[daip] UVFITS format with two IFs

[Stéphane Guilloteau]

Dear AIPS expert

   I have a UVFITS file created by AIPS, which contains full 
polarization observations in continuum of one source (already 
calibrated). The data has two IFs. How do I derive the observation 
frequencies for the two IFs from the FITS header ?

    Cheers

       Stephane

The FITS header looks like this:
$ more MWC480_X_UVCAL.FITS
SIMPLE  =                    T /
BITPIX  =                  -32 /
NAXIS   =                    7 /
NAXIS1  =                    0 /No standard image just group
NAXIS2  =                    3 /
NAXIS3  =                    4 /
NAXIS4  =                    1 /
NAXIS5  =                    2 /
NAXIS6  =                    1 /
NAXIS7  =                    1 /
EXTEND  =                    T /This is the antenna file
BLOCKED =                    T /Tape may be blocked
OBJECT  = 'MWC480  '           /Source name
TELESCOP= 'VLA     '           /
INSTRUME= 'VLA     '           /
OBSERVER= 'AP492   '           /
DATE-OBS= '2005-07-17'         /Obs start date YYYY-MM-DD
DATE-MAP= '2007-06-21'         /Last processing date YYYY-MM-DD
BSCALE  =    1.00000000000E+00 /REAL = TAPE * BSCALE + BZERO
BZERO   =    0.00000000000E+00 /
BUNIT   = 'UNCALIB '           /Units of flux
EPOCH   =      2.000000000E+03 /Epoch of RA DEC
VELREF  =                    3 />256 RADIO, 1 LSR 2 HEL 3 OBS
OBSRA   =    7.46927916667E+01 /Antenna pointing RA
OBSDEC  =    2.98436111111E+01 /Antenna pointing DEC
CTYPE2  = 'COMPLEX '           /1=real,2=imag,3=weight
CRVAL2  =    1.00000000000E+00 /
CDELT2  =      1.000000000E+00 /
CRPIX2  =      1.000000000E+00 /
CROTA2  =      0.000000000E+00 /
CTYPE3  = 'STOKES  '           /1=I, 2=Q, 3=U, 4=V
CRVAL3  =    1.00000000000E+00 /
CDELT3  =      1.000000000E+00 /
CRPIX3  =      1.000000000E+00 /
CROTA3  =      0.000000000E+00 /
CTYPE4  = 'FREQ    '           /Frequency in Hz.
CRVAL4  =    8.43510000000E+09 /
CDELT4  =      5.000000000E+07 /
CRPIX4  =      1.000000000E+00 /
CROTA4  =      0.000000000E+00 /
CTYPE5  = 'IF      '           /Freq. group no. in CH table
CRVAL5  =    1.00000000000E+00 /
CDELT5  =      1.000000000E+00 /
CRPIX5  =      1.000000000E+00 /
CROTA5  =      0.000000000E+00 /
CTYPE6  = 'RA      '           /Right Ascension in deg.
CRVAL6  =    7.46927916667E+01 /
CDELT6  =      1.000000000E+00 /
CRPIX6  =      1.000000000E+00 /
CROTA6  =      0.000000000E+00 /
CTYPE7  = 'DEC     '           /Declination in deg.

-- 
Dr. Stephane Guilloteau
Laboratoire d'Astrophysique de Bordeaux
2 rue de l'Observatoire, BP 89
 F-33270 Floirac, France

 Tel: +33 557 77 61 68
 Fax: +33 557 77 61 10
 Mob: +33 683 84 66 70