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Doppler Orbitography by Radiopositioning Integrated on Satellite (DORIS) is a dual-frequency Doppler system consisting of a receiver flying aboard a satellite and a globally distributed network of ground beacons. The DORIS receiver on-board the orbiting satellite tracks the dual-frequency radio signals transmitted by the network of ground beacons and generates the DORIS data. A measurement is made of either the Doppler shift or absolute phase as the satellite’s orbit moves over the ground-based beacon.

DORIS has been included as a host experiment on various space missions. Current missions with on-board DORIS receivers are CryoSat-2, HY-2A, Jason-3, Sentinel-6 Michael Freilich, and Satellite for ARgos and ALtiKa (SARAL). Legacy missions include TOPEX/Poseidon, Jason-1 and -2/OSTM, Envisat, and SPOT-4 and -5.

Unlike many other navigation systems, DORIS is based on an uplink device. The receivers are on board the satellite while the transmitters are on the ground. This creates a centralized system in which the complete set of observations is downloaded by the satellite to the ground center, from where they are distributed after editing and processing.

DORIS Overview

DORIS Data and Product Archive

NASA’s Crustal Dynamics Data Information System (CDDIS) serves as a global data center for the International DORIS Service (IDS) by holding DORIS data and products in their archive. DORIS data in RINEX format are submitted to CDDIS daily with a one-day delay. DORIS data in the original format are also supplied to the data center in multi-day files, corresponding to the mission’s data processing arc, and are forwarded approximately 20 days after the end of the last observation day contained in the file.

DORIS data records contain a time-tagged range-rate measurement with associated ancillary information. The data records also contain information about any corrections that may have been applied during the processing phase, such as for the ionosphere, troposphere, and satellite center of mass, among others. Furthermore, meteorological measurements (e.g., temperature, relative humidity, ground pressure) recorded by instruments co-located with the ground-based beacons are included with the DORIS data and can be used to determine the tropospheric correction.

Learn more about DORIS data and product holdings.

The Doppler Orbitography by Radiopositioning Integrated on Satellite (DORIS) was developed by the Centre National d'Etudes Spatiales (CNES) with the cooperation of Groupe de Recherche en Géodésie Spatiale (GRGS) and the Institut Géographique National (IGN). The system was developed to provide precise orbit determination and high accuracy location of ground beacons for point positioning. An accurate measurement is made of the Doppler shift on radiofrequency signals emitted by the ground beacons and received on the spacecraft.

In addition to POD applications some of the scientific uses of DORIS data include:

  • Realization of global accessibility to and the improvement of the International Terrestrial Reference Frame ( ITRF)
  • Monitoring deformations of the solid Earth
  • Monitoring crustal deformation at tide gauges
  • Monitoring variations in the hydrosphere (sea level, ice-sheets, etc.)
  • Orbit determination for scientific satellites

The DORIS permanent tracking network includes 58 permanent beacons with an even geographical distribution; this network is utilized by all missions with on-board DORIS receivers. Installation and maintenance of this ground network is performed by IGN. This map of the DORIS network is also available in PDF form.

International DORIS Service
CDDIS serves as a Global Data Center for the International DORIS Service (IDS), supporting the archive and distribution of data from the global DORIS beacon network and the IDS products derived from these data.
Learn more about the IDS
A graphic of Earth with white nodes connecting tan continents is beneath a yellow arc. Below are the letters IDS.

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