CHAMP, SAC-C, GRACE-A, COSMIC

Data available from http://genesis.jpl.nasa.gov

(Last update: April 22, 2008)

  1. Raw data from the CHAMP, SAC-C, GRACE-A BlackJack receivers are available (level 0 or L0).

  2. Excess phase delays (L1a), bending angle profiles (L1b), refractivity, temperature, and humidity profiles (L2) from CHAMP, SAC-C, GRACE-A, COSMIC are available.

  3. We have consolidated our retrieval versions. We plan to maintain two separate versions of retrievals, to be referred to as "quick" and "postproc". The "quick" version is available more rapidly, but the "postproc" version is more accurate and is processed with a consistent algorithm throughout. We recommend that the "postproc" version be used whenever possible. Changes to our processing will be documented on this web site.

    DIFFERENCES BETWEEN QUICK AND POSTPROC VERSIONS
      quick postproc
    GPS and LEO orbits quick-look (low latency, less accurate) FLINN (higher latency, more accurate)
    temperature retrieval up to 30 km altitude; initialize with temperature from NCEP final analysis at 30 km up to 40 km altitude; initialize with temperature from ECMWF operational analysis at 40 km
    mid-to-lower troposphere humidity assumes temperature from NCEP final analysis assumes temperature from ECMWF operational analysis
    data homogeneity processing algorithm could change over time consistent processing for the entire dataset