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What's DORIS?

See the official website.

 

What kind of information may be found on which center?

IDS has three data/information centers:

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What is the nominal data delivery time?

DORIS measurement files are usually delivered to the Data Centers with the following times:
  • SPOT5: 4 weeks
  • JASON2: 4 weeks
  • CRYOSAT2: 4 weeks
  • HY-2A: 4 weeks
  • SARAL: 4 weeks

Delivery times are linked to processing time of the precise orbit ephemeris (POE), and in particular to the collect of precise measurement of the solar activity and Earth orientation parameters.
Delays may temporarily increase due to manpower availability.

Some subsets of data were re-delivered to the IDS Data Centers to include improved corrections. These new deliveries with an incremented version number are documented in DORISmails.

 

Stations Network

Permanent sites, colocations
This global map shows the current network.
General information (Site log)
For general information such as site description, local ties, beacon identification, go to the Site log pages.
ITRF2008 coordinates and velocities
They may be found directly in sinex format for the DORIS network on the dedicated ITRF ftp site.
See also the complete ITRF2008 for all space geodesy techniques.
Ground antennas
There are two types of ground antennas. See the geometrical caracteristics and examples of the two types of antennas: Galapagos (Alcatel), Santa Cruz (Starec). 
Satellite visibility
The maps for the Envisat and Jason satellite orbit show the visibility circle around each station with a given cut-off angle over the horizon.
Host agencies
The network of DORIS permanent stations is one of the essential component of the system. It is in operation for more than ten years. The host agencies play a key role for the maintenance of the stations with an onsite support.
Maintenance, renovation
The IGN/SIMB is in charge of the maintenance of the network.
Contact
Bruno Garayt from IGN is responsible for the DORIS network. 
The DOMES Numbering System
DOMES (Directory Of MERIT Sites) is a numbering system for the space geodetic sites. It was designed at the start of the MERIT (Monitoring of Earth Rotation and Intercomparison of the Techniques of Observation and Analysis) campaign in early 80s in order to give an unambiguous identifier to all instrument reference points and markers involved in this MERIT campaign.
The first publication of this information was done in a catalogue published by the Bureau International de l'Heure (BIH) and entitled "Directory Of MERIT Sites", hence DOMES. The BIH, together with the IGN group, was acting as MERIT coordinating center.
Since the official start of IERS in 1988, the TRF section of the IERS/CB continued this task for all ITRF contributing stations.

More details about the DOMES Numbering System can be found at http://itrf.ensg.ign.fr/domes_desc.php.
For information about the MERIT project, see http://www.to.astro.it/sarasso/MERIT.htm.
About IDs and DOMES of Master Beacons
Except for the Master Beacons (MB), the DOMES number of a DORIS station is always associated to a single ID.
When the antenna is changed or moved, a new reference point is defined and a new DOMES number and a new ID are given, even if the tie with respect to the previous reference point is null. When the beacon is changed, DOMES number and ID are not changed.

For the Master Beacons (Kourou, Toulouse, Hartebeesthoek and Papeete), it occurred that IDs were changed but the DOMES number was kept unchanged. These are the following cases for which one DOMES number is associated to two different IDs.
Kourou:                 2 IDs, KRUB and KRVB, but 1 single DOMES number 97301S004
Toulouse:             2 IDs, TLHA and TLIA, but 1 single DOMES number 10003S003
Hartebeesthoek: 2 IDs, HBKB and HBLB, but 1 single DOMES number 30302S006 (see also DORISmail No 474)
Papeete:               2 IDs, PATB and PAUB, but 1 single DOMES number 92201S010 (see also DORISmail No 632)
The IDs were changed either when the nominal MB was switched to the redundant MB or vice versa (Kourou, Toulouse) or when the standard orbit determination beacon was upgraded to a MB (Hartebeesthoek, Papeete). The DOMES number was not changed because there was no physical change on the antenna.?
Frequency shift of the 3rd DORIS beacon generation
The transmitted frequencies of the 3rd DORIS beacon generation may be shifted with respect to the nominal DORIS frequencies to avoid jamming with other DORIS stations in the vicinity. This function is only used when two channels are available on the DORIS instrument that is to say with SPOT5, JASON, ENVISAT and the soon CRYOSAT. See a detailed description and the history list of the stations using the shifted mode.
About the 4-letter code
The 4th character of the ground beacon 4-letter code (sometimes also referred to as mnemonic) identifies the type of antenna:
letter 'A' for the ALCATEL type (last antenna removed in 2007) (eg. ROTA) 
letter 'B' for the STAREC type, former error budget (installation before October 2014) (eg. ROVB)
letter 'C' for the STAREC type, improved error budget (installed from October 2014) (eg. ROWC)
The third type (4-letter code ending with letter C) has been introduced to clearly indicate sites equipped with DORIS STAREC antenna produced since 2014 July with a consolidated process. This means that they have the same characteristics than the previously deployed STAREC antenna, but with an improved error budget. In other words, there is no design difference between type “B” and type “C”, they have the same specifications. The distance between the 2 Ghz phase center and the DORIS reference plan stays unchanged (see ftp://ftp.ids-doris.org/pub/ids/stations/antennas.pdf).
The type “C” antennas will progressively replace the type “B” antennas. The first four are PDNC (Ponta Delgada), OWEC (Owenga), ROWC (Rothera), KEUC (Kerguelen).
More about the consolidated process
In the frame of permanent performance validation and improvement of the DORIS system, a characterization of DORIS STAREC ground antennae was performed over years 2013 and 2014.This leads to a new phase law correction that was provided. During this characterization, it appeared that there was a dispersion in mechanic mounting of STAREC antennae. This dispersion implies an increase of the error budget link to the phase law correction. To improve the error budget, a work has been performed with the antenna manufacturer. The manufacturing process has been consolidated and thus, the budget error has been improved. (Cf. C. Tourain's presentation at IDS Workshop 2014)

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