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.

CHANGE_POINT = CHAR (Read)

IN = NDF (Read)

MSG_FILTER = CHAR (Read)

POINT_DAZ = REAL (Read)

POINT_DEL = REAL (Read)

POINT_LST = CHAR (Read)

• 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.