Identifier   zodiacal

 Purpose      Compute zodiacal light model for an SWS AAR

 Synopsis     out = zodiacal(in, err_stat, /iras_offset,/aperture)

 Arguments    Name       I/O     Type:     Description:
              ----------------------------------------------------------
              in           I     AAR
              err_stat     I     Int       Error status: 1 for fatal, 0 otherwise
              out          O     AAR
              iras_offset  I     int       option to turn on the iras offsets
              aperture     I     int       option to convert output fluxes
                                           from Jy/ster to Jy.

 Returns      AAR with zodiacal light model

 Description  Shell which reads ra ,dec, ut from AAR header, reads wavelength
              array from AAR data part, calls ZODI_MODEL,
              puts the result in AAR corresponding to the input AAR, and
              converts the surface brightness into flux densities (Jy/ster).
              TBD: Convert to Jy within applicable SWS aperture 
              (using POINTTOEXT in /rev mode).
              Simple AAR arithmetics can then be used to subtract, add etc.
              the model from the original spectrum.

 Comment

 Example      struc_out = zodiacal(inaar, stat)

 Dependencies  CALLS: KWD_NOTSET, GET_HDRKEY, ZODI_MODEL
               CALLED FROM: IA, GUI

 Category     ISAP

 Filename     zodiacal.pro

 Author       I. Khan (irk@ipac.caltech.edu)

 Version      0.1

 History            17-07-95     Draft reqs DL      S. Lord/J. Mazz
              0.1   20-03-96     Design and code    I. Khan