CHANGE_POINTING - Change the pointing corrections to map data

Description:

This application is used to change the pointing corrections to map data.

If the observing mode of the input datafile is `MAP' the application will search for pointing corrections in the file and, if it finds any, report them. You will be asked if you wish to change the pointing correction data in the file. `No' will result in the data remaining unaltered, `yes' will then ask you for the time of the pointing offset (LST in hh mm ss.ss format) and the azimuth and elevation correction (in arcseconds) that would have to be added to the observation position to correct the pointing at that time. If you supply no data the existing pointing corrections will be removed. Corrections will be requested until a negative number is given for the local sidereal time.

Usage:

change_pointing in change_point

Parameters:

CHANGE_POINT = CHAR (Read)

If true you will be prompted for pointing corrections otherwise the program will exit after listing the current pointing corrections.

IN = NDF (Read)

Name of NDF to change.

MSG_FILTER = CHAR (Read)

Message filter level. Allowed values are QUIET, NORM and VERB. Default is NORM.

POINT_DAZ = REAL (Read)

The Azimuth pointing correction (arcsec).

POINT_DEL = REAL (Read)

The elevation pointing correction (arcsec).

POINT_LST = CHAR (Read)

The sidereal time of the pointing correction. Pointing corrections are asked for repeatedly until a NULL (!) or negative value are given for POINT_LST.

Notes:

• Pointing corrections are erased when new items are written.

• Pointing corrections can be removed completely by issuing null (!) in response to POINT_LST when first prompted. (ie pointing corrections are removed if no corrections are given)

• Use ABORT (!!) if you don't want to change the pointing corrections once you have started entering values.

• Pointing corrections must be given in LST order.

Related Application

SURF: rebin