[daip] No FQ table

[Eric Greisen]

Danielle Lucero wrote:
> Eric,
> 
> I am sorry that I am writing directly to you, but I can't seem to login 
> to the help desk.  I live in South Africa at the moment and the internet 
> is rubbish.  Anyway, I wrote you awhile back about problems I was having 
> with combining some WSRT data with some EVLA data.  
> 
> I have just realized that the problem may be the fact that when I load 
> the WSRT data in using FITLD no FQ table is produced.  Is there a way to 
> make an FQ table with a task similar to INDXR?   

Use the daip at nrao.edu e-mail if the helpdesk avenue does not work.  That 
way, if I am off on vacation, someone else will try to help.

If the WSRT data look like the EVLA data, then one could copy the FQ 
table from the similar EVLA file to the WSRT one.  You may have to fix 
up the data within the file.  Verb TABPUT allows you to change any value 
in the table in the data rows.  Verb PUTTHEAD allows you to change some 
of the header values.

The FQ tables has 6 columns:
FRQSEL  - integer = the FQ number (1 usually)
IF FREQ - double-precision = freq offset in Hz from the first IF
           usually the first value is 0 but these are added to the
           header freq to get the actual freq
CH WIDTH - channel separation for multi-channel data in Hz
TOTAL BANDWIDTH (mostly ignored)
SIDEBAND - integer set it 1
BANDCODE - character - blank is fine

note that columns 2-6 are arrays of size = the number of IFs (spectral 
windows).  When copying a table, that dimension must match.  that is the 
tricky part.  The header gives the 'NO_IF' keyword which will tell you 
the dimension and if you change that the file itself will be unusable.

Eric Greisen