NAME

fste -- Transform Spacecraft coordinates to Equatorial coordinates.

USAGE

fste input_table

DESCRIPTION

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

PARAMETERS

input_table [file name template]

The table to have coordinates converted. This can be either an individual table or a list of tables.

(output_table) [file template]

If the new_table parameter is true, the user will be prompted to enter the output file name in which transformed tables are to be stored. Using a separate file will avoid overwriting the original data table. Output_table will accept a file name template when processing a list of data tables.

(new_table = no) [boolean]

Create a new output table? Prevents the original table from being overwritten.

(verbose = yes) [boolean]

Print transformed coordinates to the terminal screen?

EXAMPLES

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

BUGS

SEE ALSO