COSMIC Newsletter - Volume: 1
COSMIC Status Report
January 6th, 2004
Overview:
This past year has been a very good one for COSMIC. We received the
Secretary of Defense approval for the use of Minotaur rocket for COSMIC. The
spacecraft and payload development have been executed according to schedule.
COSMIC has passed Critical Design Review, Payload Qualification Review, and
Integration and Test Review. The COSMIC ground systems and the launch vehicle
development are moving forward on schedule. The COSMIC Data Analysis and
Archive Center (CDAAC) science team has conducted a detailed design review of
all software and hardware aspects related to CDAAC. They are performing
considerable testing and evaluation of the software using the CHAMP and SAC-C
radio occultation (RO) data. This will ensure the robustness of the data
processing software and allow COSMIC to produce the GPS RO data with high
quality. UCAR has appointed two postdoctoral fellows (Lidia Cucurull and Martin
Lohmann) under the sponsorship of NSF and NESDIS. Collaboration between UCAR,
JCSDA (Joint Center for Satellite Data Assimilation), NCEP and NESDIS on the
use of COSMIC RO data for operational numerical weather prediction has
progressed smoothly.
COSMIC Spacecraft and Payload Development:
The spacecraft development at the Orbital Sciences
Corporation has progressed well with a test model of the spacecraft fully built.
The first actual flight spacecraft has started integration, and is proceeding close
to schedule while working around some subcontractor delivery problems with the structure.
UCAR successfully completed the delivery of all payload Engineering Models and the first of
six of the GPS, TBB and TIP actual flight payloads. These payloads are finished with all
functional testing and the harsh vibration and thermal testing required to assure that they
will survive the launch and the space environment. JPL has performed rigorous performance
testing of the Broad Reach Engineering COSMIC GPS receiver and is pleased with the results.
The receiver appears to be performing as well, or slightly better than the CHAMP or SAC-C
receivers. Both TIP and TBB built by NRL are performing to specification or better.
Integration checkout and compatibility testing of the payloads has started and actual
integration into the 1st Flight Spacecraft bus will occur over the next few weeks.
COSMIC Ground Systems and Launch Vehicle Development:
The COSMIC ground systems development, under contract with
Universal Space Network, has been making excellent progress with completion of the Preliminary
Design Review, and all the major components of the ROCSAT-3 Alaska site on order, and most
subsystems already received and awaiting installation during spring of 2004. Subsystems for the
Kiruna Sweden site have also been ordered and most have been received as well. The Minotaur
Rocket program has been moving forward on schedule with excellent help from the US Air Force
and many contractors supporting the COSMIC program.
COSMIC Data Analysis and Archive Center (CDAAC):
Near-real time processing of CHAMP data at CDAAC is now done routinely.
Processing time from level zero to final profiles takes about 12 minutes for ~40 CHAMP profiles.
This allows us to publish results for each COSMIC data dump within about 10 minutes of reception of all needed raw data.
CDAAC has made some important changes in the way the data are processed resulting in improved reliability and accuracy.
After extensive testing we have switched lower tropospheric processing to the "Full Spectrum Inversion Technique".
We also started using an improved climatology for "statistical optimization of bending angles" at high altitudes.
This resulted in significant improvement in high latitude temperature profiles between 25 to 40 km.
CDAAC has also improved its data quality control software, resulting in more reliable automated flagging of bad data,
and it has upgraded its orbit processing software.
CDAAC is planning to receive data from the RoadRunner mission for several months prior to the COSMIC launch.
These data from an identical COSMIC GPS receiver will serve to test all aspects of the CDAAC. Agreements with the sources of
global ground based GPS fiducial data for CDAAC have not been finalized. However several potential sources
have been identified and during 2004 CDAAC expects to enter into solid agreements with NASA/JPL and the International GPS
Service (IGS) to ensure the availability of fiducial data during the COSMIC/ROCSAT-3 mission in a timely manner.
Good progress was made on clarifying the interface between CDAAC and its meteorological data users.
CDAAC data will be provided to the operational weather centers in the BUFR format via NESDIS.
Details of this format were worked out between the UK Met Office (which took the lead on this issue) and CDAAC,
were discussed at a workshop at NCEP and are now implemented into the CDAAC software. CDAAC also has begun work
on an observational operator that combines the main advantage of assimilating bending angles without the associated high computational costs.
CDAAC is also communicating with space weather users of the data but details about how to distribute ionospheric data and products still have to be worked out.
Use of GPS RO Data for Operational Weather Prediction:
Under the sponsorship of NSF and NESDIS, UCAR has recently recruited two
postdoctoral fellows, Dr. Lidia Cucurull and Dr. Martin Lohmann. The primary responsibility of Dr. Cucurull is
to participate in a collaborative project between the Joint Center for Satellite Data Assimilation, NCEP, NESDIS and UCAR,
and to facilitate the use of GPS RO data in NCEP's operational system. Dr. Cucurull has been working at the Washington DC area
since June 2003, and has moved to the World Weather Building since October 2003. Dr. Lohmann is currently working with the CDAAC
team in Boulder. After familiarizing himself with the CDAAC data processing software, he will become the major interface between
CDAAC and NESDIS on the processing and dissemination of the COSMIC data. The UCAR COSMIC team has visited several operational
centers (NCEP, ECMWF, UK Met Office, Met Service of Canada and other trips are planned). Several centers are hiring
staff and working hard to prepare for the assimilation of the CDAAC products into their models.
Issues:
There don't appear to be any issues that threaten the success of the program at this moment.
UCAR has been very pleased with the schedule and cost performance of the payload providers and various subcontractors.
UCAR has managed to stay within budget and on schedule, and even squeeze our budget to make up for slips in getting the program started.
The only potential issue is that UCAR's budget margin is very tight. At this point, we don't anticipate an overrun.
Near-Term Schedule:
The Second Radio Occultation Science Workshop is scheduled to take place on 19-20 May 2004
at Acer Aspire Park, Taiwan. With the goal to train the next generation scientists on GPS Meteorology, NCAR will hold a Summer
Colloquium on GPS Atmospheric Remote Sensing, from 20 June to 2 July 2004. The Qualification-Satellite Acceptance Review is planned for May 2004.
Transfer of the CDAAC software to Taiwan is planned for late 2004. Launch is expected for end of 2005.
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OSMIC Newsletter
