Table of contents:

• About the CDDIS DORIS data archive
• About the CDDIS DORIS product archive
• Obtaining access to the CDDIS DORIS data archive
• CDDIS DORIS tracking data holdings reports
• Related DORIS data and information links

About the CDDIS DORIS archive:

The DORIS data from TOPEX/Poseidon, Envisat, Jason, and the SPOT satellites are available electronically from the CDDIS and are stored in ten-day increments or cycles. The DORIS data consist of computed range rate measurements accompanied by meteorological data from sensors collocated with the beacons. The range rate computation is based on the best estimate of the beacon and satellite frequencies. These data are processed at CNES and forwarded electronically to CDDIS in the ten-day files approximately three weeks following the last day of the observation cycle.

DORIS product files. Products derived DORIS data include satellite orbits (SP1 format), time series of station coordinates (SINEX format), time series of coordinates of the TRF origin (geocenter), Earth orientation parameters (EOP), and ionosphere parameters. DORIS products archived at the CDDIS are available in subdirectories by product type at ftp://cddis.gsfc.nasa.gov/doris/products. Additional information about DORIS analysis can be found on the IDS Analysis Coordinators website.

A description of the structure of the CDDIS SLR data and product ftp archive is available.

Obtaining access to the CDDIS DORIS data archive:

The archive of DORIS data and products are accessible through anonymous ftp and the WWW at URL ftp://cddis.gsfc.nasa.gov/doris/; contact the CDDIS manager regarding questions about obtaining DORIS data. A description of the structure of the CDDIS SLR data and product ftp archive is available.

Summary of CDDIS DORIS tracking data holdings:

• DORIS spatial coverage information
• List of current and historic DORIS sites
• Map of current DORIS sites
• Query of data holdings (by station by year, satellite by year)
• DORIS temporal coverage:
  • Daily DORIS tracking data since January 1992 (TOPEX), 1994 (SPOT-2,-3, -4, and -5), 2002 (Jason-1 and Envisat)
• Data Volume:
  • DORIS tracking data in 10-day cycles: ~2 Mbytes/satellite/cycle (compressed), ~5 Mbytes/satellite/cycle (uncompressed)
• Data Format:
• CNES-defined standard exchange format for range-rate observations (04/92)
• Data Availability:
  • Daily DORIS tracking data stored in files containing 10-day cycles
  • All data on-line

Reports of CDDIS DORIS tracking data holdings:

• Yearly and monthly data holdings reports (since 1996)

Related DORIS data and information links:

• International DORIS Service (IDS)
• IDS ftp site
• IDS analysis coordination
• Example description of IDS products (from IGN)
• DORIS information at the IGN Geodetic Information System (GDIS)
• DORIS network of ground stations
• DORIS mirror site at IGN