2.2 Reading the data from CD-ROM and having a quick-look at the data

The most important dataset to read off CD-ROM is the Auto-Analysis Results (AAR)  file. Select the SWAA FITS file of the observation you want and read that off the CD-ROM into your environment. Then you should read the FITS file into your data reduction package using your local commands.

MIDAS

For MIDAS users the commands:

indisk/fits <file.fits> file
print/tab file file.dat

will output the fits file as plain ASCII which can then be imported into most packages (thanks to Paul Crowther of UCL).

IDL

To read a the FITS files in using IDL:

data = readfits( <file.fits>, header, exten_no = 1 )

reads in a data array. If ;SPMlt;file.fits;SPMgt; was an AAR file it would have a length of 52 * length of SWAA file + header.

print, tbget( header, data, 1, 0)

for an AAR would print the first wavelength.

print, tbget( header, data, 1, 1)

for an AAR would print the second wavelength.

print, tbget( header, data, 2, 1012)

for an AAR would print the 1013th flux.

The header variable will tell you in what order variables appear in the data array, as will the various IDUMS. For AAR the order is given in section 9.4.1 and is:

'SWAAWAVE'
'SWAAFLUX'
'SWAASTDV'
'SWAATINT'
'SWAADETN'
'SWAAITK '
'SWAAUTK '
'SWAARPID'
'SWAASPAR'
'SWAALINE'
'SWAASDIR'
'SWAASCNT'
'SWAASTAT'
'SWAAFLAG'