One of the GNSS controversies of the past year ended, not with a bang nor with a whimper, but like the fog, silently creeping away on its little cat feet. The UK patent applications against the interoperative GPS/Galileo signal design appear to have been dropped.
Vague rumblings emerged throughout spring and summer this year that two British technologists, backed by the U.K. Ministry Defense, had filed patents on the future interoperable GPS and Galileo binary-offset carrier signal designs. If granted and enforced, the patents would have severely disrupted modernization plans for both systems and levied unexpected costs upon receiver manufacturers. A company called Ploughshare Innovations Ltd. started contacting manufacturers and asking for payment of royalties, based on the patent filings.
After significant uproar and negotiations before and behind the scenes, it now appears that the initiative has been quietly scuttled. The U.S. Patent Office file on application number 11/774,412, Modulation Signals for a Satellite Navigation System, on the Patent Office’s website, now reads “Expressly Abandoned — During Examination.” The status is dated September 16, 2012, some time ago, but none of the parties involved, whether as filers or negotiators, has made any public announcement about it.
Both Sides Now. Checking the European Patent Office and its registry — which is no trivial task of website navigation — turns up a note, dated September 24, under the docket for EP1830199, Modulations Signals for a Satellite Navigation System. The note states “Patent surrendered.” A few days later, another note: “Lapsed in a contracting state announced via postgrant inform. From Nat. Office to EPO,” with further information to the effect of “lapse because of failure to submit a translation or the description or to pay the fee within the prescribed time limit.”
For good measure, a final docket note on October 3: “Lapsed due to resignation by the proprietor.”
Lockheed Martin Logs Enviro OK on GPS III Sat
The Lockheed Martin team developing the U.S. Air Force’s GPS III satellites has completed thermal vacuum testing for the Navigation Payload Element (NPE) of the GPS III Non-Flight Satellite Testbed (GNST). The milestone is one of several environmental tests verifying the navigation payload’s quality of workmanship and increased performance compared to the current generation of satellites.
During thermal vacuum testing, the navigation payload’s performance was proven in a vacuum environment at the extreme hot and cold temperatures it will experience on orbit to ensure it will operate as planned once in space. Following the test, the NPE will now be integrated with the GNST for final satellite level testing.
The GNST is a full-sized prototype of a GPS III satellite used to identify and solve development issues prior to integration and test of the first space vehicle. The approach significantly reduces risk, improves production predictability, increases mission assurance and lowers overall program costs. Following integration and test at Lockheed Martin’s GPS Processing Facility (GPF) near Denver, the GNST will be shipped to Cape Canaveral Air Force Station, Florida, for risk reduction activities at the launch site.
Lockheed Martin is on contract to deliver the first four GPS III satellites for launch. The Air Force plans to purchase up to 32 GPS III satellites.
Galileo IOV Satellites in Position
The Galileo In-Orbit Validation (IOV) satellites launched on October 12 (Flight Model 3 and 4), have now been positioned in their designated orbits, according to tracking data from the U.S. Joint Space Operations Center. A plot of the IOV constellation is now available at http://gge.unb.ca/test/Galileo.argper.690.432000.pdf.
The four IOV satellites are in two orbital planes separated by about 120 degrees. Within each plane, the satellites are separated by about 40 degrees. This orbital arrangement will allow the four satellites to be simultaneously tracked for periods of time by GNSS monitoring stations, permitting positioning tests using only IOV data to be carried out. However, no signals from FM3 or FM4 have yet been detected by stations of the International GNSS Service.
Activities of the European Navigation Support Office
Headshot: Werner Enderle
By Werner Enderle
The European Space Operations Centre (ESOC) in Darmstadt, Germany operates spacecraft on behalf of the European Space Agency (ESA) and maintains the ground facilities and expertise for ESA and other institutional and commercial customers. ESOC is composed of two departments: the Mission Operations Department and the Ground Systems Engineering Department, of which the Navigation Support Office is an integral part. The main objectives of the Navigation Support Office (NSO)are the provision of expertise for high-accuracy navigation, satellite geodesy, and the generation of related products and services for all ESA missions and for third-party customers, as well as supporting the European GNSS Programmes: Galileo and EGNOS.
In 2013, the NSO will conduct a number of projects and activities, described here.
European GNSS
The Navigation Office provides support in the area of data processing and analysis, performance analysis. It performs operational orbit predictions for the International Satellite Laser Ranging Service (ILRS), operational precise/rapid orbit and clock determination, computation of antenna patterns, and provides support to Galileo Sensor Stations (GSS) site deployment and to Ranging and Integrity Monitoring Station (RIMS) deployment. It also provides consultancy on modeling and data processing, mission analysis for the constellation, orbit validation activities for orbits and clocks, ionosphere, group delays, and intersystem biases, and is involved in the generation of the Galileo Geodetic Reference Frame. Furthermore, the Office participated in European Commission studies for the Galileo Commercial Service.
Earth Observation Missions
A number of European and American missions have been equipped with radar altimeter instruments that observe the level of the sea surface from space. To do this, the height component of the satellite orbits needs to be determined with centimeter-accuracy, matching the accuracy of the altimeter observations. The NSO provides support to Precise Orbit Determination (POD), evaluation, analysis and improvement of models and standards, as well as instrument calibration (radar altimeter and GNSS antenna).
Examples of missions already supported include ERS, Envisat, Cryosat, GOCE and also non-ESA missions JASON 1&2. Solutions with multiple simultaneous data types (GNSS, SLR, DORIS, altimetry, S-band range, Doppler, and angle tracking) are typically performed, allowing the alignment of different reference frames and estimation of inter-system and instrument biases. Based on all these capabilities, the NSO is one of the leading institutions for low-Earth orbiting (LEO) satellite POD activities and very well suited for supporting the upcoming European programme for Earth Observation, called Global Monitoring for Environment and Security (GMES) and its related Sentinel satellite missions.
Automated Transfer Vehicle
The Automated Transfer Vehicle (ATV) is part of the European contribution to the International Space Station (ISS) program. The main tasks of the ATV are to provide logistics supply, station re-boost and ISS waste retrieval. The rendezvous of the ATV and ISS is based on a real-time on-board relative navigation concept, using GPS data from receivers of ISS and ATV. The NSO conducts in this context simulations before the flight and also post facto performance analysis of the relative orbit determination accuracy to support the ATV missions.
Space Situation Awareness
An important atmospheric application of GNSS data is the monitoring of ionospheric activity (total electron content or TEC). Dual-frequency GNSS signals enable direct measurement of this parameter, and by merging the data from hundreds of globally distributed GPS receivers, detailed maps of the TEC and its evolution as a function of time can be constructed. Such maps have been computed routinely for many years. FIGURE 1 shows an example. The importance of these products lies in the fact that high solar activity leads to high TEC values, which can seriously disturb satellite communications. The NSO provides ionospheric TEC maps to the scientific community.
International GNSS Services
ESA/ESOC was one of the founding members of the IGS, and at the time the NSO was implemented at ESOC, all of the IGS activities were transferred to the NSO. ESA Analysis Centre products are among the best products available from the individual IGS analysis centres. Secondly, the ESA products are among the few multi-constellation GNSS products. ESA was the first IGS analysis centre to provide a consistent set of orbit and clock products for all available GNSS satellites. These products constituted the very first products that have been used for true GNSS precise point positioning.
The sampling rate of the ESA final GPS+GLONASS clock product is 30 seconds. FIGURE 2 shows the statistics of a kinematic PPP analysis using the ESA GNSS clocks for three different cases. The ESA/ESOC IGS Analysis centre contributes to all of the core IGS analysis centre products: Final GNSS (GPS+GLONASS) products provided weekly based on 24-hour solutions using 150 stations from true GNSS solutions simultaneously and fully consistently processing GPS and GLONASS measurements for a total of around 55 satellites, consisting of orbits, clocks, coordinates, ionosphere, and Earth-orientation parameters (EOPs). Also Rapid GNSS (GPS+GLONASS) products (available within 3 hours after the end of the observation day) and Ultra-Rapid GNSS (GPS+GLONASS) products (4 times per day, available within 3 hours after the end of the observation interval) are provided. These products are publicly available to the scientific community, being published at several data servers, such as the CDDIS at NASA’s Goddard Space Flight Center. They are also finding very frequent application in testing of experimental and commercial applications, and have become the standard reference for all high-precision GNSS applications.
Figure 2. Kinematic PPP analysis using ESA GNSS clocks: GLONASS-only PPP (red); GPS-only, (green), and a truee GNSS-PP (blue).
Third-Party Activities
Different customers have different needs. One important customer for the Navigation Facility is the Metop mission operated by EUMETSAT. For the exploitation of its GNSS Receiver for Atmospheric Sounding (GRAS) payload, which delivers atmospheric profiles to the European Met offices, EUMETSAT requires GPS products with a guarantee on accuracy, availability and latency. To deliver this service, the Navigation Facility now hosts the operation of the GRAS Ground Support Network (GSN), which is a dedicated network of 45 stations. It has been operating successfully for five years, delivering products with a latency of only 45 minutes, and an availability of better than 99 percent. Based on these, EUMETSAT delivers a daily set of more than 500 atmospheric profiles (and double that number as soon as Metop-2 will be operational) to the European Met offices, a data set that has already become one of the key elements in numerical weather prediction.
Real-Time Processing
Over the last 10 years, ESOC has embarked on a program to build a Real Time GNSS software infrastructure. The main justification for this effort is the realization that the delivery of precise GNSS products in real-time processing will become increasingly more important for the user community. ESOC needs to be at the forefront of these developments, particularly with respect to products related to Galileo. The system for REal TIme NAvigation (RETINA) has been modelled after ESOC’s experience in real-time satellite control systems and includes many of the elements for data processing, archiving, and visualization that are common to such systems. In particular, it implements a specially designed circular filing system for streaming data, allowing maintenance-free operations for processing and archiving of data and products, and seamless transitions from historical to live data processing.
The investment in GNSS software and receiver infrastructure has enabled ESOC to participate in the IGS Real Time Pilot Project, assuming the roles of Real Time Analysis Centre and Analysis Centre Coordinator. In the latter role, ESOC has been generating and disseminating the IGS Real Time Combination stream after processing the real-time solutions from up to ten analysis centres. Included in these solutions are two streams generated by the ESOC Real Time Analysis Centre.
Standardization Activities
Participation in the IGS Real Time activities has stimulated ESOC’s involvement in the development of standards and formats for GNSS data and products. ESOC has been instrumental in the decision of the IGS to join the Radio Technical Commission for Maritime Services (RTCM), which is the primary standards setting organisation for real-time GNSS services. ESOC is now one of two agencies that represent the IGS at the RTCM meetings.
Work with the RTCM focuses on:
development of standards and formats for transmission of multi-constellation observations in real time (RTCM-MSM);
development of standards and formats for the transmission of real-time orbit and clock products (RTCM-SSR);
Further development of the RINEX standard for generation of multi-GNSS batch observation files.
Expertise and Areas of Activities
To comply with the main objectives of the NSO, the main pillars of expertise and areas of activities can be summarized as:
Precise orbit determination at centimeter-level accuracy for satellites in low-Earth orbits such as Earth observation missions, and satellites in medium-Earth orbits, typically GNSS satellites.
Development of state-of-the-art models and algorithms for high-precision orbit and clock determination, based on the capability to process all geodetic data types, namely GNSS, satellite laser ranging, Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), altimetry, and S-band tracking data.
Realization of Geodetic Reference Frame.
Operation of global distributed real-time sensor stations and networks, based on remote control of GNSS receivers.
The capability to operate complex navigation software infrastructure to generate operational products and services for a wide variety of applications.
Involvment in several international organized and coordinated activities. Besides being an IGS analysis center, ESOC’s NSO is also an analysis centre for the IDS and ILRS services.
Operational Facility
ESOC’s ESOC’s Navigation Facility (see FIGURE 3) provides a fully operational environment, compliant with ESA’s ECSS ground segment standards. The Navigation Facility consists of a control room including secure operational LAN (ESACERT against intruders from outside) with two physically separated computer and data centres for redundancy purposes and a globally distributed operational real time sensor station network (see FIGURE 4). An operational system availability of more than 99.9 percent on a 24/7 basis measured over the last 5 years (products delivered every 15 minutes) has been demonstrated.
Currently the sensor station network consists of 12 sites, but ESOC is extending the global network to at least 25 sites. Negotiations with new sites are currently ongoing or near completion. The objective is to deploy a homogeneous (all sites will have the same receiver and same antenna type) sensor station network by the third quarter of 2013. The deployment of new equipment on existing sites began in April 2012, and first results are very promising. The new type of geodetic quality GNSS receiver has been chosen, based on an internal selection process, and deployment is under way. Each receiver has 264 physical channels, is capable of multi-signal, multi-frequency and multi-constellation tracking and will be remotely controlled from the Navigation Facility at ESOC.
Software Packages
The NSO develops, maintains and operates a range of software packages and tools for high-precision orbit- and clock determination and prediction. The software capability also includes the estimation of station coordinates, Earth-orientation parameters, model parameters (radiation pressure, drag, and so on), ionosphere, troposphere, instrument biases, intersystem biases, ambiguities and antenna phase-centre variations based on state-of-the-art models and standards (for example, IERS, ITRF).
The main software packages used within the NSO are:
NAPEOS, which is the ESOC standard for high-precision navigation tasks. NAPEOS is used for almost all projects and is compliant with the highest navigation accuracy requirements, based on batch processing techniques with the capability to process different types of geodetic observations.
RETINA, the NSO’s real time software package for GNSS based precise navigation. This software is based on Kalman Filter techniques and has a closely coordinated interface to NAPEOS.
IONMON, processing GNSS data and producing ionosphere information and TEC map predictions.
In this context it is important to mention that ESA owns all the intellectual property rights to these software packages and that licences for operationally qualified software can be released on request to European companies, universities and R&D 0rganisations (currently only NAPEOS).
Summary and Outlook
The Navigation Support Office offers a combination of different capabilities, namely highest quality software, tools for real-time and batch processing ( the Office is the only analysis centre capable of processing three different geodetic techniques within a single software package), operation of own global GNSS sensor station network and demonstrated operational experience for mission support and provision of services. Operations are conducted in a controlled environment, fully in accordance with ESA safety and security standards.
The Navigation Support Office is ready for multi-frequency, multi-signal and multi constellation GNSS data processing. The Office is involved and strongly committed to support Galileo and EGNOS. In this context, the Office will soon become the consortium leader for the provision of the Galileo Geodetic Reference Frame.
Concerning the participation to international GNSS activities like IGS, ICG and GNSS standardisation aspects, the Navigation Support Office intends to continue its support for the foreseeable future.
In the area of LEO POD, the Navigation Support Office offers POD capability for all types of LEO satellites. For this reason, the Office intends to play a major role in the precise orbit determination activities for the European GMES Sentinel satellite missions.
Finally, the Navigation Support Office also intends to increase its capabilities related to navigation concepts for high-precision satellite formation flying and satellite constellations, via specific research and development activities. The aim is to maintain and expand its capabilities as a very attractive partner with cutting edge know-how and technology for the support of ESA activities and European industry.
Werner Enderle is the head of the Navigation Support Office at ESA\ESOC. Previously, he worked at the European GNSS Authority (GSA) as the Head of System Evolutions. He also worked for the European Commission, in charge of the procurement for the Galileo Ground Control Segment. He holds a doctoral degree in aerospace engineering from the Technical University of Berlin, Germany.
Co-authors: Rene Zandbergen, Tim Springer, and Loukis Agrotis.
A GPS Look-Alike to Compensate for Poor Indoor, Urban Availability
Editor’s Note: This article reproduces the acceptance speeches given by the winners of GPS World’s 2012 Leadership Awards, at the Leadership Dinner in Nashville in September. The Leadership Dinner was sponsored by Lockheed Martin and Deimos Space.
Remarks by Waldemar Kunysz
Senior Staff Engineer, winner in the Services category. He works on Wide-Area Positioning System (WAPS) design and implementation in the continental United States. He spent the previous 16 years with NovAtel, Inc., working on various research projects and novel antenna designs.
I am much honored to receive this award and recognition. It means a lot to me.
I would like to thank the people who made a difference in my career. Without them it would not be possible for me to be here.
First I am grateful to Dr. Maurice Meyer, former MIT professor. He taught me the black magic of antenna engineering. I am quite sure that his spirit guided me when I invented the GPS/GNSS Pinwheel antenna when working at NovAtel, for which I received six patents.
I also would like to thank Prof. Gerard Lachapelle and Dr. AJ Van Dierendock for teaching me GPS technology and Dr. Phillip Ward for providing very useful insight on the subject of interference. That knowledge saved me countless hours when troubleshooting some system-level issues while designing current and past GPS/GNSS products.
Currently I am working at NextNav LLC, developing technologies related to NextNav’s new terrestrial based Wide Area Positioning System (WAPS). Founded in 2008 and based in Sunnyvale, California, NextNav has designed a new positioning system that is being initially deployed across the United States, although we anticipate taking our technology to global markets in the future. In its short life, in addition to developing the technology necessary for a timing-based, high-accuracy terrestrial positioning system, NextNav has already established a network presence in 40 of the largest U.S. metropolitan areas. This system allows the reception of a GPS-like signal in the areas where satellite coverage is weak or non-existent, such as indoors or in dense urban developments, that is, downtowns, urban canyons, and so on. We already have completed a fully-deployed service capability in the San Francisco Bay area that enables consistently accurate indoor and outdoor positioning anywhere from San Francisco to San Jose, and we are growing our network footprint across the United States. We are also very excited to have developed a height system that has demonstrated consistent floor-level accuracy, a feature that is particularly valuable indoors.
As we know, all major terrestrial systems, such as Loran, Omega and Decca, have been shut down in the past several years. We have become very dependent on satellite-based services such as GPS and GLONASS without any terrestrially-based back-up. Any major solar storm in the future could be very disruptive to this service, so having a terrestrial-based system that is in sync with the satellite-based system will fill that void. And of course, a terrestrial system can be maintained and improved on a significantly shorter schedule, with significantly lower cost, than a space-based system. NextNav really provides an excellent complement to GPS.
The future looks very bright for the positioning service industry. In my opinion, by 2020 it will become another ubiquitously-available utility such as phone or power. I’d like to agree with my other awardee and predict that in 2020 we will be able to have a carrier-based positioning accuracy anywhere and anytime, available from any devices including handheld units. You will know where all your assets are and you won’t need to post a question to your wife: “Honey, did you see where my tie is?” Your personal digital assistant will locate it for you.
CYGNSS, Others Deliver Now and in Future for Global Weather Forecast
Editor’s Note: This article reproduces the acceptance speeches given by the winners of GPS World’s 2012 Leadership Awards, at the Leadership Dinner in Nashville in September. The Leadership Dinner was sponsored by Lockheed Martin and Deimos Space.
Martin Unwin, Surrey Satellite Technology Limited; Principal GNSS Engineer, winner in the Satellites category. He is a key member of the team that built the GIOVE-A satellite (recently retired) and is now working on the Galileo FOC satellites. He is also recognized for his work on space-borne receivers.
Headshot: Martin Unwin, Surrey Satellite Technology, winner in the Satellites category.
I feel privileged and honored to receive this award from GPS World, and I am truly sorry now that I chose this year not to attend the ION-GNSS conference to receive it!
With respect to the achievements in GIOVE-A and Galileo, I cannot claim this award on behalf of myself, but I will claim it on behalf of the people in Surrey Satellite Technology Limited (SSTL) who made the projects possible, and to those in the team here who have been working tirelessly to make the payloads and satellites happen. We are of course partnered with others in Europe that have been laboring equally hard, so it has been a true team effort.
With respect to the spaceborne GPS and GNSS activities, my achievements have only been possible thanks to the top-class staff we have in the receivers team, and thanks are also due to the support we have had from the rest of SSTL.
In the 20 years I have been in the company, Surrey Satellite Technology Ltd has grown from a small university-based department to a major player in the international space scene, and I am immensely proud to have been part of this story.
A Few Words for the Future
Whilst it cannot quite match the early heady days of GPS, I still think nevertheless we are entering an exciting time in the GNSS world. We have two operational systems, and within a few years, we will be seeing two more reaching operational capability. Dual- and even triple-frequency civil signals will soon become operationally available, and some very wide bandwidth signals will be sent down, in particular, by Galileo. There is bound to be a steep learning curve in understanding how to exploit these new signals, with a few crevasses to be negotiated during the climb. But these new signals are bound to lead to an expanded vista of increased accuracy and robustness, and undoubtedly some unexpected destinations.
Taking perhaps the highest perspective, spaceborne remote sensing is a good example that has surprising relevance to the rest of us still on the ground. In this case, GNSS satellites are used as radar sources, and all that is required on a low-Earth orbiting (LEO) satellite to change the world is a GNSS receiver. GPS radio-occultation measurements from low-Earth orbit are now already the third most important data source for our global weather forecasts, thanks to the like of the COSMIC and MetOp satellites.
Furthermore, a new constellation of satellites called CYGNSS has recently announced by NASA that will be using ocean-reflected GPS signals to probe inside hurricanes and typhoons, and for the first time will enable the sensing of the wide-scale ocean roughness, leading to improved global wind and wave knowledge. By adding to this spaceborne receiver the ability to accommodate signals from GLONASS, Galileo, and Compass, plus any other available GNSS-type signals, the number of measurements is instantly quadrupled, and a new capability in sensing the atmosphere, waves, and even ice and land is likely to be seen. Meteorologists already view GPS as an emerging utility for weather and climate sensing, but I think this new role for GNSS will be reinforced and expanded into yet another area where GNSS incontrovertibly, if indirectly, makes such a significant difference to our daily lives.
As with many other applications where GNSS has become important or even critical to our modern world, this is, at the same time, both a blessing and a matter for some caution.
Fully Operational System Modernizes for the Multi-GNSS World
Headshot: Vitaly Davydov and Sergey Revnivykh
By Vitaly Davydov and Sergey Revnivykh
Since December 2011, the GLONASS system has been fully operational, providing worldwide service with 100 percent global availability and acceptable accuracy for most users. The system is globally accepted by many users, and most leading manufacturers include GLONASS in their devices.
This fact became a reality due to the successful completion in December 2011 of the Russian Federal Mission Oriented Program dedicated to GLONASS restoration, under the under permanent supervision and control of the President of the Russian Federation and Russian Government, Vladimir Putin.
It may have seemed back in 2002 that very few people outside the GLONASS team believed in the success of the Program, when the constellation was composed of six operational satellites with only a 3-year lifetime. But now the GLONASS constellation consists of 24 modernized operational Glonass-M satellites and in-orbit spares. Further, the new generation GLONASS-K satellite flight tests have begun.
The GLONASS Program obtained significant support in May 2007 when the famous Decree of the President of the Russian Federation was issued. The President made commitments to sustain the GLONASS system and provide its open service free of charge and available for all users worldwide without any restrictions. At the same time, the President charged the Government to prepare and approve the new GLONASS Program for 2020. The new Federal Mission Oriented Program ,designated GLONASS maintenance, development and use for 2012–2020, was approved by the Government of the Russian Federation on March 3, 2012 with a dedicated article in the State Budget Law. That means that the President’s commitments are supported by real financial resources for the next decade, and the situation of the mid-1990s will never occur to GLONASS again.
The new Program has three major tasks:
To keep GLONASS in full operational mode.
To significantly improve GLONASS performance and service quality.
To provide conditions for worldwide use.
The tasks to make GLONASS an integral component of the global GNSS infrastructure, providing worldwide service for all users, are challenging. At the same time, the primary goal of GLONASS as a dual-use system is to serve national security interests.
What the Future Brings
GLONASS development in the near future is foreseen in a few key directions.
Space Segment. Modernization of the GLONASS core, called the Space Complex, undertakes the development of new spacecraft with enhanced performance. This means more stable on-board clocks, new code-division multiple-access (CDMA) signals, and intersatellite link for orbit, clock update, and range measurements. The GLONASS-K satellite will be the new generation spacecraft, applying advanced technologies.
The first-phase GLONASS-K satellite is already passing flight tests, transmitting new CDMA signal in L3 band in addition to the existing set of FDMA signals. The GLONASS-K of the second modernization phase will transmit the full set of new CDMA signals in L1, L2 and L3 bands.
At the same time, all new GLONASS satellites will continue transmitting the existing set of frequency-division multiple-access (FDMA) signals, providing backward compatibility with existing user equipment. Implementation of the CDMA signals in L5 and in L1 (1575.42 MHz) bands is also in line with the Signal Modernization Concept. This task is undergoing study to optimize the power and mass budget of future satellites and to consider benefits for users. Finally, new CDMA signals will provide better accuracy, better protection to interference and better service for users.
GLONASS modernization foresees extending the number of operational satellites in constellation available for users. Presently navigation message enables maximum 24 satellites for users. Activities in order to get more operation satellites available, assumes modernization of the existing FDMA almanac. New almanac of CDMA signals has no limitations.
Ground Segment. Ground-control segment modernization will produce a monitoring-station network extension to provide global coverage, extension of the uplink-station network to provide more frequent updates of orbit and clock, and system clock modernization to make the system time scale more stable and better synchronized with UTC.
The new geodesy reference PZ-90.11 is already coordinated with the International Terrestrial Reference Frame (ITRF) at the centimeter level and shall be introduced soon.
Augmentation. The System for Differential Correction and Monitoring (SDCM) space-based augmentation system is dedicated to improving navigation services, providing integrity data and better accuracy for users. As a first phase, the service area of SDCM is over the Russian territory. For SBAS signal re-transmission, the three GEO communication satellites of the Luch system are equipped with navigation transponders. The first Luch-5A is already in orbit. The other two are scheduled for launch. Eventually the SDCM system will provide a global navigation service, transmitting precise orbit and clock data to users and introducing precise-point positioning (PPP) technique.
Performance Improvements. The GLONASS modernization plan foresees step-by-step performance improvement of all system components. By 2020, the GLONASS system in stand-alone mode will provide sub-meter accuracy for users with an open signal. Augmented by SBAS, the GLONASS system will provide user positioning accuracy at the decimeter level and better.
In the coming Multi-GNSS world, the GLONASS system must be one of the key components to benefit all users with reliable and accurate navigation, positioning, and timing services. To reach that goal, the international cooperation between system providers with feedback from all group of users is a mandatory condition. All global and regional navigation satellite systems must be compatible and interoperable. The International Committee on GNSS, established according to UN recommendation, plays a significant role for international cooperation aimed at achieving synergy in the navigation environment.
2013 is very important for GLONASS to demonstrate stability with improvement for all users around the world. All the necessary resources to achieve this are available, based on the long-term Federal Mission Oriented Program supported by the President and the Government of the Russian Federation.
Vitaly Davydov is the deputy head of the Federal Space Agency, Coordinator of the Program for GLONASS Sustainment, Development, and Use. He graduated from the Dzerzhinsky Military Academy and from the Russian Presidential Academy of National Economy and Public Administration with a Master‘s degree in Public and Municipal Administration. From 1997 to 2004 Vitaly Davydov supported the Russian Federation Security Council’s Office. Prior to that from 1975 to 1997 he occupied various positions in Russian Department of Defense’s Space Forces.
Sergey Revnivykh is deputy director general of the Central Research Institute of Machine Building, leading institute of Federal Space Agency, Head of PNT (Positioning, Navigation and Time) Analysis and Information Center. He is a member of the management of the Federal GLONASS Program. He received his Ph.D. degree from the Moscow Aviation Institute.
GPS Directorate: Receivers Will Operate in Environments Impossible Today
By Col. Bernie Gruber
Headshot: Col. Bernie Gruber
I believe the future of global navigation satellite systems (GNSS) and particularly GPS will only be limited by our ingenuity and imagination. In terms of economic benefit, GPS contributes $60 billion to our economy, and that’s no stretch considering the positive and real advantages GPS affords us every day through fuel savings, transportation optimization, banking transactions, recreational activities, and certainly the defense of our great nation.
GPS consists of three segments — space, ground and user equipment — all contributing synchronistically to provide the world positioning, navigation, and timing (PNT). Having joined the GPS program office (for the first time) in 1992, I was privileged to lead the very first Foreign Military Sales contracts and the development of the Selective Availability Anti-Spoofing module (SAASM) — both focused within the realm of user equipment. As program director of GPS reflecting back on the monumental change of the past 20 years, I am encouraged and look forward to seeing the fruition of the projects and plans we have already set in motion for the next 20. This is why:
Space Segment. The launch and handover of the third GPS IIF satellite on October 4 proves once again our commitment to mission success. We have exceeded our published worldwide accuracy standard since 1993, and the NavStar GPS constellation remains robust with 31 satellites currently available.
In regards to the satellite systems, next-generation Block IIF and III satellites are in various states of test, integration, or production in an effort to improve the average user range error (URE) from 0.9 meters, achieved and maintained for the last 3 years, to a root-mean-squared URE of 0.5 meters by 2016. Along with increased civil and military signals, I also envision digital waveform generation (that is, the ability to change on-orbit signals in space via software) as an integral part of our architecture. Digital waveform generation coupled with an augmentation of the GPS III constellation for affordability and resiliency will pave our way to the future.
Ground Segment. Along with a host of additional satellite capabilities and signals, we will correspondingly modernize our ground segment. Our Next-Generation Operational Control System (OCX) is designed to command and control our modernized secondary civil signal L2C, safety-of-life signal L5, and the internationally compatible signal L1C. In fact, users such as John Deere and NavCom are already accessing the currently broadcast L1 C/A and L2C (with a default code) for dual-frequency ionospheric correction to improve upon accuracy. As the modernized signals become operational, users will see faster signal acquisition, enhanced reliability, and a greater operating range. The information assurance, expandability, and service-oriented architecture will afford users and operators with security and information they simply don’t have today.
User Segment. All that said, I am thrilled to look at the future of user equipment. We need to take advantage of the use of civil GPS. Apple and Android have shown the way to interface with and use applications, displays, and packaging; Google Map overlays, smart phone apps, time-to-first-fix augmentations from cell towers, and multi-GNSS international coverage are already in use, with the growth of apps, users will only get smarter and more sophisticated in their GPS expectations.
To that end, the Air Force is augmenting its pilots with digital maps and starting to integrate GPS with the digi-maps beginning with the C-130J. The Army is paving the way with an app store for military use and beginning to integrate GPS with its equipment, such as the use of a GPS integrated wind app for calibrating bullet trajectories.
Security, authentication, integrity, and the ability to operate in almost any environment is vital to our warfighters. The Department of Defense is posturing to operate in an anti-access area denial (A2AD) environment. Make no mistake; the list of potential adversaries also includes a list of known attacks on GPS — along with use of GPS and other GNSS systems against us. For that purpose, the modernized GPS is working on better and improved items like key management, M-Code power and cryptography, and Blue Force Electronic Attack (BFEA). In this area too, I see the commercial market burgeoning with new ideas to protect the calculation of GPS PNT solutions.
In the selective-availability anti-spoofing module, we introduced positive control and resiliency to the military GPS receivers. Now with M-Code we are taking it one step further. M-code will leverage the National Security Agency (NSA) Key Management Infrastructure and augment it with more tools to ensure only authorized users have access to M-Code. This provides greater protection from spoofing, ensures that keys are readily available to the United States and her Coalition partners, and that security cost drives for our user equipment are minimized.
With more signal power, almost every aspect of GPS is better. While the 6–10 dB of additional power in GPS III will not in itself defeat known threats, more power complements anti-jam techniques as well as improves operation under foliage and in the presence of pervasive unintentional interference. We’re going to see receivers that operate in navwar environments that would be impossible today. Similarly, I see us having the flexibility to operate with other GNSS systems in benign environments, but the ability to also operate in hostile or contested environments.
Blue Force Electronic Attack was always a principle driver for GPS modernization. It is embodied in the White House Directives and Title 10 U.S.C [Title 10 of the United States Code outlines the role of armed forces in the U.S. Code, a compilation and codification of the general and permanent federal laws of the United States — Ed.] Today’s Block II systems do not have enough spectral separation for effective BFEA. As M-Code becomes readily available, along with the additional filtering available in military GPS user equipment (MGUE), we are providing Joint Task Force Commanders with options to deny GPS; options that they don’t have today.
The future of GPS is bright indeed! From the originators of GPS to present day men and women who work tirelessly to deliver and operate it, we are all striving to improve and enhance this magnificent capability. The economic benefits of a system that, in reality, pays for itself guarantees the world’s desire to see improvements and growth in the overall GPS system. The Air Force is a proud steward of the GPS system, but it is our collective job to proliferate new ideas to use it and secure it.
Colonel Bernie J. Gruber is director, Global Positioning Systems (GPS) Directorate, Space and Missile Systems Center, Air Force Space Command, Los Angeles Air Force Base, California. He is responsible for a multiservice, multinational systems directorate which conducts development, acquisition, fielding and sustainment of all GPS space segment, satellite command and control (ground) and military user equipment. The $32 billion GPS program, with a $1 billion annual budget, maintains the largest satellite constellation and the largest avionics integration and installation program in the Department of Defense. He has served in key positions at Major Command, Air Staff, Joint Staff and Defense Agency levels. Prior to assuming his current position, Colonel Gruber was Chief, Space Superiority and Global Integrated Intelligence, Surveillance and Reconnaissance Division, Directorate of Programs, Deputy Chief of Staff, Strategic Plans and Programs, Headquarters, United States Air Force, Washington, D.C.
Editor’s Note: This article reproduces the acceptance speeches given by the winners of GPS World’s 2012 Leadership Awards, at the Leadership Dinner in Nashville in September. The Leadership Dinner was sponsored by Lockheed Martin and Deimos Space.
Remarks by Todd Humphreys, Radionavigation Laboratory (director), University of Texas at Austin (assistant professor), winner in the Signals category. He is the leader of several seminal studies on spoofing and jamming, and he testified this summer before Congress on the subject.
It’s a genuine honor to receive this award. I’d like to thank Alan Cameron and all the contributors to GPS World. GPS World plays an essential role in building our GNSS community and keeping it together, providing GNSS news, instruction, and, indispensably, gossip!
I’d also like to thank my students at the University of Texas Radionavigation Lab. Much of the credit for this award goes to them.
The futurist Ray Kurzweil spoke at a conference I attended back in 2001. Maybe some of you have heard of Ray. He’s regarded variously as a prophet, or a crackpot. He’s taking hundreds of vitamins every day to keep himself alive until the singularity arrives, at which point he’ll download himself onto a robot and live forever, or at least he’ll have his head cryogenically frozen so that he can be downloaded and live forever later on.
In that 2001 talk, Ray made some bold predictions. One, in particular, I remember well. “Within the decade,” Ray assured us, “we’ll all be wearing special contact lenses that give us a permanant Internet feed directly to our eyeballs.”
Nonsense, I thought, and indeed it was nonsense. Here we are in 2012 and no such contact lenses exist, nevermind their being in widespread use.
I resolved back then that if I were ever called on to peer into the future and tell what I see, as Alan has asked me to do tonight, I’d be more modest about it.
So tonight I’m going to make a modest prediction, and only one of them. I predict that by the GPS World dinner in 2020, carrier-phase differential GNSS, or, if you prefer an adjective for what should be a noun, Real-Time Kinematic, will be cheap and pervasive. We’ll have it on our cell phones and our tablets. There will be app families devoted to decimeter- and centimeter-level accuracy. The consequences will be fantastic. And this will be enormously disruptive to the current precision navigation industry. This will be the commoditization of centimeter-level GNSS.
Now you may very well object to this prediction. You might point out that integer ambiguities will be difficult to resolve in the face of the near-field effects around and poor placement of the GNSS antenna in handheld units. You might also argue that the increased power requirements of carrier-phase techniques will be a dealbreaker for mobile devices. That’s all fine. I agree that those are hard problems. My students and I are looking into them, trying to overcome them.
But please don’t make as one of your objections the one that I’ve heard so many times: “Why would anyone ever want centimeter-accurate positioning in their cell phone?” Because I’ll object that your objection lacks imagination.
To see one example of what could be done with commoditized centimeter-accurate GNSS, I invite you all to a presentation by my students Daniel Shepard, Ken Pesyna, and Jahshan Bhatti tomorrow in the F5 Session (Millimeter-accurate Augmented Reality Enabled by Carrier-Phase Differential GPS). They’ll show off a crude box that we’ve built, through which, if you peer, you can see a sandcastle that’s not really there. And you can walk around the sandcastle and see it from all sides with centimeter accuracy.
Imagine when this technology is in our tablets! Or, better yet, when it’s in our glasses — or, I suppose, our contact lenses. Not that I’m making any predictions about contact lenses.
[Ed. For a short video demonstration of the RTK-enabled augmented reality box built by Todd Humphreys’ students, visit this site.]
Some of you have been asking questions, and while it is generally our business to provide answers, in this case I simply show these questions back to you, for instructive purposes.
They come from the 2012 State of the Industry Survey, reported in the September issue. In that survey, we posed one question whose results were not reflected in that report. It was “What questions do you think it would be interesting and illuminating to ask in the 2013 State of the Industry Survey?”
Herewith those questioning answers — er, those answering questions:
What effect will the aging satellite system have, and what are you doing to plan for an alternative?
Which industry is the most powerful to impose its technology standard? For example, it seems that any technology not compatible with mobiles or tablets is not alive anymore.
What is the estimated financial impact that GNSS have, and how would it affect your life if we didn’t have them?
With the technology of the GNSS equipment constantly improving, how important is it that the end user be a licensed professional?
The prices of Chinese products — are they directly affecting your sales, or are your customers taking these low prices as a starting point for negotiation?
Should precision and accuracy be government regulated?
What will be the next game changer for positioning? Will it be all encompassing like GPS? Or will there be multiple positioning options depending on your need? (indoors, urban corridor, dense veg., accuracy needs, and so on).
How can the cost of modern survey equipment be subsidized for developing countries?
How long will multi-chip solutions maintain dominance compared to separated solutions where technological development and cost reduction is even faster?
What alternative tracking methodology will replace GPS/GNSS as the most common?
What are the cost and practical barriers to innovating new consumer and business products? Are you willing to throw away existing products to distribute new products?
How accurate is good enough?
Is replacement of staff with technical skills a concern?
Should the recent demonstration of commandeer-via-spoofing have been so widely publicized — or should that development have been classified?
Have your customers expressed concern about GPS tracking and their privacy?
What will it take to get RTK GNSS receiver manufacturers to standardize on one correction data format? What portion of revenues is invested in GNSS-related research and development at your company?
What is the status of the National PNT Architecture jointly developed by the US DoD and DOT? Is it viable, or is it dead?
The FCC director was on drugs the day they granted LightSquared bandwith — true or false?
What would be the effect of a 1-hour, 1-day, or 1-week disruption in GPS be on your product? What is your backup system?
What will be the long-term consequences of the CBOC patent issue? [Note that while a story on this page give a short-term answer, long-term consequences of intellectual property concepts are far from settled. — Ed.]
Is there still room for a LightSquared type technology in the current broadband and spectrum governance environment?
What kind of disaster will be required to get the U.S. government off the dime on an uncorrelated-failure alternative PNT system?
Are commercial manufacturers considering offering more flexibility in their receiver designs (open-source GNSS). Open hardware is an interesting trend.
What’s next after GPS III?
Will the COMPASS system gain general acceptance in 2013-2014?
Tell us more about the future.
[That last was my favorite question, one after my own heart. For any other questions you may have, or any answers for that matter, or if you have even a clue, please write to me at [email protected]. I’m listening. — Ed.]
An experimental GPS receiver, built by Surrey Satellite Technology Limited (SSTL), has successfully achieved a GPS position fix at 23,300 kilometers altitude – the first position fix above the GPS constellation on a civilian satellite. The SGR-GEO receiver is collecting data that could help SSTL to develop a receiver to navigate spacecraft in geostationary orbit (GEO) or even in deep space.
GPS is routinely used on Low Earth Orbit (LEO) satellites to provide the orbital position and offer a source of time to the satellite. Spacecraft in orbits higher than the 20,000 km of the GPS constellation, however, can only receive a few of the signals that “spill over” from the far side of the Earth, meaning that the signals are much weaker and a position fix cannot always be secured.
With the support of the European Space Agency (ESA) and the ARTES 4 program, SSTL included the SGR-GEO receiver on the GIOVE-A satellite to prove that a receiver could achieve a position fix from a higher orbit. The SGR-GEO is adapted from SSTL’s SGR range of receivers and incorporates a high-gain antenna and a precise oven-controlled clock. It will demonstrate special algorithms to allow reception of weak signals and an orbit estimator intended to allow a near continuous position fix throughout orbit.
“The results from the SGR-GEO receiver are really encouraging,” said Martin Unwin, principal GNSS engineer at SSTL. “We’re getting higher signal strengths than anticipated and also acquiring side lobes from the GPS transmit antennas, which improves the availability of the usable signals for navigation. With the success of the SGR-GEO receiver, GPS, in combination with Galileo and GLONASS, could soon be helping navigate spacecraft much further away from Earth.”
The experimental GPS receiver onboard GIOVE-A has been inactive for six years while the satellite has been used for its primary purpose of transmitting prototype Galileo signals. GIOVE-A’s retirement in June 2012 has allowed the commissioning of the experiment and is now providing valuable data to SSTL and ESA in support of the future use of spaceborne GNSS receivers at GEO altitudes. Engineers at SSTL will continue operations, testing out, tuning and improving the receiver software onboard GIOVE-A to achieve the best possible performance.
earthmine, Inc., announced today that it is has entered into an agreement to be acquired by Nokia. earthmine, based in Berkeley, California, is a privately owned company that develops a powerful end-to-end 3D street level imaging solution — from collection hardware to processing workflows, cloud hosting and client software.
The earthmine team is expected to join the Nokia location and commerce business, and Berkeley will become a key site for the development of 3D reality capture technology. “We are very excited to be joining Nokia, a company with a huge presence and vision in mapping,” said John Ristevski, co-CEO of earthmine Inc. “We could not hope for a better place to fulfill and accelerate our mission of indexing the world in 3D.”
The transaction is expected to close by the end of 2012. The terms of the transaction are confidential.
earthmine, Inc., provides 3D street-level imagery, delivering an end-to-end solution including 3D mobile mapping systems, automated data-processing pipelines, cloud-based hosting services and server software, desktop software, client-side developer tools, and direct integration with GIS software. earthmine technology is being used in local search, mobile, mapping, GIS, safety, and security markets in the United States, Mexico, Brazil, Canada, France, Australia, Japan, Malaysia, Singapore, Korea, Saudi Arabia, as well as other countries around the world.
GTX Corp, which makes customizable, patented two-way GPS solutions, has announced the approval of a custom designed GPS tracking device for use on the cargo airlines AirNet and Cargolux. The custom configured device will be made available as an add-on service to customers of MNX, a provider of expedited transportation and logistics services, to provide a new level of visibility and control for high value and mission critical shipments.
“We have been working diligently with AirNet and Cargolux to gain the necessary approvals to bring this one-of-a-kind offering to market. We are very pleased to see this day finally come to fruition,” said Patrick Bertagna, GTX Corp cChairman and CEO. “Over the next few weeks we will work closely with the MNX team to formulate a domestic and international deployment strategy to introduce this offering to MNX customers around the world.”
Designed for customers that ship high value, time or temperature sensitive materials, the technology is well-suited for customers in the life sciences industry. The GPS solution will bring extra security to sensitive shipments, including the transportation of items such as organs, blood, tissue, medications, clinical trial samples and medical devices.
“The GTX Corp tracking platform gives us the ability to better identify and resolve any unforeseen challenges throughout the entire transport and gives our customers added confidence and peace of mind that their shipment is secure at every step,” said Scott Cannon, MNX CEO. “By providing our clients with real-time tracking of their shipments, MNX will offer an unmatched layer of service, security, temperature integrity and reliability.”
The GPS device transmits the latitude and longitude, speed, bearing, altitude and temperature of the plane or vehicle carrying the shipment. The device and GTX platform also provide an easy-to-use customer interface with live shipment tracking and geo-fencing capabilities, allowing customers to know exactly when their mission critical shipments depart and arrive in key destinations. The GTX device is small and light weight (comparable to the size of a standard garage door opener), making it easy to insert in even the smallest packages.
“We realize the capability to track valuable shipments with such detail is especially important to the life sciences industry, especially as this industry continues to expand so rapidly,” said Bertagna.
AirNet, a leading domestic specialty cargo airline specializing in life sciences transportation, and Cargolux, one of the leading scheduled all-cargo airlines, were among the first airlines to conduct a thorough testing process to certify the GTX device, while MNX and GTX continue collaborating to expand the use of the offering to other partner airlines.
