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CDAAC Data Products

CDAAC Climate Re-Processing Status

The CDAAC processes raw RO data into atmospheric profiles in near real time (within ~90 minutes of observation), 2-3 months after real-time with currently developed algorithms (i.e. post-processed solution), an also periodically re-processes all RO missions every 1-2 yrs with consistent software and algorithms to provide the most accurate and stable products for use in climate studies.

Newly re-processed data products are now being made available on the CDAAC website as soon as they are processed and vetted. The Table below summarizes the availability of these consistently re-processed data. Although the product version numbers differ, these data products are considered consistent (i.e. processed with similar algorithms) by the CDAAC Team and are the most suitable CDAAC products to use for climate studies. 

Mission                 Date Range                      Product Version #
----------              ----------------                ------------------------
GPSMET                  1995.111-1997.047               2007.3200 (prime time data, GPS Anti-spoofing off)
GPSMETAS                1995.111-1997.047               2007.3200 (non-prime time data, GPS Anti-spoofing on)
CHAMP                   2001.139-2008.274               2009.2650
COSMIC                  2006.194-2012.243               2010.2640
GRACE-A                 2007.059-2012.184               2009.2650-2010.2640
Metop-A/GRAS            2007.273-2011.365               2011.2980 (climate reprocessing mission 'metopa2011')
Metop-A/GRAS            2012.001-2012.121               2011.2980 and others (post-processing mission 'metopa')
SAC-C                   2006.068-2011.215               2010.2640
TerraSAR-X              2008.041-2012.151               2010.2640
C/NOFS                  2010.060-2011.365               2010.2640

NOTE:
---------
- COSMIC data from early in the mission before 2006.194 are not high quality due to receiver tracking issues.
- C/NOFS will be published as soon as possible.
----------------------------------------------------------------------------------

It has been noted by Barbara Pirsher (Wegener Center/UCAR) that the 'wet' temperature and pressure values from the 'wetPrf' profiles are not consistent between missions. This is due to the fact that different background model data were used in the 1D-VAR assimilation that is used to compute these profiles. This table shows the model currently used for each mission available on the CDAAC web site. We plan on using the ERA-40 interrim reanalysis for future reprocessings. 

Mission              Background model
----------          -----------------
GPSMET               ECMWF analysis
GPSMETAS             ECMWF analysis
CHAMP                ECMWF analysis
COSMIC               ERA-40 interrim reanalysis
GRACE-A              ERA-40 interrim reanalysis
Metop-A/GRAS         ERA-40 interrim reanalysis
SAC-C                ERA-40 interrim reanalysis
TerraSAR-X           ERA-40 interrim reanalysis
C/NOFS               ERA-40 interrim reanalysis

Posted by Bill Schreiner and the CDAAC Team.
----------------------------------------------------------------------------------

It has been noted by Shu-Ya Chen (UCAR) that some BUFR files processed before the end of 2010 can contain an error in longitude for certain levels. Those occultations that cross the date line and thus jump from -180 to 180 degrees longitude can have some values scambled or incorrect in the area of the dateline crossing.

This is fixed in recent BUFR files and will be fixed for all files at the time of the next reprocessing.

Posted by Doug Hunt and the CDAAC Team.


Mission Summary
Data Access

COSMIC 		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

SACC 		SACC: Post Processed data from the Argentinian SAC-C satellite
SACCRT: Real-time data from the Argentinian SAC-C satellite

C/NOFS 		CNOFS: Post Processed data from the US Air Force C/NOFS satellite
CNOFSRT: Real-time data from C/NOFS

GPSMET 		GPSMET: Post Process data from the proof-of-concept GPS/MET experiment

GPSMETAS 		GPSMETAS: Post Process data from the proof-of-concept GPS/MET experiment - Lower quality data with GPS Anti-Spoofing enabled.

GRACE 		GRACE: Post Process data from the GRACE (Gravity Recovery and Climate Experiment) mission.

TerraSar-X 		TerraSAR-X: Post Process data from the German TerraSAR-X mission.

MetOp-A 		MetOp-A: metopa mission. Post Processed data from the MetOp-A satellite. Varying software, processed month-to-month starting in Jan 2012.
MetOp-A: metopa2011 mission. Climate reprocessing of Metop-A data from 2007.273 to 2011.365. Consistent software and parameters used.

CHAMP 		CHAMP: Post Processed data - usually available after 6 weeks

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 Karl Hudnut at: khudnut@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 Karl Hudnut at: khudnut@ucar.edu to let us know what file types you would like.

Posted by the CDAAC Team.

Hints for using wget for fetching CDAAC files from CDAAC:

Here is one recipe for fetching all cosmic real time atmPrf files for one day:

wget -e robots=off -nd -np -r -l 10 -w 2 --http-user=xxxx --http-passwd=xxxx http://cosmic-io.cosmic.ucar.edu/cdaac/login/cosmicrt/level2/atmPrf/2006.207/

The option -e robots=off ignores the existing robots.txt file.

The option -np (no parents) is important. Without it, all manor of files from throughout the site will be loaded, I think due to the links back to the main page which are everywhere.

The option -r (recursive fetch) is necessary unless there is just one file you want to fetch.

The option -l 10 (limit of recursive depth to 10 levels) is necessary in order to get around the default 5 level depth.

The option -nd dumps all fetched files into your current directory. Otherwise a directory hierarchy will be created: cosmic-io.cosmic.ucar.edu/cdaac/login/cosmicrt/level2/atmPrf/2006.207

The option -w 2 tells wget to wait two seconds between each file fetch so as to have pity on our poor web server.

Tips for 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 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
    • podGps:Raw L1 and L2 pseudo-range and carrier phase tracking data in BINEX 0x7f-00 format.
      File Description  |   Data Access

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

    • 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

    • goxSOH: Log and State-Of-Health messages from the GOX.
      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

    • occTab: Table of occultations for one dump in netCDF 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

    • ncpPrf: Temperature, pressure and moisture profiles generated from the NCEP GFS analysis and colocated with occultation profiles. These profiles are used for comparison purposes.
      File Description  |   Data Access

    • ecmPrf: Temperature, pressure and moisture profiles generated from the ECMWF analysis and colocated with occultation profiles. These profiles are used for comparison purposes.
      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

  • 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

    • leoDcb: Differential Code Biases for COSMIC receivers/antennas. The accuracy is believed to be within 1-2 TECU, but has not been verified.
      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
    • scnRaw:Raw amplitude scintillation data from the GPS receiver. The receiver provides the RMS of the intensity fluctuations over one second based on 50 Hz sampling.
      File Description  |   Data Access

    • 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

  • Tiny Ionospheric Photometer

COSMICRT Data Products

COSMICRT Data

COSMIC Real Time data.

Currently COSMICRT data are posted since doy 2010.335 up to present day.

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 Real Time data and derived products

  • Raw GPS Data
  • 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

    • leoPor:Two-week predicted COSMIC spacecraft orbits. The accuracy is generally within a few kilometers. Caveat: Some orbit predictions may be erroneous due to spacecraft maneuvering.
      File Description  |   Data Access

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

    • leoTLE:Two line elements files for the COSMIC spacecraft orbits. These are fetched from celestrak.com and then given the correct COSMIC spacecraft ID.
      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

    • comClr:Clock offset values for each GPS satellite during the period specified in the file name. The clock values are kept at the same rate as the high rate fiducial data (one second).
      File Description  |   Data Access

    • occTab: Table of occultations for one dump in netCDF format.
      File Description  |   Data Access

    • pocTab:Table of predicted occultations for a future day netCDF 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 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

    • leoDcb: Differential Code Biases for COSMIC receivers/antennas. The accuracy is believed to be within 1-2 TECU, but has not been verified.
      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
    • scnRaw:Raw amplitude scintillation data from the GPS receiver. The receiver provides the RMS of the intensity fluctuations over one second based on 50 Hz sampling.
      File Description  |   Data Access

    • 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

  • Tiny Ionospheric Photometer

SACCRT Data Products

SACCRT Data

SACC Real Time data.


SACCRT data and derived products

  • Raw GPS Data
  • Orbit Determination
  • Atmospheric Profiles
    • atmObj: Atmospheric occultation object file. Contains file names of all files needed to process an atmospheric occultation (excess phase + inversion).
      File Description  |   Data Access

    • atmPhs: Atmospheric excess phase file. This file is analogous to the GPS/MET 'occ' level 2 files, but it is in NetCDF format instead of tab-delimited ASCII.
      File Description  |   Data Access

    • atmPrf: An atmospheric profile without moisture information.
      File Description  |   Data Access

    • avnPrf: Temperature, pressure and moisture profiles generated from the NCEP AVN 12 hour forcast files and colocated with occultation profiles.
      File Description  |   Data Access

    • wetPrf: An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf: A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access


SACC data and derived products

SACC Data

SACC Post Processed data.

  • Raw GPS Data
  • Orbit Determination
    • leoOrb:LEO orbit specification file. Contains LEO orbit info for the period of the download (for real time files) or for one day (for post-processed files). Specified in SP3 format
      File Description  |   Data Access

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

    • occTab:Atmospheric and ionospheric occultation table.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs:Atmospheric excess phase file. This file is analogous to the GPS/MET 'occ' level 2 files, but it is in NetCDF format instead of tab-delimited ASCII.
      File Description  |   Data Access

    • atmPrf:An atmospheric profile without moisture information.
      File Description  |   Data Access

    • wetPrf:An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf:A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access

    • sonPrf:Temperature, pressure and moisture profiles generated from radio sonde data from NCAR mass store
      File Description  |   Data Access

    • ncpPrf:Temperature, pressure and moisture profiles generated from the NCAR/NCEP reanalysis and colocated with occultation 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

    • 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

  • 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

    • leoDcb: Differential Code Biases for COSMIC receivers/antennas. The accuracy is believed to be within 1-2 TECU, but has not been verified.
      File Description  |   Data Access


CNOFS Data Products

CNOFS Data

C/NOFS Post-Processed data


CNOFS data and derived products


CNOFSRT Data Products

CNOFSRT Data

C/NOFS Real Time data.


CNOFSRT data and derived products

  • Atmospheric Profiles
    • atmPrf: An atmospheric profile without moisture information.
      File Description  |   Data Access

    • avnPrf: Temperature, pressure and moisture profiles generated from the NCEP AVN 12 hour forcast files and colocated with occultation profiles.
      File Description  |   Data Access

    • wetPrf: An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf: A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access


GPSMET data and derived products

GPSMET Data

Data available for the time period of: 1995.100-128; 1995.170-305 and 1997.033-054

  • Raw GPS Data
  • Level 1b data products
    • fidTrp:Tropospheric Zenith Delays above fiducial sites. Stored in the ASCII Bernese TRP format (see Bernese GPS Software Version 4.0). Each file contains one hour of data.
      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

    • gpsClk:GPS clocks extracted from IGS GPS orbits. Contains GPS clock offset information in Berne 'CLK' format.
      File Description  |   Data Access

    • leoOrb:LEO orbit specification file in SP3 format. Contains LEO orbit info for one day.
      File Description  |   Data Access

    • occTab:Atmospheric and ionospheric occultation table in netCDF format.
      File Description  |   Data Access

  • Atmospheric Profiles

GPSMETAS data and derived products

GPSMETAS Data

Data available for the time period of: 1995.224-242; 1995.328-349; 1996.022-042; 1996.076-097; 1996.128-148; 1996.186-207; 1996.237-258; 1996.293-312; and 1996.350-1997.009

  • Raw GPS Data
  • Level 1b data products
    • fidTrp:Tropospheric Zenith Delays above fiducial sites. Stored in the ASCII Bernese TRP format (see Bernese GPS Software Version 4.0). Each file contains one hour of data.
      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

    • gpsClk:GPS clocks extracted from IGS GPS orbits. Contains GPS clock offset information in Berne 'CLK' format.
      File Description  |   Data Access

    • leoOrb:LEO orbit specification file in SP3 format. Contains LEO orbit info for one day.
      File Description  |   Data Access

    • occTab:Atmospheric and ionospheric occultation table in netCDF format.
      File Description  |   Data Access

  • Atmospheric Profiles

GRACE data and derived products

GRACE Data

GRACE Post Processed data.

  • Raw GPS Data
  • Orbit Determination
    • leoOrb:LEO orbit specification file. Contains LEO orbit info for the period of the download (for real time files) or for one day (for post-processed files). Specified in SP3 format
      File Description  |   Data Access

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

    • occTab:Atmospheric and ionospheric occultation table.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs:Atmospheric excess phase file. This file is analogous to the GPS/MET 'occ' level 2 files, but it is in NetCDF format instead of tab-delimited ASCII.
      File Description  |   Data Access

    • atmPrf:An atmospheric profile without moisture information.
      File Description  |   Data Access

    • wetPrf:An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf:A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access

    • sonPrf:Temperature, pressure and moisture profiles generated from radio sonde data from NCAR mass store
      File Description  |   Data Access

    • ncpPrf:Temperature, pressure and moisture profiles generated from the NCAR/NCEP reanalysis and colocated with occultation 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

    • 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

  • 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

    • leoDcb: Differential Code Biases for COSMIC receivers/antennas. The accuracy is believed to be within 1-2 TECU, but has not been verified.
      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


TerraSAR-X data and derived products

TerraSAR-X Data

TSX Post Processed data.

  • Raw GPS Data
  • Orbit Determination
    • leoOrb:LEO orbit specification file. Contains LEO orbit info for the period of the download (for real time files) or for one day (for post-processed files). Specified in SP3 format
      File Description  |   Data Access

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

    • occTab:Atmospheric and ionospheric occultation table.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs:Atmospheric excess phase file. This file is analogous to the GPS/MET 'occ' level 2 files, but it is in NetCDF format instead of tab-delimited ASCII.
      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:An atmospheric profile without moisture information.
      File Description  |   Data Access

    • wetPrf:An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf:A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access

    • sonPrf:Temperature, pressure and moisture profiles generated from radio sonde data from NCAR mass store
      File Description  |   Data Access

    • ncpPrf:Temperature, pressure and moisture profiles generated from the NCAR/NCEP reanalysis and colocated with occultation 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

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

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

    • leoDcb: Differential Code Biases for COSMIC receivers/antennas. The accuracy is believed to be within 1-2 TECU, but has not been verified.
      File Description  |   Data Access


MetOp-A post-processed data and derived products. The metopa mission which runs month-to-month using the most recent CDAAC software starting in Jan 2012

MetOp-A Data

MetOp-A Post Processed data.

  • Raw GPS Data
  • Orbit Determination
    • leoOrb:LEO orbit specification file. Contains LEO orbit info for the period of the download (for real time files) or for one day (for post-processed files). Specified in SP3 format
      File Description  |   Data Access

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

    • occTab:Atmospheric and ionospheric occultation table.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs:Atmospheric excess phase file. This file is analogous to the GPS/MET 'occ' level 2 files, but it is in NetCDF format instead of tab-delimited ASCII.
      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:An atmospheric profile without moisture information.
      File Description  |   Data Access

    • wetPrf:An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf:A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access

    • sonPrf:Temperature, pressure and moisture profiles generated from radio sonde data from NCAR mass store
      File Description  |   Data Access

    • ncpPrf:Temperature, pressure and moisture profiles generated from the NCAR/NCEP reanalysis and colocated with occultation 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

    • 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

  • 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

    • leoDcb: Differential Code Biases for COSMIC receivers/antennas. The accuracy is believed to be within 1-2 TECU, but has not been verified.
      File Description  |   Data Access


MetOp-A climate processing. The metopa2011 mission which runs from 2007.273 to 2011.365 (with some gaps in 2007-2008 due to unavailability of data). Consistent CDAAC software and parameters were used.

MetOp-A Data

MetOp-A Climate Reprocessing (metop2011 mission)

  • Raw GPS Data
    • mtpLv0:This file contains level 0 (raw binary) data from the MetOp-A satellite.
      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

    • mtpPst: Atmospheric occultation data in the opnGps binary format.
      This data file contains high rate occultation data at a 50Hz rate stored per-occultation. Also included are .png files showing open- and closed-loop doppler, doppler model and SNRs for each occultation.
      File Description  |   Data Access

  • Orbit Determination
    • leoOrb:LEO orbit specification file. Contains LEO orbit info for the period of the download (for real time files) or for one day (for post-processed files). Specified in SP3 format
      File Description  |   Data Access

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

    • occTab:Atmospheric and ionospheric occultation table.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs:Atmospheric excess phase file. This file is analogous to the GPS/MET 'occ' level 2 files, but it is in NetCDF format instead of tab-delimited ASCII.
      File Description  |   Data Access

    • atmPrf:An atmospheric profile without moisture information.
      File Description  |   Data Access

    • wetPrf:An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf:A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access

    • sonPrf:Temperature, pressure and moisture profiles generated from radio sonde data from NCAR mass store
      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


CHAMP Data Products

CHAMP Data

CHAMP post processed data - usually available after 6 weeks

Data available for the time period of: 2001.139 - 2008.278


CHAMP data and derived products

  • Raw GPS Data
  • Orbit Determination
    • leoOrb:LEO orbit specification file. Contains LEO orbit info for the period of the download (for real time files) or for one day (for post-processed files). Specified in SP3 format
      File Description  |   Data Access

    • occTab:Atmospheric and ionospheric occultation table.
      File Description  |   Data Access

  • Atmospheric Profiles
    • atmPhs:Atmospheric excess phase file. This file is analogous to the GPS/MET 'occ' level 2 files, but it is in NetCDF format instead of tab-delimited ASCII.
      File Description  |   Data Access

    • atmPrf:An atmospheric profile without moisture information.
      File Description  |   Data Access

    • wetPrf:An atmospheric occultation profile with moisture information included.
      File Description  |   Data Access

    • bfrPrf:A low resolution (adjustable, currently 200 meter) atmospheric profile in the BUFR format useful to weather modelers.
      File Description  |   Data Access

    • sonPrf:Temperature, pressure and moisture profiles generated from radio sonde data from NCAR mass store
      File Description  |   Data Access

    • ncpPrf:Temperature, pressure and moisture profiles generated from the NCAR/NCEP reanalysis and colocated with occultation 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

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

  • Total Electron Content and Ionospheric profiles
    • ionTec:Absolute total electron content from the occultation antenna. The accuracy is believed to be within 1-3 TECU, but has not been verified.
      File Description  |   Data Access

    • podTec:Absolute total electron content from the zenith POD antenna. The accuracy is believed to be within 1-3 TECU, but has not been verified.
      File Description  |   Data Access

    • leoDcb:Differential Code Biases for the CHAMP receiver/antennas. The accuracy is believed to be within 1-2 TECU, but has not been verified.
      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


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








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