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CDAAC Data Products

We recommend to first use Re-processed data if available, then Post-processed if available, and finally Real-Time.



A new reprocessing of COSMIC radio occultation data (2006-2014, ongoing) has been performed at TACC. The name of the mission is cosmic2013 and It is available for download via

(1) the TACC FTP batch data download interface (use this interface to receive large batches of data from multiple days): http://tacc.cwb.gov.tw/cdaac/DBif/cdaac_highlevel.cgi (select 'batch data download', then select mission: cosmic2013)
and
(2) the TACC data download interface (use this interface to receive single or daily tar files): http://tacc.cwb.gov.tw/cdaac/tar/rest.html select mission cosmic2013

New features of this reprocessing include:

  • Bernese Version 5.2
  • Improved POD and excess phase processing
  • New neutral atmospheric inversion software ('newroam'), which provides much higher occultation counts (1.2 million more occultations!)
  • Uniform GPS clock corrections used throughout the reprocessing


Current release of COSMIC atmPrf and wetPrf data from TACC are now available on CISL Research Data Archive (RDA) at NCAR in dataset ds723.0
(http://rda.ucar.edu/datasets/ds723.0).

The data files are the same as on CDAAC, but organized as monthly tar balls archived on CISL HPSS. Data requests through the "Data Access" tab at the above URL will be reviewed. Once approved, the requested data will be staged for downloading via web tools. This dataset requires the same access permission as on TACC's web site.

Should you decide to download the COSMIC data from CISL RDA, please register on http://rda.ucar.edu (top page, upper left side).

Please feel free to send your questions/comments to chifan@ucar.edu.


Mission Summary

Data Access

COSMIC
COSMIC 2013: Re-Process COSMIC data with 2013 Software.
New features of this reprocessing include:
  • Bernese Version 5.2
  • Improved POD and excess phase processing
  • New neutral atmospheric inversion software ('newroam'), which provides much higher occultation counts (1.2 million more occultations!)
  • Uniform GPS clock corrections used throughout the reprocessing
COSMIC: Post Processed data - Usually available after 6 weeks
The current products have the following versions in their file names:
2009.2650 -- All file types up to atmObj, including leoOrb, comClk, occTab
2010.2640 -- All file types starting with atmPhs, including atmPrf, wetPrf

There are two different version types due to the fact that a fix was made to atmPhs processing late in the reprocessing.

COSMICRT: Real-time data from the COSMIC mission - usually available within a few hours

GPS data bits
Post Processed GPS data bits hourly archive files.
Real-Time GPS data bits hourly archive files.




LDM Distribution

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 Jose Castilleja at: castille@ucar.edu if you are interested in receiving our data sets via LDM.

We are currently providing 'ionPrf', 'atmPrf', 'wetPrf' and 'bfrPrf' files via LDM. If resources become available and sufficient interest is noted for additional files we will expand the list. Please contact Jose Castilleja at: castille@ucar.edu to let us know what file types you would like.

Posted by the CDAAC Team.


Hints for using wget for fetching files:

The CDAAC team has introduced a new way of fetching data via the web using a REST (REpresentational State Transfer) architecture.
With this interface you can fetch a daily tarball of data for a specified mission, file type and day.

  • wget -q --http-user=xxxx --http-passwd=xxxx
    http://tacc.cwb.gov.tw/cdaac/rest/tarservice/data/mission/filetype/YYYY.DDD
    Where:
    - mission is the TACC mission name i.e. cosmic
    - filetype is the file type i.e. wetPrf
    - YYYY.DDD is the day of year i.e: 2012.305

    i.e:
  • wget -q --http-user=xxxx --http-passwd=xxxx http://tacc.cwb.gov.tw/cdaac/rest/tarservice/data/cosmic/atmPrf/2012.304 -O cosmic_atmPrf_2012.304.tar

  • wget -q --http-user=xxxx --http-passwd=xxxx http://tacc.cwb.gov.tw/cdaac/rest/tarservice/data/cosmic/wetPrf/2012.301 -O cosmic_wetPrf_2012.301.tar

Pleaes Note: The above command has replaced the previous individual file wget for missions: GRACE, Metop-A, Metop-B, Metopa-2011, CHAMP, SACC and CNOFS.


Readers

BURF File Reader:
Perl Reader for our BUFR files, packaged for easy installation: RObufr-0.02.tar.gz

NetCDF Readers:
Users are welcome to go to: https://www.unidata.ucar.edu/software/netcdf/ and install the netCDF library on their machine. In addition to this library, there are netcdf interfaces available for many programming languages and products, some of which are listed at: https://www.unidata.ucar.edu/software/netcdf/software.html



COSMIC 2013 Re-Processed Data Products

COSMIC 2013 Re-Processed Data

The current products have the following versions in their file names:

COSMIC 2013 Re-Processed Data Products

  • Raw GPS Data
    • opnGps: Atmospheric occultation data in a simple custom binary format. This data file contains all high rate atmospheric data sent us by the GNSS receiver on the LEO.
      File Description  |   Data Access

    • podCrx: Raw L1 and L2 pseudo-range and carrier phase tracking data in compressed RINEX 2.20 format
      File Description  |   Data Access

  • Orbit Determination
    • leoOrb: Precise COSMIC spacecraft orbits. The orbit precision based on internal orbit overlap comparisons is on average less than 15 cm 3D RMS (0.15 mm/sec 3D velocity).
      File Description  |   Data Access

    • leoClk:Clock offset values for each LEO satellite during the period specified in the file name.
      File Description  |   Data Access

    • leoAtt: Attitude and rough position data from the COSMIC spacecraft andthe GOX navigation solutions.
      File Description  |   Data Access

    • comClk:This file contains clock offset values for each GPS satellite during the period specified in the file name. These data are in Bernese 'CLK' ASCII format.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs: Atmospheric excess phases and auxiliary data used for generating atmospheric profiles. Removal of clock errors is based on single differencing. The velocity precision of the atmPhs files is estimated to be less than 0.15 mm/sec RMS.
      File Description  |   Data Access

    • gpsBit: GPS navigation data modulation bits used for processing open loop data in the lower troposphere.
      File Description  |   Data Access

    • atmPrf: Atmospheric profiles of bending angle, refractivity, and dry temperature.
      File Description  |   Data Access

    • wetPrf: Atmospheric profiles of refractivity, temperature and water vapor. These profiles are based on 1D variational analysis using ECMWF low resolution analysis data (found in the ecmPrf files).
      File Description  |   Data Access

    • bfrPrf: Contains results in BUFR format from both atmPrf and wetPrf. The refractivity profile in bfrPrf is equivalent to the one in the corresponding atmPrf file, but may differ from the one in wetPrf.
      File Description  |   Data Access

    • sonPrf: Radio sonde comparison profiles.
      File Description  |   Data Access

    • ecmPrf:Temperature, pressure and moisture profiles generated from the ECMWF gridded analysis and colocated with occultation profiles.
      File Description  |   Data Access

    • echPrf: Temperature, pressure and moisture profiles
      File Description  |   Data Access

    • eraPrf: ERA-40 Interim reanalysis - Temperature, pressure and moisture profiles generated from the ERA interim model.
      File Description  |   Data Access

    • gfsPrf: Vertical profile through gridded NCEP operational analysis NetCDF files.
      File Description  |   Data Access

    • mmcGrd:Grid of averaged radio occultation data, an MMC grid, where MMC means Monthly Mean Climatology.
      File Description  |   Data Access

  • Total Electron Content and Ionospheric profiles
    • podTec: Absolute total electron content from the POD antennas (including ionospheric occultations). The accuracy is believed to be within 1-3 TECU, but has not been verified. Note: Data arcs from some antennas may be un-calibrated for the receiver differential code bias.
      File Description  |   Data Access

    • ionPhs: Ionospheric excess phases and auxiliary data used for generating ionospheric profiles. Note: No differencing is applied - expect receiver clock errors on L1 and L2.
      File Description  |   Data Access

    • ionPrf: Ionospheric profiles of electron density. The accuracy is genereally about 104-105 cm-3. Caveats: Some profiles may be affected by cycle-slips.
      File Description  |   Data Access

  • Tiny Iononospheric Photometer
    • tipLv1:Geo-located measurements from the Tiny Iononospheric Photometer. Each file contains data from one dump.
      File Description  |   Data Access

  • Scintillations
    • scnLv1:Derived S4 scintillation index provided every second. Caveats: Intermittent anomalies in the CA SNRs from some antennas may result in false S4 index values.
      File Description  |   Data Access



COSMIC Post Processed Data Products

COSMIC Post Processed Data

The current products have the following versions in their file names:
2009.2650 -- All file types up to atmObj, including leoOrb, comClk, occTab
2010.2640 -- All file types starting with atmPhs, including atmPrf, wetPrf

There are two different version types due to the fact that a fix was made to atmPhs processing late in the reprocessing.




While data are posted starting on day 2006.111 we strongly recommend that users focus their efforts on data collected with receiver firmware version 4.2.1 and later, starting on day 194, 2006. Because of many different issues with earlier data before day 194 CDAAC cannot support related questions/problems.

Presently we provide around 1800 neutral atmospheric profiles per day. This is lower than the planned 2500 daily profiles. The main reasons for the lower number are:
  • (a) Some satellites are still not in their final orbit and we sometimes download data only every 5 hours. To avoid receiver memory overflow some data are dumped to the air (not to a ground station).
  • (b) During orbit raising, precise orbit determination (POD) is not possible and occultations can not be processed.
  • (c) L2 phase residual dynamic range issue (expected to be solved soon).
  • (d) Data gaps in high-rate data.


We still plan to meet the 2500 sounding/day goal once the satellites gets closer to their final configuration, and remaining data quality issues are resolved.

Chris Rocken and the CDAAC Team

COSMIC Post Processed Data Products

  • Raw GPS Data
    • opnGps: Atmospheric occultation data in a simple custom binary format. This data file contains all high rate atmospheric data sent us by the GNSS receiver on the LEO.
      File Description  |   Data Access

    • podCrx: Raw L1 and L2 pseudo-range and carrier phase tracking data in compressed RINEX 2.20 format
      File Description  |   Data Access

  • Orbit Determination
    • leoOrb: Precise COSMIC spacecraft orbits. The orbit precision based on internal orbit overlap comparisons is on average less than 15 cm 3D RMS (0.15 mm/sec 3D velocity).
      File Description  |   Data Access

    • leoClk:Clock offset values for each LEO satellite during the period specified in the file name.
      File Description  |   Data Access

    • leoAtt: Attitude and rough position data from the COSMIC spacecraft andthe GOX navigation solutions.
      File Description  |   Data Access

    • comClk:This file contains clock offset values for each GPS satellite during the period specified in the file name. These data are in Bernese 'CLK' ASCII format.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs: Atmospheric excess phases and auxiliary data used for generating atmospheric profiles. Removal of clock errors is based on single differencing. The velocity precision of the atmPhs files is estimated to be less than 0.15 mm/sec RMS.
      File Description  |   Data Access

    • gpsBit: GPS navigation data modulation bits used for processing open loop data in the lower troposphere.
      File Description  |   Data Access

    • atmPrf: Atmospheric profiles of bending angle, refractivity, and dry temperature.
      File Description  |   Data Access

    • wetPrf: Atmospheric profiles of refractivity, temperature and water vapor. These profiles are based on 1D variational analysis using ECMWF low resolution analysis data (found in the ecmPrf files).
      File Description  |   Data Access

    • bfrPrf: Contains results in BUFR format from both atmPrf and wetPrf. The refractivity profile in bfrPrf is equivalent to the one in the corresponding atmPrf file, but may differ from the one in wetPrf.
      File Description  |   Data Access

    • sonPrf: Radio sonde comparison profiles.
      File Description  |   Data Access

    • ecmPrf:Temperature, pressure and moisture profiles generated from the ECMWF gridded analysis and colocated with occultation profiles.
      File Description  |   Data Access

    • echPrf: Temperature, pressure and moisture profiles
      File Description  |   Data Access

    • eraPrf: ERA-40 Interim reanalysis - Temperature, pressure and moisture profiles generated from the ERA interim model.
      File Description  |   Data Access

    • gfsPrf: Vertical profile through gridded NCEP operational analysis NetCDF files.
      File Description  |   Data Access

    • mmcGrd:Grid of averaged radio occultation data, an MMC grid, where MMC means Monthly Mean Climatology.
      File Description  |   Data Access

  • Total Electron Content and Ionospheric profiles
    • podTec: Absolute total electron content from the POD antennas (including ionospheric occultations). The accuracy is believed to be within 1-3 TECU, but has not been verified. Note: Data arcs from some antennas may be un-calibrated for the receiver differential code bias.
      File Description  |   Data Access

    • ionPhs: Ionospheric excess phases and auxiliary data used for generating ionospheric profiles. Note: No differencing is applied - expect receiver clock errors on L1 and L2.
      File Description  |   Data Access

    • ionPrf: Ionospheric profiles of electron density. The accuracy is genereally about 104-105 cm-3. Caveats: Some profiles may be affected by cycle-slips.
      File Description  |   Data Access

  • Tiny Iononospheric Photometer
    • tipLv1:Geo-located measurements from the Tiny Iononospheric Photometer. Each file contains data from one dump.
      File Description  |   Data Access

  • Scintillations
    • scnLv1:Derived S4 scintillation index provided every second. Caveats: Intermittent anomalies in the CA SNRs from some antennas may result in false S4 index values.
      File Description  |   Data Access



COSMICRT Data Products

COSMICRT Data

COSMIC Real Time data.

COSMICRT data are available from the day after COSMIC PP data availability to yesterday.

Presently we provide around 1300 neutral atmospheric profiles per day.


COSMIC Real Time data and derived products

  • Raw GPS Data
    • opnGps: Atmospheric occultation data in a simple custom binary format. This data file contains all high rate atmospheric data sent us by the GNSS receiver on the LEO.
      File Description  |   Data Access

    • goxBin:Raw binary data from the GOX/IGOR GPS occultation receiver.
      File Description  |   Data Access

  • Orbit Determination
    • occTab: Atmospheric and ionospheric occultation table. Contains information about which occultations exist in a given download (one dump of data for one LEO) and where and when they occured.
      File Description  |   Data Access

    • leoOrb: Precise COSMIC spacecraft orbits. The orbit precision based on internal orbit overlap comparisons is on average less than 15 cm 3D RMS (0.15 mm/sec 3D velocity).
      File Description  |   Data Access

    • leoClk:Clock offset values for each LEO satellite during the period specified in the file name.
      File Description  |   Data Access

    • leoAtt: Attitude and rough position data from the COSMIC spacecraft andthe GOX navigation solutions.
      File Description  |   Data Access

    • leoPVT:The same navigation data from the GOX that is contained in the leoAtt files, but packaged in a format usable by NSPO satellite operations.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs: Atmospheric excess phases and auxiliary data used for generating atmospheric profiles. Removal of clock errors is based on single differencing. The velocity precision of the atmPhs files is estimated to be less than 0.15 mm/sec RMS.
      File Description  |   Data Access

    • gpsBit: GPS navigation data modulation bits used for processing open loop data in the lower troposphere.
      File Description  |   Data Access

    • atmPrf: Atmospheric profiles of bending angle, refractivity, and dry temperature.
      File Description  |   Data Access

    • wetPrf: Atmospheric profiles of refractivity, temperature and water vapor. These profiles are based on 1D variational analysis using GFS 47 level 12 hour forecast data (found in the avnPrf files).
      File Description  |   Data Access

    • bfrPrf: Contains results in BUFR format from both atmPrf and wetPrf. The refractivity profile in bfrPrf is equivalent to the one in the corresponding atmPrf file, but may differ from the one in wetPrf.
      File Description  |   Data Access

    • avnPrf:Temperature, pressure and moisture profiles generated from the NCEP GFS 12 hour forcast files and colocated with occultation profiles. These profiles are used by the real time CDAAC process as a first guess for determining moisture below 10km and for comparison purposes.
      File Description  |   Data Access

  • Total Electron Content and Ionospheric profiles
    • podTec: Absolute total electron content from the POD antennas (including ionospheric occultations). The accuracy is believed to be within 1-3 TECU, but has not been verified. Note: Data arcs from some antennas may be un-calibrated for the receiver differential code bias.
      File Description  |   Data Access

    • ionPhs: Ionospheric excess phases and auxiliary data used for generating ionospheric profiles. Note: No differencing is applied - expect receiver clock errors on L1 and L2.
      File Description  |   Data Access

    • ionPrf: Ionospheric profiles of electron density. The accuracy is genereally about 104-105 cm-3. Caveats: Some profiles may be affected by cycle-slips.
      File Description  |   Data Access

  • Scintillations
    • scnLv1:Derived S4 scintillation index provided every second. Caveats: Intermittent anomalies in the CA SNRs from some antennas may result in false S4 index values.
      File Description  |   Data Access



GPS Data Products

GPS Data

GPS Post Processed data.


FID data and derived products



GPS Data Products

GPS Data

GPS Real Time data.


Real-time GPS data