The Satellite Parameter Files

Contained in Tables 6 and 7 are the parameters describing the two spacecraft Radioastron and VSOP. These parameter files allow each spacecraft or any other to be configured separately such that ground will be able to handle any last minute changes to orbital or satellite parameters.

The first lines in Tables 6 and 7 contain the initial orbital parameters in the order: semi-major axis, eccentricity, inclination, longitude of ascending node, argument of perigee and the mean anomaly. Here, the semi-major axis value must be in meters. The next line is the reference date of these orbital elements in dd mm yy format. Following this the Universal time of the mean anomaly in hh mm ss format. Then the satellite system temperatures at each of the four frequencies accompanied by the corresponding antenna efficiencies.

The next line contains the minimum angles in degrees between these vectors and a vector pointing from the satellite to the sun, moon, and earth, respectively.

The telemetry angle limit is the maximum angle in degrees between the high gain downlink antenna and the negative x-axis of the spacecraft, assuming that the satellite is free to rotate about this axis. Since the antenna is free to rotate in a hemisphere and the axis of this hemisphere is the angular offset of the high gain antenna from the negative x-axis, which is 30, the telemetry angle limit for Radioastron is 120, that is 90 + 30. Following is the vector in the satellite reference frame for the axis of the high gain antenna.

  
Table 6: Radioast.par file used in uvplot, ground and allsky

  
Table 7: VSOP.par file used in uvplot, ground and allsky