DORIS Data Format (April 1992) CNES Standard Exchange Format for Range-Rate Observations Columns Subset Description ------- ------ ------------------------------------------------------------- 1-7 Satellite identification 8-9 Measurement type 34 = USB doppler 38 = Tranet doppler 39 = DORIS doppler (up link, on board receiver) 10-11 Time system indicators 10 0 = ground received time 1 = satellite transponder/transmitter time 2 = ground transmitted time 3 = satellite received time 11 0 = UT0 1 = UT1 2 = UT2 3 = UTC (USNO) 4 = A-1 (USNO) 5 = TAI (BIH) 6 = A-S (Smithsonian) 7 = UTC (BIH) 8 = GPS 9 = station dependent correction required 12-16 Station ID 17-32 Time observation (beginning of count) 17-18 Year minus 1900 19-21 Day of year (January 1 = Day 1) 22-26 Seconds from midnight 27-32 Fractional part of seconds (microseconds) 33-35 Preprocessing indicators 33 0 = ionosphere correction applied 1 = ionosphere correctrion not applied 34 0 = troposphere correction applied 1 = troposphere correctrion not applied 35 0 = point consedered to be good 1 = point editted during pre-processing 2 = point editted during post-processing 36-45 Count interval in 0.1 microseconds 46-56 Range rate in micrometers/second 57-66 Meteorological data 57-60 Surface pressure (millibars) 61-63 Surface temperature (degress kelvin) 64-66 Relative humidity (percent) 67-72 Observation standard deviation (micrometers/second) 73-80 Ionospheric refraction correction (micrometers/second) 81-87 Tropospheric refraction correction (micrometers/second) 88-90 Meteorological data source, beacon type 91-96 Center of mass correction (micrometers/second) including both effects: satellite and beacon Specifications on the DORIS data format: 299792458. m/second should be used to convert frequency into meters. Time for DORIS = beginning of count interval Meteorological data source 1 = measured parameter 2 = pressure from a model 3 = temperature from a model 4 = pressure and temperature from a model 5 = humidity from a model 6 = pressure and humidity from a model 8 = temperature and humidity from a model 9 = pressure, temperature, and humidity from a model Beacon location 1 - Laboratory 2 - Field 3 - Other Beacon type 2 = tracking beacon Only data from tracking beacons are provided. Range rate has been commputed using the following equation: V(r) = c/f(bea)[(f(bea)-f(sat))-D/dt] with Vr = range rate m/s dt = count interval D = cycle count c = 299792458 m/s and our best estimate of the actual f(bea) (beacon frequency) and f(sat) (satellite frequeqency) ALL CORRECTIONS (IONOSPHERE, TROPOSPHERE, AND CENTER OF MASS) SHOULD BE ADDED TO OBSERVED VALUES OR SUBTRACTED FROM COMPUTED VALUES