DORIS Data Products and Holdings

Data Holdings

DORIS data are provided in two possible forms, depending upon the type of DORIS receiver on-board the satellite. Missions prior to Jason-2 (e.g., SPOT, TOPEX/Poseidon, Jason-1, and Envisat) supply data in multi-day (typically 10 days) files corresponding to the mission’s data processing arc. Missions launched after, and including, Jason-2 in 2008 (e.g., Jason-2, CryoSat-2, HY-2A, SARAL, and future satellites) utilize a new multi-channel DORIS receiver, which is capable of tracking up to seven beacons simultaneously. These missions provide data in daily files in addition to these multi-day files.

The multi-day files are in a DORIS-specific format; these files contain multiple days of data corresponding to the specific satellite’s processing cycle. The new multi-channel DORIS receiver provides both Doppler and phase observations; data from this model are archived in both multi-day DORIS-formatted files and daily files in DORIS Receiver Independent Exchange (RINEX) format respectively.

Data Summary

The data from each satellite are stored in separate files and directories, by satellite. DORIS data are organized in subdirectories by:

• File content (multi-day files, daily files)
• Satellite
• Year

DORIS Data Holdings

• Daily Raw DORIS Data
• Multi-Day Preprocessed DORIS Data
• Quaternion Files

Spatial Coverage

• List of DORIS sites
• Map of DORIS sites

Temporal Coverage

• Multi-day files from 1990 through present
• Daily data files from 2008 through present
• Coverage: satellite dependent

Data Volume

• DORIS data in multi-day files: ~3-7 Mbytes/satellite/cycle (compressed)
• DORIS data in daily files: ~2 Mbytes/satellite/day (compressed)

Data Formats

• DORIS data in multi-day files: DORIS internal format
• DORIS data in daily files: Receiver Independent Exchange (RINEX) format

DORIS data are available from the CDDIS in subdirectories by satellite and year (for RINEX data).

The starting directory for these files is: https://cddis.nasa.gov/archive/doris/data/

Append the following directory and file names to the starting directory:

SAT/SATdata###.VVV.Z  (multi-day files)

SAT/YYYY/SATrxYYDDD.VVV.Z   (RINEX files)

as described in the table below.

Learn more about DORIS-equipped satellites.

Product Holdings

NASA’s Crustal Dynamics Data Information System (CDDIS) archive of products derived from DORIS measurements consists of solutions provided by analysis centers of the International DORIS Service (IDS), as defined by the service’s analysis coordinator and approved by the Governing Board. Products derived from these DORIS data include precise satellite ephemerides, station positions and velocities (input to the derivation of the ITRF), time series of station coordinates, EOP (polar motion, length-of-day), and time derivatives of vertical Total Electron Content (TEC).

The format and time span of the products varies by product type. IDS analysis centers generate solutions of DORIS station positions on a weekly basis in SINEX (Software Independent Exchange) format. In addition, some ACs provide time series of station coordinate solutions in the STCD (STation Coordinate Difference) format; this format provides Cartesian and ellipsoid coordinate determinations and their formal errors allowing for the generation of point position time evolution plots. Other DORIS products include cumulative solutions of station velocities and positions at a reference epoch, geocenter determinations, EOPs, and satellite orbits. The DORIS data processing group generates ionospheric correction values from DORIS measurements.

Product Summary

• International DORIS Service Orbit Product
• Reference Frame Products
• Other Products

Product Formats

• SP3 and SP3c formats
• Software INdependent EXchange (SINEX) format

The archive of IDS products is organized in subdirectories by product type (e.g., time series of station positions, EOP values, orbits, etc.).

The starting directory for these files in the is: https://cddis.nasa.gov/archive/doris/products/

A complete description of directory structure and filename specifications is available from the IDS website: http://ids-doris.org/analysis-documents/struct-dc.html.