[daip] some aips issues

[Eric Greisen]

Cao Hongmin wrote:
> Hi Eric,
> 
> How to properly undone the source position correction which has been 
> done by task "clcor" with adverb "ANTC"?
> I am confused with the "input" cl table version if want to undone the 
> correction.
> could the parameter setting as follows give the desired result ?
> 
> to correct:
> ...
> tget clcal
> default
> getn 1
> sources 'xxx'
> gainver 3
> gainuse 4
> opcode 'antc'
> clcorprm 0,0,0,0,0,-1.04,0
> go
> .....
> 
> to undone:
> ...
> tget clcal
> default
> getn 1
> sources 'xxx'
> gainver  4                           ! the same as the "output" cl table 
> as above.
> gainuse  5                        
> opcode 'antc'
> clcorprm 0,0,0,0,0,1.04,0    ! opposite sign
> go
> ...
> 
> it seems that the correction done like this is via changing the numbers 
> of the phase centre (or map centre) coordinates of the source, the 
> phase, the delay and the rate, while keeping the u,v,w coordinate values 
> unchanged (?).


This looks like what you need to do to undo the phase change.  CLCOR 
does not recompute u,v,w.  The task UVFIX does that.

Eric Greisen