Last updated on 2013/05/22

The present DORIS data formats (1.0, 2.1, 2.2) only includes the observation made on the 2 GHz  channel. 
The ionospheric effect on the Doppler count, deduced from the 400 MHz channel, is given as a correction 
and cannot be re-estimated using the data files.

The SOD, “Service d'Orbitographie DORIS” in CNES, routinely generates and delivers the DORIS data files 
to the IDS Data Centers. 
For ionospheric studies, SOD proposes some specific files. They contain the two channel observations 
and additional parameters such as elevation angle of the satellite, local time that allow quick analysis.

Ionospheric files are available for the satellites:
SPOT2 (2001/01/01-2009/07/29)
SPOT4 (from 2001/01/01)
SPOT5 (from 2002/05/04)
ENVISAT (2009/01/18-2009/09/30)
JASON-1 (from 2002/08/19)
TOPEX-POSEIDON (2001/01/01-2004/10/31)

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Contact : Pascale.Ferrage@cnes.fr, ids.central.bureau@ids-doris.org
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File description
------------------- 
cccsssVV.YYDDD.iono.Z

Where
      ccc  = center three-character acronym 
      sss  = satellite three-character abbreviation
            Spot2 : sp2           Topex/Poseidon : top
            Spot3 : sp3           Jason 1 :        ja1
            Spot4 : sp4           Envisat :        en1
            Spot5 : sp5           All satellites:  zzz
      VV   = version number of the solution
      YY   = last two digits of year
      DDD  = three-digit day of year
      iono = fixed part (refers to the content)

The format is :
- for the header (for each satellite pass over a beacon) : 
satellite, beacon mnemo, number of observations, max of satellite pass elevation (°), 
local time (deg), meteorological data : Pressure (mb), T (deg), Humidity (%)  
 ex : SPOT2 SALB   27  57.954  22.6091012 21 68

- for the data :
CNES julian date, second in the day of the observation (TAI),
elimination criteria,
count interval (2 GHz channel) in second,
count interval (400 Hz channel) in second,
Tropospheric correction (2 GHz channel) in cycle,
Tropospheric correction (400 MHz channel) in cycle,
Ionospheric correction (2 GHz channel) in cycle,
Ionospheric correction (400 GHz channel) in cycle,
Elevation angle (°), Azimuth (°), Station-satellite distance (m),
Acquisition mode, 
Received power level (400 Mhz), Received power level (2 Ghz),
Ponderation (0 if eliminated or 1),
Doppler count (400 Mhz), Doppler count (2 Ghz) in cycle.

Ex :
 19366   229.99474600 -502 8.9999978 9.0000031    4.888103129054    0.963218126512   -0.576815438149   -2.927203578642 12.3947180.68132307665.4170-116-125 0.012014401512927
 
format (i6,f15.8,i5,2f10.7,4f18.12,2f8.4,f11.3,i1,2i4,f4.1,2i7)