rotation

The satellite rotation plot displays the first angle of rotation about the satellite pointing axis for which all of the on-board service systems and scientific equipment pointing restrictions are satisfied, as a function of time.

The rotation with respect to the earth frame of reference is displayed in green, while the rotation with respect to the celestial frame is shown in yellow. The celestial frame rotation is a graphical representation of the rotation angle displayed in the Solve display box on the initial uvplot screen. The rotation with respect to the earth is the angle required to rotate the z-axis of the satellite (see Figure 1) into the longitude equal to zero plane of the earth. The celestial rotation angle removes the effect of the rotation of the earth from the rotation angle and is the angle required to rotate the z-axis of the satellite into the plane of right ascension equal to zero. A schematic of the satellite's altitude is also displayed on this plot in grey.

 
Figure 1: The spacecraft coordinate frame

It is possible to write this rotation angle information to a file on disk by pressing the `f' key. The name of the file is then displayed in the lower right hand corner. The file name is generated from the first four letter of a string given in the uvplot.par file and the source right ascension and declination. It is possible to change the initial four letter string of the file name by pressing `l' and typing in the new character string. See Figure on p. .