All six satellites are operating. The daily occultation count ranges from 1600-2200 good neutral atmospheric profiles. FM6 has good SNRs for both high gain antennas, an improvement since the April 2008 update, which is believed to be caused by lower antenna temperatures. The daily occultation count remains limited by the problems described previously: 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. While the daily count for the mission remains lower than anticipated individual well functioning satellites like FM4 can generate over 500 high-quality soundings on good days.

After uploading a new version of JPL-modified firmware the COSMIC mission has collected the first profiles tracking the new GPS L2C signal. The data are still undergoing testing but initial results indicate significantly improved penetration into the lower troposphere when tracking the L2 phase. Open loop tracking of L2C is also performed but CDAAC software is still being modified to process those data.

The new NOAA-supported ground stations in Fairbanks, AK, and Tromsoe Norway, are performing well. After some initial-startup problems reliability is now as good as it has been before we switched ground stations. An additional ground station in McMurdo, Antartica, is now being prepared for support of 6 COSMIC passes per day. This ground station is owned by NSF and operated by NASA and it is expected to reduce the latency of some COSMIC products.

Posted by Chris Rocken, Bill Schreiner, and the CDAAC Team.

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.

Please note:

We now have the capability to distribute our data via LDM -- Local Data Manager -- an event-driven data distribution system.
Web Link: http://www.unidata.ucar.edu/software/ldm/
Please contact Karl Hudnut at: khudnut@ucar.edu if you are interested in receiving our data sets via LDM.
We are currently sending 'wetPrf' and 'bfrPrf' files via LDM and will expand this list if there is sufficient interest, so please also specify the file types you would like.

Posted by the CDAAC Team.

Please note: COSMIC and CHAMP highlevel products have been reprocessed and are available on our Website.

Posted by the CDAAC Team.

After a gap of 2 months (from day 252 - 317, 2007) FM6 started to provide data again on day 318 of 2007. The reasons for this long gap are still under investigation. Data from FM6 are looking good and are provided to users. Power issues with FM2 and FM3 remain unchanged and the amount of data obtained from these satellites depends on the solar angle.

We have discovered an anomaly in CDAAC data processing which has now been corrected. During periods when the LEO receiver time and GPS time differed significantly our profiles were affected by added noise. This was noticeable above 20-25 km altitude. These periods of added noise were sporadic and different for different FMs. Our real-time processing software has been fixed to account for these clock offset periods, is now undergoing testing, and is scheduled to run on our production machine starting Monday November 19, 10am Boulder time. We are also beginning to re-process all our post processed data. Re-processing should be completed in a few weeks. As part of this re-processing, COSMIC post processed data (mission 'cosmic') will be temporarily unavailable.

We have been working with JPL to find ways to increase the percentage of profiles that are inverted successfully. Sometimes as many as 50% of receiver-scheduled profiles fail in the CDAAC processing chain for a variety of reasons. Upgraded firmware, which will be uploaded to LEO receivers, with changes in the way reference satellites are scheduled, and in the way L2 is tracked for setting occultations, is expected to increase the percentage of profiles that pass successfully through all of our processing steps.

Posted by Chris Rocken, Bill Schreiner, and the CDAAC Team.

Please note: We are reprocessing CHAMP highlevel products. These will be unavailable for few weeks starting 11/09/2007

Posted by the CDAAC Team.

The daily occultation count has recently dropped to ~1200 due to several reasons. (a) We have lost contact with FM6. Efforts are underway to re-establish contact to this satellite. (b) The solar panels of FM3 are stuck resulting in non-optimal power and limited payload operation for this spacecraft. Efforts are underway to determine what happened and to try to move the solar array drive (SAD). (c) Orbit raising for FM3 has been halted and the satellite will remain at ~700 km altitude for now. (d) FM2 still is operating with only one solar panel and payloads are operated only part of the time. FM1 orbit raising has begun.

CDAAC plans to switch to processing with version 2.0 software during the week of Sept 17-21, 2007, which should result in a slightly improved success rate of profiles that pass our quality control. We anticipate an improvement of ~ 5%. New flight software which also should increase the number of occultations that we track is presently undergoing testing at JPL. Once these tests are completed we expect to upload this software in the next few weeks.

Meteo France has begun use of COSMIC data operationally - making it the 4th operational weather center to do so.

Posted by Chris Rocken, Bill Schreiner, and the CDAAC Team.

The satellite constellation is approaching final deployment with only one more spacecraft, FM1, remaining its initial 500-km orbit.

Presently the system is producing 1500-1700 good neutral atmospheric soundings per day with an average latency of about 2 hours. New firmware (FB 4.4) was provided by JPL and uploaded to satellites FM5 and FM6. This firmware enables operations if only the fore navigation antenna (POD) is working and was needed for FM5 and FM6 which experience intermittent problems with one of their two navigation GPS antennas. The firmware also improved L2 tracking and produced the first tracking data of the new L2C GPS signal. However it was decided to not upload FB 4.4 to all satellites until several firmware improvements and bug fixes can be applied. Power limitations on FM2, orbit raising of FM3, low SNRs on one of the navigation antennas of FM5, and recent attitude control problems on FM6 limit the number of daily profiles to the current level.

CDAAC software version 2.0 is nearing completion with several improvements including post processing capability, new data gap processing, and improved phase data filtering. CDAAC has begun re-processing of all COSMIC data. This analysis is in progress and it takes about 18 hours of CPU time on our new Linux cluster to process 1 month of COSMIC data.

Don't forget to register and submit an abstract for the Second Formosat-3 / COSMIC Workshop in BoulderOctober 22-24.

Posted by Chris Rocken and the CDAAC Team

The number of daily soundings has temporarily dropped below 1000. This is caused by several issues. (a) We have uploaded new GPS receiver firmware version 4.4 to FM6. While we are testing/validating this new firmware this satellite has been taken off line. (b) FM3 is currently raised - this affects data from FM3 and also the number of data dumps from the other spacecraft. (c) FM2 is only operated during a small fraction of the day because of power limitations. (d) FM5 is producing only very few rising occultations because of continued low L2 SNRs on the fore POD antenna. We expect that most of these problems can be resolved soon and that we will be able to provide more daily soundings.

Posted by Chris Rocken and the CDAAC Team

Reprocessed CHAMP data from 2001 to 2007 is now available online.
To access it please go to: http://cosmic-io.cosmic.ucar.edu/cdaac/login/champ/
These results include more occultations and are better suited to climate applications, since they are all processed with the same code.

Posted by the CDAAC Team

Count of daily occultations still ranges between 1400-1800 soundings per day. A GPS receiver firmware upgrade is undergoing testing at JPL. This upgrade is expected to further improve profile quantity and quality and it is designed to help with the Signal to Noise Ratio (SNR) drop anomalies mentioned below. All six satellites and payloads are functioning. Only FM1 and FM3 remain in the low orbits, all other satellites have been raised to about 800 km The final constellation shall be reached by the end of October 2007. FM2 appears to have lost one of its two solar panels and operation of its payloads had to be reduced. FM2 TIP and TBB have been turned off and GPS is operated, depending on solar angle between 10%-90% of the time. We are still experiencing periodic drops in SNR from some of the GPS antennas in the constellation which leads to periodic data loss. The reason for these events is under investigation.

The COSMIC team is working with NOAA and the UKMO to improve the latency of the BUFR profiles distributed over the GTS to operational centers. These BUFR files are frequently delayed many hours. This is expected to be fixed very soon. NOAA/NCEP went operational with COSMIC on May 1st 2007 along with the implementation in operations of the new NCEP's Global Data Assimilation System (GSI/GFS). The UKMO has begun operational assimilation of COSMIC profiles on May 15, 2007, joining the ECMWF and NOAA/NCEP.

Posted by Chris Rocken, Dave Ector and Lidia Cucurull.

We have had some satellite problems over the past couple of months with satellites FM1, FM2 and FM6. These problems have reduced the number of soundings from a peak of over 2400. We have recovered on FM1 and FM6 but due to remaining problems with FM2 and orbit raising maneuvers on FM4 we are presently generating ~1700 profiles / day. The cause of the anomalies with the GPS receivers on FM1 and FM6 has not yet been resolved. All three FM2 payloads are currently turned off while problems are being investigated. We are hoping for a resolution to these problems and remain committed to the goal of 2500 neutral atmospheric profiles per day. Satellites are still being raised with half of the satellites in their final orbits above 800Km. Both NOAA/NCEP and UKMO are planning to begin using COSMIC RO data operationally within a few months. NOAA / SEC has expressed interest to obtain COSMIC space weather data in real-time and the COSMIC team is working with them on this.

JCSDA: GSI/GFS with COSMIC data is running in real time in parallel to operations for implementation in operations as the new NCEP Global Data Assimilation System.

Posted by Chris Rocken, Dave Ector and Lidia Cucurull.

Satellites are are still being raised to move into final position. New version 4.3 firmware has now been loaded to all 6 satellite's RO receivers. Half of the satellites are now in their final orbits of above 800Km. Orbit raising is continuing on the other satellites, and will continue over the next 10 months - though we are now beginning to see fairly even daily global coverage with the COSMIC constellation. Numbers of payload data downloads have increased considerably to between 50-60 per day, reducing data latency and increasing numbers of soundings which can be used for realtime weather forecasting. We are presently experiencing an anomaly with one of the 2 POD antennas on FM6 - while investigating this, CDAAC has taken FM6 off-line. Prior to this we had reached over 2200 soundings per day. Assuming that all six satellites remain fully functional we expect that the mission requirement of 2500 atmospheric soundings per day should be reached, after the next firmware upgrade that we are discussing with JPL. TIP and TBB operations are ongoing successfully. Radio occultation profiles in WMO approved BUFR format are now distributed via NOAA/NESDIS through the GTS. CDAAC is pushing the profiles to NESDIS with about 90-min latency of on-orbit collection - clearly exceeding the mission goal of 180 minutes average latency.

JCSDA: Started a parallel run with the assimilation of COSMIC soundings with the final (and implementable) version of the GSI/GFS code. We selected refractivity as immediate use of COSMIC in operations.

Posted by Chris Rocken, Dave Ector and Lidia Cucurull.

All satellites are healthy and orbit raising is still continuing with 3 satellites near final orbit. All 6 are still being spread apart to maximize download capability. We are averaging around 1600 soundings per day. Days which have orbit raising activities (satellite burns) have reduced numbers of soundings -- GPS payload is turned off on the scheduled satellite. The constellation is in the process of receiving a new firmware upload for the GPS RO receivers which will add some capability including addition of capability for S4 index collection. TIP and TBB operations are ongoing successfully.
Another milestone development is that the ECMWF began using the COSMIC data operationally on Dec. 12, 2006.

JCSDA: Continuing to do parallel data assimilation runs with a new version of the GSI/GFS code. Validation against radiosondes shows a global reduction of the bias and RMS error when GPS RO observations are being assimilated into the system. Final tuning of the next generation NCEP global data assimilation system is underway prior to operational implementation.

Posted by Chris Rocken, Dave Ector and Lidia Cucurull.