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Latest Status Update - April 2, 2008
After a period of relatively low daily profile count the COSMIC constellation is now recovering and presently reaching again ~1500 profiles per day. FM3 had shut down its GPS receiver for several weeks because of low power conditions. FM6 produced very few profiles because of severe attitude problems. The National Space Organization (NSPO) in Taiwan recently managed to overcome both of these problems. All six satellites are functioning again - but some problems remain: FM2 has only one working solar panel, FM3 has a stuck solar array drive - both of these conditions require to turn the payloads off at times, depending on the solar angle. One of the POD navigation antennas on FM5 still has low L2 SNR so that this satellite has to be operated with only a single POD antenna. One of the high-gain occultation antennas on FM6 recently began to display low L2 signal-to-noise ratio (SNR). The cause for this new problem is still under investigation but presently it has the effect that we obtain only setting or only rising occultations from FM6.
New GPS receiver firmware has been delivered by JPL and was uploaded by NSPO to all satellites. The new firmware has modifications designed to increase the count of successfully scheduled and tracked occultations. With this new firmware it is now possible to obtain well over 400 good profiles per day per satellite provided that there are no other problems related to attitude, power, or low antenna SNR. The new firmware will also enable us track the stronger L2C signal transmitted by some of the newer GPS satellites but this has yet to be demonstrated.
The COSMIC program has received confirmation of funding for the next three years from its sponsoring US agencies, NSF, NOAA, NASA, and USAF. Taiwan is also planning on continued support for the Formosat3/COSMIC program. COSMIC is working on switching from the two commercially operated ground stations at Fairbanks, AK and Kiruna, Sweden to two NOAA-owned ground stations in Fairbanks, AK and Tromso, Norway. The new stations are presently undergoing extensive testing and the switch will take place in mid-April, 2008. After this we are planning to use the new stations for the next three years.
Real-time COSMIC products are now freely available via UNIDATA's LDM software. We hope that this new service will lead to new research and creative applications of the data to real-time applications.
March 17-18, 2008 the COSMIC program hosted an international workshop to discuss the use of radio occultation data for climate science. Presentations from this workshop can be found at the GPSRO Climate Applications Workshop Webpage
Posted by Chris Rocken, Bill Schreiner, and the CDAAC Team.
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