since the reception of the first Galileo signal from space in 2006. We are delighted to continue the excellent collaboration with ESA and to contribute to this ambitious European project.”
The launch of the next three GLONASS-M satellites is scheduled for July 2, according to an announcement by Roscosmos, the Russian Federal Space Agency.
A Proton-M launch vehicle with the upper stage DM-03 and three satellites was rolled out from Baikonur Cosmodrome’s assembly and test facility site 92A-50 on June 28 to launch pad 81. The decision was made to transport the launch vehicle at a meeting of the technical guidance of the State Commission, held the day before.
QinetiQ
