fste -- Transform Spacecraft coordinates to Equatorial coordinates.
This filter will convert Spacecraft coordinates to Equatorial coordinates. The filter searches data tables, row by row, looking for rows where FRAME=S, indicating a Spacecraft coordinate. When a Spacecraft coordinate is found, the X, Y, and associated covariances are converted to Equatorial coordinates using quaternion multiplication. (The transforming quaternion is computed using data columns Q1, Q2, Q3, and Q4, where Q4 is the scalar part of the quaternion). If an error occurs in retreiving position information, the star is skipped. An error in retreiving covariances will only cause the covariance transformation to be skipped.
Each column is read and its value set to INDEF. If an error occurs anywhere in the transformation, the row is skipped and the values remain INDEF. The FRAME column is set to E regardless of whether the transformation was completed, or was incomplete. The RA and DEC columns will contain positions in decimal degrees.
The following columns are used by fste:
INPUT OUTPUT ----- ------ X RA Y DEC X_X RA_RA Y_Y DEC_DEC X_Y RA_DEC FRAME FRAME Q1,Q2,Q3,Q4 Q1,Q2,Q3,Q4
1. Convert a data table from Spacecraft to Equatorial coordinates.
cl> fste intable
2. Convert a data table from Spacecraft to Equatorial coordinates, and create a new output table.
cl> fste intable new_table+ output_table="outtable"
3. Transform coordinates in all tables having the suffix .tab.
cl> fste *.tab