attcombine first=<filename> second=<filename> combined=<filename>


An attitude file represents a rotation as a function of time. Usually it is interpreted to mean a rotation with respect to a fixed coordinates system, such that it specifies a spacecraft attitude with respect to that coordinate system. However an attitude file can represent any arbitrary rotation. This tool takes two attitude files and merges them to produce a new attitude file which represents the result of applying first one rotation and then the other. It is primarily used with det2att to apply corrections to a spacecraft attitude.


first [filename]
Name of first input attitude file.

second [filename]
Name of second input attitude file.

combined [filename]
Name of output (combined) attitude file.

(alignfile = NONE) [filename]
Name of satellite alignment file or NONE or CALDB. If not NONE, a column POINTING will be created in the combined attitude file holding the RA, Dec, Roll corresponding to the combined output quaternion, and the POINTING column from the first input attitude file will be copied to the output attitude file as POINTING_ORIG.

(interpolation = LINEAR) [string]
Attitude interpolation method. Records in the combined output file have the same timestamps as those in the first input file. When the interpolation method is LINEAR, quaternions from the second input file with surrounding timestamps are linearly interpolated to the input time to arrive at the correction quaternion. When the interpolation method is CONSTANT, the quaternion from the second input file with the timestamp closest to the input time is applied. For times outside the bounds of the second input file, the correction quaternion is CONSTANT extrapolated.

(history = yes) [boolean]
Write parameter history?

(chatter = 1) [enumerated integer]
Standard HEAdas chatter parameter.





September 2005