GPS Times Four

Posted by Sam Churchill on

At a GPS Conference in Portland, Oregon, September 21-24, the four major GPS systems gave presentations on the status of their respective global GPS systems, while users and vendors talked up interoperability and cost/effectiveness.

Their are now four major independent GPS systems; the American Global Positioning System, the European Commission, Galileo and EGNOS projects, the Russian GLONASS system, and the Chinese COMPASS system. All seem to be having a variety of issues.

NovAtel today announced its next-generation OEM6 GNSS receiver platform which supports all current and upcoming GNSS constellations and satellite signals including GPS, GLONASS, Galileo, and Compass.

Air Force Space Command, which has responsibility for sustaining and maintaining the U.S. Global Positioning System, held a press conference stating that a recent GAO report questioning whether the GPS constellation could create gaps in coverage due to program defeciencies.

The GAO Report said:

The Air Force continues to face challenges to launching its IIF and IIIA satellites as scheduled. The first IIF satellite was launched in May 2010–a delay of 6 additional months for an overall delay of almost 3 1/2 years–and the program faces risks that could affect subsequent IIF satellites and launches. GPS IIIA appears to be on schedule and the Air Force continues to implement an approach intended to overcome the problems experienced with the IIF program. However, the IIIA schedule remains ambitious and could be affected by risks such as the program’s dependence on a ground system that will not be completed until after the first IIIA launch. The GPS constellation availability has improved, but in the longer term, a delay in the launch of the GPS IIIA satellites could still reduce the size of the constellation to fewer than 24 operational satellites–the number that the U.S. government commits to–which might not meet the needs of some GPS users.

Space Command disagreed, saying the GAO was overly pessimistic and didn’t adequately acknowledge what AFSPC has done to address constellation sustainment.

The U.S. currently has 31 GPS satellites in orbit, and 24 are needed to provide the high level of accuracy and reliability we enjoy today.

Sergey Revnivykh, Deputy Director General of Roscosmos’s Central Research Institute of Machine Building reported on the status and future of GLONASS.

A completely new design, GLONASS-K2, will start launching in 2013. GLONASS-K2 satellites will have a 10-year design life. The Russian system was plagued by on again, off again funding.

The European Commission published an updated Galileo Open Service Document to inform receiver manufacturers, application developers, and service providers on technical specifications of the future Galileo system and what they can expect in terms of performance. The first two satellites will be launched in November 2010, and the next two in April 2011.

The European Geostationary Navigation Overlay Service (EGNOS) is a satellite based augmentation system (SBAS) under development by the European Space Agency. Similar service is provided in North America by the Wide Area Augmentation System (WAAS), and in Asia, notably Japan, by the Multi-functional Satellite Augmentation System (MSAS).

According to Paul Verhoef, program manager of the European Union (EU) satellite navigation programs, “By the end of 2013, we will have an initial constellation of 16 satellites: 4 IOV and 12 FOC satellites. This is targeted to provide the open service, and parts of the other services: safety of life, PRS, and commercial. Completion of these will depend on the open funding questions.”

The Chinese Compass system will be a constellation of 35 satellites, which include 5 geostationary orbit (GEO) satellites and 30 medium Earth orbit (MEO) satellites, that will offer complete coverage of the globe. Frequencies for Compass are allocated in four bands: E1, E2, E5B, and E6 and overlap with Galileo.

Since September 23, 2008, Galaxy 15 and Anik F1R have been sending “Precision Approach” information to aircraft. But Galaxy 15 has gone rogue. It is now a Zombie satellite – a loose cannon on the geosynchrounous arc. Galaxy 15 has drifted out of its 133 degrees west longitude orbital slot and is now on an eastward path along the geostationary arc.

Galaxy 15 (pdf), features a unique hybrid payload configuration that broadcast GPS navigation data using L-band frequencies as part of the Geostationary Communications and Control Segment (GCCS) being implemented by Lockheed Martin for the FAA.

The purpose of GCCS (pdf) is to generate and transmit the WAAS signal in space.

The Wide Area Augmentation System enables increased position accuracy for GPS receivers. GCCS is the GPS-based navigation and landing system for aviation use to provide precision guidance to aircraft at thousands of airports and airstrips where there is currently no precision landing capability. Orbital engineered the payload and integrated it onto the existing Galaxy 15 satellite.

WhereCampPDX, an Unconference, is being held in Portland September 24-26. It’s a free, volunteer-created unconference for anyone interested in geography and technology.

Related DailyWireless stories include; Zombie Satellite Out of Control, AEHF Satellite – Billion Dollar Brick?, Satellites Collide, Chinese Destroy Satellite – Create Space Debris Field, Satellite Fallout, U.S. Antisatellite Weapon to be Tested, Geosync Spies, Space Cold War, Antartic Communications, Space Capsule, China/US Space News, Russian Satellite Hit, Pacific Satellites Fail, T-Minus 10 for Space X, Space Lasers, Satellite Jam, Advanced EHF – Wait for It,

Posted by Sam Churchill on Friday, September 24th, 2010 at 3:10 pm .

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