fixplanets – Changes FIELD and SOURCE table entries based on user-provided direction or POINTING table, optionally fixes the UVW coordinates – editing, maninpulation, calibration task

Description

This task’s main purpose is to correct observations which were performed with correct pointing and correlation but for which incorrect direction information was entered in the FIELD and SOURCE table of the MS. If you actually want to change the phase center of the visibilties in an MS, you should use task fixvis.

Parameters

Title

Parameter	Default	Description
vis	''	Name of input visibility file
field	[ ]	Select field using field id(s) or field name(s)
fixuvw	False	Recalculate Fourier-plane u,v,w coordinates
direction	''	If set, do not use pointing table but set direction to this value
refant	int(0)	Reference antenna name(s)
reftime	'first'	If using pointing table information, use it from this timestamp

Parameter Explanations

vis

''

Name of input visibility file

Default: none

Example: vis=’ngc5921.ms’

field

[ ]

Select field using field id(s) or field name(s)

Default: ‘’ (all fields)

Use ‘go listobs’ to obtain the list id’s or names. If field string is a non-negative integer, it is assumed a field index, otherwise, it is assumed a field name.

Examples: field=’0~2’; field ids 0,1,2 field=’0,4,5~7’; field ids 0,4,5,6,7 field=’3C286,3C295’; field named 3C286 and 3C295 field = ‘3,4C*’; field id 3, all names starting with 4C

fixuvw

False

Recalculate Fourier-plane u,v,w coordinates?

Default: False Options: False|True

direction

''

If set, do not use pointing table but set direction to this value

Default: ‘’ (use pointing table)

Example: ‘J2000 19h30m00 -40d00m00’

The direction can either be given explicitly or as the path to a JPL Horizons ephemeris. Alternatively, the ephemeris table can also be provided as mime format file. For more information, see the task pages of fixplanets in CASA Docs (https://casa.nrao.edu/casadocs/).

refant

int(0)

Reference antenna name(s); a prioritized list may be specified

Default: 0 (antenna ID 0)

Examples: refant=’4’ (antenna with index 4) refant=’VA04’ (VLA antenna #4) refant=’EA02,EA23,EA13’ (EVLA antenna EA02, use EA23 and EA13 as alternates if/when EA02 drops out)

Use taskname=listobs for antenna listing

reftime

'first'

If using pointing table information, use it from this timestamp

Default: ‘first’

Examples: * ‘median’ will use the median timestamp for

the given field using only the unflagged maintable rows

• ‘2012/07/11/08:41:32’ will use the given timestamp (must be within the observaton time)