NAME

fets -- Coordinate transformation from Equatorial to Spacecraft.

USAGE

fets input_table

DESCRIPTION

This filter searches data tables for equatorial rows, i.e., those rows where FRAME = E. When an equatorial row is located, the RA, DEC, and associated covariances are transformed to direction cosines in the S frame using quaternion multiplication. (The transforming quaternion is computed from the telescope pointing RAV1, DECV1, and ROLLV3.) If an error occurs in retreiving position information, the star is skipped. An error in retreiving covariances will cause only the covariance transformation to be skipped.

After each column is read, its value is set to INDEF. If an error occurs anywhere in the transformation, that column will contain the character S, regardless of whether the transformation was completed, or was incomplete.

The following columns are used by fets:

	INPUT		OUTPUT
	-----		------
	RA		X
	DEC		Y
	RA_RA		X,X
	DEC_DEC		Y,Y
	RA_DEC		X,Y
	FRAME		FRAME
	Q1,Q2,Q3,Q4

PARAMETERS

input_table [file name template]

The input can be either an individual data table, or a list of data tables to be transformed.

(output_table) [file name template]

If the parameter new_table is true, the user will be prompted for an output file name so that a new output data table can be created without corrupting the original data table. Output_table may be specified as a file template to process a list of data tables, each producing a separate output table file.

(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 equatorial to spacecraft coordinates.

	cl> fets intable

2. Convert a data table from equatorial to spacecraft coordinates, and create a new output table.

	cl> fets intable new_table+ output_table="outtable"

3. Convert all tables having the suffix .tab.

	cl> fets *.tab

BUGS

SEE ALSO