The National Coordination Office for Spaced-Based PNT is the permanent staff of the National Executive Committee for Space-Based Positioning, Navigation, and Timing. It is the central node within the government for GPS-related policy matters.
Brecht-Clark is a Senior Executive Service (SES) official from the Department of Transportation’s (DOT) Research and Innovative Technology Administration (RITA). She is recognized in the areas of research and policy development related to transportation safety and security. She has more than 30 years of experience with federal and state government offices as well as industry firms.
In 2011-2012, Brecht-Clark served for 19 months as the Counselor for Transportation with the U.S. Embassy in Kabul, Afghanistan. Appointed by the Secretary of Transportation, she managed a team of professionals from across DOT, working to assist the government of Afghanistan in developing their governance capacity over transportation assets and responsibilities. Her team assisted the Afghan government in the design and approval of both a civil aviation authority and a railroad authority.
Russo served as the director from January 19, 2010, to December 14, 2012. During that time, he was also an SES official from the DOT’s RITA. Russo also served as deputy director of the National Coordination Office from 2007 to 2009. During that time, he was an active duty Air Force Colonel representing the Department of Defense.
The Lockheed Martin team developing the U.S. Air Force’s next generation Global Position System III satellites has completed a key flight software milestone validating the software’s ability to provide reliable and effective command and control for the GPS III satellites planned for launch into orbit.
The GPS III program will affordably replace aging GPS satellites, while improving capability to meet the evolving demands of military, commercial and civilian users. GPS III satellites will deliver better accuracy and improved anti-jamming power while enhancing the spacecraft’s design life and adding a new civil signal designed to be interoperable with international global navigation satellite systems.
The milestone, known as Software Item Qualification Testing (SIQT), was completed for the satellite’s spacecraft bus flight software, which is critical to controlling the spacecraft on orbit and monitoring the health and safety of the satellite’s subsystems. SIQT included 131 individual test events and represented the culmination of a rigorous software engineering risk reduction and development phase. The software will next be integrated and tested on the first GPS III satellite, which is on schedule for launch availability in 2014.
“Completion of this flight software milestone demonstrates our continued positive program momentum and is another step forward in reducing risk up front to facilitate long term affordability,” said Lt. Col. William ‘Todd’ Caldwell, the U.S. Air Force’s GPS III program manager. “In this challenging budget environment, the entire government and industry team is focused on delivering the critical GPS III satellites affordably and efficiently for users worldwide.”
To further reduce risk, the flight software has already been integrated and tested on the program’s satellite prototype, known as the GPS III Non-Flight Satellite Testbed (GNST).
“Delivering fully qualified flight software this early in program development demonstrates the rigor of our GPS III software development processes,” said Keoki Jackson, vice president of Lockheed Martin’s Navigation Systems mission area. “Through up-front investments in high-fidelity, flight equivalent hardware and software testbeds, our team successfully executed on schedule to develop and qualify the flight software critical to the success of the GPS III program.”
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.
The GPS III team is led by the Global Positioning Systems Directorate at the U.S. Air Force Space and Missile Systems Center. Lockheed Martin is the GPS III prime contractor with teammates ITT Exelis, General Dynamics, Infinity Systems Engineering, Honeywell, ATK and other subcontractors. Air Force Space Command’s 2nd Space Operations Squadron (2SOPS), based at Schriever Air Force Base, Colorado, manages and operates the GPS constellation for both civil and military users.
Symmetricom, Inc. today announced two new capabilities for its SSU 2000 Synchronization Supply Unit: a GLONASS timing reference that uses signals from the satellite navigation system operated by the Russian Aerospace Defense Forces, and Synchronous Ethernet (SyncE), an ITU-T synchronization standard that delivers frequency synchronization over the Ethernet physical layer.
This enhanced version of the SSU 2000 will be the first in a series of forthcoming Symmetricom products that include GLONASS capabilities.
Available as an integrated card for the Symmetricom SSU 2000, the GLONASS referencing feature will allow customers to support both GPS and GLONASS simultaneously, providing added protection should signals from one navigation system become unavailable. GPS has long served as the primary reference signal for timing and synchronization in telecommunications and other networks. Operators in some regions prefer to use the GLONASS system, either as the primary time reference or in conjunction with GPS signals. Symmetricom has enhanced the SSU 2000 satellite receiver functionality to meet this demand.
“GLONASS signals have become an important primary reference for timing and synchronization systems,” said Laura Finkelstein, vice president of product management for Symmetricom. “The SSU 2000 is well-established as the synchronization platform for communication service providers globally. The integrated capability to simultaneously support both GPS and GLONASS provides our customers another way to improve the reliability of their network.”
Timing and synchronization are a focal point technology in Ethernet and mobile carrier networks today. Synchronous Ethernet allows frequency signals to transfer at the physical layer over Ethernet, helping improve network reliability by offering synchronization services to Carrier Ethernet networks. Using SyncE to complement IEEE 1588 Precision Time Protocol (PTP) can enhance PTP services being delivered to mobile base stations deployed in radio access networks. The new SSU 2000 capability puts SyncE and PTP on the same output port, thus providing an ideal synchronization solution for the evolution of mobile networks as they extend coverage and increase capacity.
Designed in a NEBS-compliant package, the SSU 2000 integrates intelligent functional modules into a flexible, fully redundant system. This enables telecom network operators to seamlessly satisfy current and future requirements for generating and distributing superior synchronization signals for advanced network services.
The SSU 2000 has been deployed in more than 125 countries as a timing and synchronization distribution system for communications service providers.
On January 31, Hemisphere GNSS Inc., a subsidiary of Beijing UniStrong Science & Technology Co. Ltd., purchased the Precision Products business and related GNSS technology and intellectual property from Hemisphere GPS Inc. for $15 million US. In a related press release, Hemisphere GPS Inc. has announced the intention to change its company name to AgJunction.
As part of the transaction, Hemisphere GNSS acquired all of the high-precision GNSS product lines, all related intellectual property rights and the Hemisphere GPS trademarks and brands. The Precision Products segment generated revenues of approximately $13.3 million in 2012 serving marine, land survey, construction, mapping, and OEM segments.
Hemisphere GNSS will operate its business headquarters out of Scottsdale, Arizona, and will maintain its operations in Calgary, Alberta, Canada.
Phil Gabriel has been appointed president of Hemisphere GNSS Inc. and will also serve as a board member. Gabriel has more than 15 years of experience with Hemisphere GPS, serving for the past six years as the vice president and general manager of the Precision Products business. “We are truly excited about our future growth prospects as a fully focused GNSS products and technology provider,” Gabriel said. “I would like to assure all our global distribution partners, suppliers and customers that it remains business as usual as we take our first steps forward with the strong backing of UniStrong.”
With this acquisition, UniStrong is expanding its capabilities in the high-precision GNSS business and also expects to promote commercial applications of China’s BeiDou Navigation System. UniStrong is listed on the Shenzhen Stock Exchange under ticker 002383.
Business analysts have reported in China that this is the first acquisition of an internationally renowned enterprise initiated by a domestic enterprise in China’s satellite navigation industry and represents an important milestone in the development of the industry. “The acquisition will create an international route enabling UniStrong to expand its global business outlook, enhance our ability to attract international talent, and lay the foundation for international growth and profitability,” stated Xingping Guo, president and CEO of UniStrong.
As part of the agreement, Hemisphere GNSS and AgJunction have formed a strategic alliance and a collaborative business relationship covering supply chain management, customer support, technology development and cross-licensing. “Having already established a relationship with UniStrong as one of our resellers made our new alliance a win-win for both parties,” said Rick Heiniger, president and CEO of AgJunction. “I am very pleased to be working together in this close technology-sharing relationship.”
Hemisphere GNSS’s newly appointed board of directors brings additional GNSS industry experience to the company. The board is chaired by Jonathan W. Ladd, former president and CEO of NovAtel Inc. Also joining the board is Werner Gartner, former executive vice president and CFO of NovAtel Inc.
“Hemisphere’s talented team will leverage its core GNSS capabilities and product marketing knowledge with UniStrong’s high quality, low cost GNSS product design and development resources,” said Ladd. “Hemisphere’s existing and future customers and partners will most certainly benefit from the resulting rapid, cost-effective product innovation across multiple product lines.”
Beijing UniStrong is focused on GNSS industry, with R&D, production, engineering, sales and service facilities. Its technical solutions and products cover GPS/GLONASS/COMPASS receivers, multi-system navigation and positioning, high-accuracy surveying, GNSS data post-processing, and system integration.
The re-branding of Hemisphere GPS as AgJunction is an integral part of the strategic re-focusing of the company’s resources on precision agriculture, and part of the restructuring initiated in September 2012. The company maintains ownership of its key patents and leading agricultural brands including AgJunction, Outback Guidance, and Satloc.
LabSat 2 now has the ability to record and replay satellite signals from the rapidly expanding Chinese navigation system, BeiDou. LabSat 2 users can now record and replay any combination of two channels from the three available constellations, GPS, GLONASS, and Beidou.
Existing LabSat 2 users can download the latest firmware (v2.0.0) and PC software (v2.6.14) to add this functionality with no cost.
There is a growing trend to include multi-constellation capability into new satellite navigation receivers, giving the end user better coverage in urban canyons, and overall improved positional accuracy, LabSat said.
There are now 14 operational Beidou satellites, and we have recorded a number of different files from Europe and China containing between 6 and 8 satellites. These scenarios are now included on the hard disk which is shipped with a LabSat 2, which can also be shipped out to existing customers on request.
The new firmware and software is now available from the Support section of the LabSat website. Follow the upgrade firmware instructions in the manual to upgrade your LabSat 2. For more information contact our LabSat Product Manager, Mark Sampson, [email protected].
BeiDou ICD: Signal Specs Are Free At Last; First Demonstration of Galileo-Only Positioning (By Peter Steigenberger, Urs Hugentobler, and Oliver Montenbruck)
BeiDou ICD: Signal Specs Are Free At Last
The interface control document (ICD) describing the details of the BeiDou B1I open service signal on 1561.098 MHz was released December 27 at a news conference held in Beijing by the Chinese State Council Information Office. The ICD includes details of the navigation message, parameters of the satellite almanacs, and ephemerides that did not appear an earlier, incomplete version of the ICD released at the end of 2011.
Beidou
An English version is available for download courtesy of the University of New Brunswick. The ICD specifies the relations of the signal in space interface between BeiDou Navigation Satellite System and users’ terminal receivers. It is the essential technical document to develop and make receivers and chips.
Anyone who has questions about the ICD is invited to submit them to [email protected].
The document, BeiDou Navigation Satellite System Signal In Space Interface Control Document — Open Service Signal B1I (Version 1.0), includes a system introduction, signal standards and navigation message, which defines the related contents of the open-service signal B1I between the BeiDou Navigation Satellite System and users’ terminals.
In a previous presentation given at the Seventh Meeting of the International Committee on Global Navigation Satellite Systems (ICG) in November, 2012, BeiDou officials stated that by 2020 there will be five GEO and 30 non-GEO satellites. The number of IGSO and MEO satellites was not specified, but previous presentations have said three IGSOs and 27 MEOs. These numbers are also stated in the official ICD.
“The GEO satellites are operating in orbit at an altitude of 35,786 kilometers and positioned at 58.75°E, 80°E, 110.5°E, 140°E and 160°E respectively. The MEO satellites are operating in orbit at an altitude of 21,528 kilometers and an inclination of 55° to the equatorial plane. The IGSO satellites are operating in orbit at an altitude of 35,786 kilometers and an inclination of 55° to the equatorial plane.”
The China Satellite Navigation Office presented a new official logo for the BeiDou system, with a yin/yang symbol representing Chinese culture, dark and light blue for space and Earth, and the Big Dipper constellation, symbolizing a long tradition of Chinese navigation since ancient times.
A spokesperson said the English name for China’s GNSS will be BeiDou Navigation Satellite System, abbreviated as BDS. The name Compass, which first designated the prototype regional system and has been employed in conjunction with the name BeiDou, will apparently now be discontinued.
Other salient details from the ICD include:
Signal Structure. “The B1 signal is the sum of channel I and Q which are in phase quadrature of each other. The ranging code and NAV message are modulated on carrier. The signal is composed of the carrier frequency, ranging code and NAV message.
“The B1 signal is expressed as follows:
S j (t) = A I C I j (t) D I j (t) cos (2 π f0 t φ j) + A Q C Q j (t) D Q j (t) sin (2 π f0 t + φ j)
where superscript j is the satellite number; subscript I equals channel I; subscript Q is channel Q; A is the signal amplitude; C the ranging code; D the data modulated on ranging code; f0 represents the carrier frequency; and φ the carrier initial phase.”
The nominal frequency of the B1I signal is 1561.098 MHz.
As is the norm with most other GNSSs, BeiDou’s transmitted signal is modulated by quadrature phase shift keying (QPSK). The transmitted signal will be right-handed circularly polarized (RHCP), and its multiplexing mode is code-division multiple-access (CDMA).
User-Received Signal Power Level. “The minimum user-received signal power level is specified to be -163 dBW for B1I, which is measured at the output of a 0 dB RHCP receiving antenna (located near ground), when the satellite’s elevation angle is higher than 5 degree.”
Bandwidth and Suppression. “Bandwidth (1 dB): 4.092 MHz (centered at carrier frequency of B1I); Bandwidth (3 dB): 16 MHz (centered at carrier frequency of B1I). Out-band suppression: no less than 15 dB on f0±30 MHz, where f0 is the carrier frequency of B1I signal.”
Ranging Code on B1I. “The chip rate of the B1I ranging code is 2.046 Mcps, and the length is 2,046 chips. The B1I ranging code (hereinafter referred to as CB1I) is a balanced Gold code truncated with the last one chip. The Gold code is generated by means of Modulo-2 addition of G1 and G2 sequences which are respectively derived from two 11-bit linear shift registers.”
NAV Message. “NAV messages are formatted in D1 and D2 based on their rate and structure. The rate of D1 NAV message which is modulated with 1 kbps secondary code is 50 bps. D1 NAV message contains basic NAV information (fundamental NAV information of the broadcasting satellites, almanac information for all satellites as well as the time offsets from other systems); while D2 NAV message contains basic NAV and augmentation service information (the BDS integrity, differential and ionospheric grid information) and its rate is 500 bps.
“The NAV message broadcast by MEO/IGSO and GEO satellites is D1 and D2 respectively.” The adjacent table from the BeiDou ICD gives information on nav message contents.
First Demonstration of Galileo-Only Positioning
By Peter Steigenberger, Urs Hugentobler, and Oliver Montenbruck
The European satellite navigation system, Galileo, is currently in its in-orbit validation (IOV) phase with a constellation of four satellites. The satellites, launched in pairs on October 21, 2011, and October 12, 2012, are representative of the full 30-satellite constellation. The IOV satellites will demonstrate that the satellites and the ground segment meet the system’s requirements and will validate the system’s design before completion of the rest of the constellation.
The IOV satellites have already started transmitting signals, and short periods of four-satellite visibility have allowed us to demonstrate, for the first time, absolute and relative positioning using measurements from Galileo operational satellites only. This follows the positioning demonstration last year with the signals from the Galileo IOV Element (GIOVE) test satellites and the first two IOV satellites. As in that earlier work, external orbit and clock information is necessary, since the IOV satellites were not transmitting valid navigation messages at the time of our study.
Three Javad GNSS Triumph-VS receivers with external antennas were set up at Technische Universität München (TUM) in Munich, Germany. The reference station TUME is equipped with a Javad GNSS RingAntG3T choke-ring antenna whereas the stations TUMW and TUMO are equipped with Javad GNSS GrAntG3T antennas. Unfortunately, all antennas are mounted near metal surfaces introducing pronounced multipath effects. The resulting baseline lengths are approximately 19.4 meters for TUME-TUMW and 101.7 meters for TUME-TUMO. Galileo satellite orbit and clock information was determined from stations of the Cooperative Network for GNSS Observation (CONGO) and the Multi-GNSS Experiment (MGEX) of the International GNSS Service (IGS). For GPS satellites, the rapid products of the Center for Orbit Determination in Europe (CODE) were used. All computations were performed with a modified version of the Bernese GPS Software 5.0.
Figure 1. Single-point positioning results for the TUME reference station based on E1/E5a dual-frequency pseudorange measurements of the four Galileo IOV satellites. The standard deviations in the north, east, and up directions are given. Note the different scale of the north component.
At a cutoff angle of 10 degrees, the four IOV satellites were jointly visible from TUM on January 6, 2013, for about two hours – from 04:16 to 06:09 UTC. Using an ionosphere-free dual-frequency linear combination of pseudorange measurements on the Galileo E1 and E5a frequencies, the position of the TUME reference station could be determined with a 3D position error of less than 1.5 meters (see Figure 1).
In addition to absolute positioning, relative positions between pairs of receivers were computed from Galileo E1, E5a, E5b, and E5 AltBOC single-frequency carrier-phase observations. Two GPS solutions covering the same time interval serve for comparison purposes. The first solution utilizes all visible GPS satellites (9 to 12 per epoch) whereas the second solution is intentionally limited to four satellites (G06, G16, G27, G29) for best comparison with the Galileo case. So-called kinematic-style processing was used where the baseline is not constrained to be unchanging and a relative-position solution is computed for each epoch of measurements. 3D standard deviations of the different solutions are listed in Table 1. The overall accuracies are at the level of a few centimeters.
Tabe 1. 3D position errors (standard deviation) of carrier-phase-based kinematic-style Galileo and GPS baseline solutions.
A slightly degraded performance is achieved for the TUMO-TUME baseline, which can be attributed to both the larger separation and the inferior multipath environment compared to the TUMW-TUME baseline.
Comparing the individual Galileo signals, the best relative positioning results were obtained for the E1 carrier-phase measurements. Interestingly, the use of carrier-phase measurements from the E5 AltBOC tracking yielded a lower performance in our test than use of either the E5a or E5b observations. Apparently, the carrier-phase tracking benefits less from the ultra-wideband signal than the code tracking, where AltBOC usually offers notably reduced noise and multipath. Besides their good performance for Galileo-only positioning, the E1 and E5a carrier-phase measurements will be particularly relevant for future relative positioning applications due to the possibility of mixed-constellation ambiguity resolution with GPS L1 and L5 signals.
For illustration, Figure 2 shows the Galileo E1 solution as well as the GPS L1 solution computed from four satellites. For the north component, the scatter of the Galileo solution is larger by a factor of two compared to GPS whereas it is on almost the same level for the east and up components as a result of the specific geometry of the satellites employed.
Figure 2. Kinematic positioning results for the TUMW-TUME baseline based on Galileo E1 (left) and GPS L1 (right) carrier-phase observations of four satellites. The standard deviations in the north, east, and up directions are given. Note the different scale of the north component.
With the recent testing of navigation messages on the first pair of IOV satellites, Galileo-based positioning as described in this article will not be limited to post-processing, but will be available to real-time users as well.
Peter Steigenberger is a staff member in the Institut für Astronomische und Physikalische Geodäsie of the Technische Universität München (TUM) in Munich, Germany.
Urs Hugentobler is the head of the Fachgebiet Satellitengeodäsie (Department of Satellite Geodesy) and the Forschungseinrichtung Satellitengeodäsie (Research Facility for Satellite Geodesy) at TUM.
Oliver Montenbruck is the head of the GNSS Technology and Navigation Group in the German Space Operations Center in Oberpfaffenhofen, Germany, and a TUM associate faculty member.
Economically, the System Differs Significantly from Its GNSS Cousins
John W. Lavrakas
In May 2007, I authored an article in GPS World looking ten years into the future and envisioning how the GNSS field would operate at that then-distant time. Reviewing my assessments, I see that I was both accurate and wide of the mark with my predictions.
The prediction that has proved accurate was that the GNSS world would be hybrid, with no one system as the sole provider of satellite-based positioning and timing services. This was hardly a risky prediction. Most in the GNSS community would have come to the same assessment.
But what I did not see coming were the advances China would take with its BeiDou program. My original assessment was based on three GNSSs only: GPS, GLONASS, and Galileo, and did not include BeiDou.
When I did my analysis in 2006, China was pretty quiet on BeiDou: no technical descriptions, no interface control document (ICD); no presentations at conferences of the Institute of Navigation. What little we knew about BeiDou was that it was a limited system, offering at best a regional solution. The original design was an active system using geosynchronous satellites, requiring each remote unit to request position from the satellite, which was calculated and sent back to the remote station.
How things have changed.
Since 2007, China has reshaped the BeiDou concept into a full-fledged modern GNSS, offering CDMA codes, navigation messages, and data rates comparable to GPS and Galileo — and lots of satellites. The ICD states in section 3.1, “When fully deployed, the space constellation of BDS consists of five geostationary Earth-orbit (GEO) satellites, twenty-seven medium Earth-orbit (MEO) satellites, and three inclined geosynchronous satellite orbit (IGSO) satellites.” No dates are provided, however, regarding attaining these numbers. So the BeiDou system promises to be on par with the other GNSSs.
Why does this matter?
While technically the BeiDou system resembles its cousins, economically it presents quite a different animal. Unlike other nations offering GNSS, China has a huge capacity for manufacturing at low cost. Considering this situation from a business perspective, a possible scenario could be that China offers GNSS chipsets that operate with BeiDou (either solely or as a hybrid with another GNSS)at extremely low prices. In doing so, China could corner the market for general purpose LBS applications (setting aside specialty receivers, such as for surveying and aviation applications). The price point would be so attractive that LBS services would employ Chinese devices in preference to the GPS ones, much like consumers purchase television sets: most come from China, and none are made in the United States any more.
China offers something, then, in this scenario that neither Russia, Europe, nor the United States can currently match. This may not be the scenario that eventually occurs, but it is possible. Other factors such as local terrestrial PNT solutions and dual-frequency improvements will come into play, but what I have described is one possible scenario. While the signal is free, the equipment is not, and when we are talking about a billion or more installations, cost is going to be a big driver.
Am I going out on a limb and saying that BeiDou will be the system of choice in another ten years or so? No, I would not go this far.
But I do say that serious competition for GNSS users (read “market share”) is now in play. Further, it is important for each GNSS operator to recognize this as they consider the services and features they choose to offer, and the impact these have in capturing their share of the market. GNSS providers now must factor the business aspect of their services as much as the technical, scientific, or safety of life. The U.S. government, for one, has gotten a bit complacent in upgrading GPS services to meet user needs, operating from a basis that it is the only GNSS on the block. It could wake up one day and find this no longer to be the case.
John Lavrakas is president of Advanced Research Corporation, where he provides consulting services on satellite navigation and fishery information systems. He has spent 32 years in GPS, supporting development of the GPS Control Segment, GPS user equipment, GPS performance analysis capabilities, and developing and marketing location-based systems. He is past president of the Institute of Navigation and an ION Fellow.
Experts ensuring that aircraft can safely rely on satellite navigation across Europe and other parts of the globe met last week to share future plans, welcoming Russian and Indian representatives for the first time, reports the European Space Agency. More and more aircraft around the globe are using satnav augmentation, with special infrastructure sharpening signal accuracy and reliability across given geographical regions.
More than 50 specialists who oversee the world’s five regional satnav augmentation systems met in Toulouse, France, January 24-25 for the latest meeting of the Satellite-Based Augmentation Systems (SBAS) Interoperability Working Group (IWG). The gathering was the first to be attended by Russia’s space agency and the Indian Bureau of Civil Aviation, to discuss their own SBAS systems.
The meeting was jointly hosted by ESA’s European Geostationary Navigation Overlay System (EGNOS) and SBAS Division with the French space agency, CNES.
Satellite augmentation systems provide ground monitoring stations and satellite transponders to sharpen satnav accuracy and reliability across geographical regions. The resulting accuracy improvements, together with information on integrity, renders satnav suitable for the vertical (as well as horizontal) guidance of aircraft and a range of other precision applications.
Today, there are three certified SBAS operational worldwide: Europe has EGNOS, designed and developed by ESA, operated by the European Satellite Service Provider and owned by the European Commission. EGNOS was made available for general users in 2009 and for aircraft landing approaches since March 2011.
The U.S. has the Wide Area Augmentation System (WAAS), developed and operated by the Federal Aviation Administration (FAA), with an extension over Canada called CWAAS (Canadian WAAS). Japan has the Multi-functional Satellite Augmentation System (MSAS), developed and operated by Japan’s Civil Aviation Bureau.
Two more systems are being developed for future certification by the International Civil Aviation Authority: Russia’s System of Differential Correction and Monitoring (SDCM), under development by Roscosmos, and India’s GPS and Geo-Augmented Navigation (GAGAN) system, under development by Indian Civil Aviation and India’s ISRO space agency.
Representatives of these five systems were joined at this 24th IWG meeting by international organisations including Eurocontrol, the European Organisation for the Safety of Air Navigation. Current combined SBAS coverage.
MediaTek Inc., a fabless semiconductor company for wireless communications and digital multimedia solutions, today announced the availability of its MT3332/MT3333, a 5-in-1 multi-GNSS receiver system-on-chip (SoC) that support the Beidou Satellite Navigation System. The Beidou system has been commercially operational since the end of 2012, and can identify a user’s location to 10 meters (33 feet), their velocity to within 0.2 meters per second, and clock synchronization signals (one-way) to within 10 nanoseconds.
The MediaTek MT3332/MT3333 can discover GPS, Beidou, GLONASS, Galileo and QZSS constellations. Featuring a multi-GNSS receiver design, the MT3332/MT3333 can reduce the cumulative distance and positioning error accumulated over time/multiple hops, and significantly improve navigation/positioning accuracy, MediaTek said. The MT3332/MT3333 also comes with excellent signal acquisition and tracking sensitivity, which efficiently enhances signal quality within dense cities, tunnels and multi-storey car-parks, while delivering a better user experience, the company said. Moreover, because of its highly integrated, low-cost and ultra-compact system architecture, the MT3332/MT3333 enables multi-GNSS receivers with the same reference board for mobile, industrial and automotive navigation applications.
“The proliferation of LBS (location-based services) using mobile applications over wireless networks such as social check-in or nearby service recommending is driving demand for greater satellite navigation performance and coverage beyond existing technologies. This will also lead to the rapid adoption of multi-GNSS receiver solutions in smartphones, tablets and automotive vehicles because LBS is now an indispensable way for people to interact/communicate with each other on a daily basis,” said SR Tsai, general manager of the Wireless Connectivity and Networking Business Unit at MediaTek. “We believe the market for Beidou-compatible multi-GNSS receivers in China will accelerate in the coming years. MediaTek will deliver new products that offer high value and are capable of meeting the evolving needs of our customers in the Beidou navigation system market through continuous product innovation. The MT3332/MT3333 [models] are designed to accelerate the realization of satellite navigation services anytime, anywhere, in a seamless fashion.”
The MT3332/MT3333 also incorporates MediaTek’s unique “AlwaysLocate” technology that can identify the state in which the user is (regardless of on-the-go or sleeping) and automatically adjust the satellite signal receiving modes for more accurate and reliable navigation services, and to save the battery power of the navigation system.
The MediaTek MT3332/MT3333 is now in mass production stage and being designed into major satellite navigation systems and mobile communication platforms worldwide.
The first switch-on of a Galileo search and rescue package shows it to be working well, according to the European Space Agency. Its activation begins a major expansion of the space-based Cospas–Sarsat network, which brings help to air and sea vessels in distress.
The second pair of Europe’s Galileo navigation satellites — launched together on October 12 last year — are the first of the constellation to host SAR search and rescue repeaters. These can pick up UHF signals from emergency beacons aboard ships and aircraft or carried by individuals, then pass them on to local authorities for rescue.
Galileo search and rescue repeater signal.
Once the satellites reached their 23,222 km-altitude orbits, a rigorous test campaign began. The turn of the SAR repeater aboard the third Galileo satellite came on January 17.
“At this stage, our main objective is to check the repeater has not been damaged by launch,” explained ESA’s Galileo SAR engineer Igor Stojkovic. “The first day was a matter of turning the repeater on and checking its temperature and power profiles were as predicted. The following day involved sending a signal to the repeater using the UHF antenna at ESA’s Redu Centre in Belgium, then picking up the reply from our L-band antenna.”
Redu’s antenna is 20 meters in diameter, so the shape of the relayed signal was captured in great detail, out of all proportion to surrounding noise.
“We can precisely measure its power, the time the relay took and so on,” added Igor.
More detailed system testing will follow, to completely prove this new type of SAR payload in orbit.
Cospas–Sarsat system.
The international system has been in use for more than three decades, saving some 31,000 lives. Cospas is a Russian acronym for “Space System for the Search of Vessels in Distress,” with Cospas standing for “Search and Rescue Satellite-Aided Tracking.” Ground stations — known as Local User Terminals — pinpoint the source of distress calls using signals relayed by participating satellites, then alert local authorities.
The GPS satellites will also provide a medium-Earth-orbit Sarsat capability and testing is underway. All nine Block IIR satellites carry experimental payloads and all IIF satellites are scheduled to. See “The Distress Alerting Satellite System” for more details.
ITT Exelis has been awarded a $2.15 million contract by the Air Force Research Laboratory (AFRL) to research the development of a small satellite navigation payload to augment the current GPS program. The GPS NAVSAT (Navigation Satellite) program seeks to provide affordable capabilities to aid end-users located in tough-to-reach environments.
“The development of smaller satellites — in terms of size, weight, power and cost — will yield greater affordability for our customers,” said Mark Pisani, vice president and general manager, Precision Instruments and Positioning, Navigation and Timing Systems, ITT Exelis Geospatial Systems. “A smaller satellite size will allow for improved launch vehicle selection flexibility.”
The goal of the 18-month initial study is to identify innovative ways to increase affordability and sustainment of the GPS program through payload weight reduction, size and power. The GPS NAVSAT will maintain similar performance capability to the existing GPS system, but will aid GPS end-users in signal-constrained environments, located in urban or mountainous terrain.
Work on GPS NAVSAT is performed in Clifton and Bloomfield, New Jersey.
For nearly 40 years, Exelis payloads and payload components have been on board every GPS satellite with more than 500 years of on-orbit life without a single mission-related failure due to Exelis equipment.
According to tracking data from stations of the International GNSS Service’s Multi-GNSS Experiment, the second Russian Luch satellite, Luch-5B, started transmitting GLONASS and GPS differential corrections on January 17, 2013, at around 11:07 UTC.
Luch-5B, launched on November 2, 2012, carries a transponder for the System for Differential Correction and Monitoring satellite-based augmentation system. The satellite, occupying an orbital slot at 16 degrees west, uses PRN code 125. Transmission tests are not continuous.
