
Dear reader,

at the web page https://rsdb.obs-nancay.fr/#!/documentation I have found
http://rsdb.obs-nancay.fr/public/Doc/raworfees.pro with the IDL routine
raworfees.pro for reading ORFEUS data. I use it in my software.

To run the raworfees.pro you need the SSW including the mrdfits.pro which
is located in SSW/gen/idl/fits/mrdfits.pro or also in
SSW/gen/idl_libs/astron/fits/mrdfits.pro .

As the ORFEUS data are not equidistant in frequency I have made a soft
for converting the intensities to the equidistant frequency axis (what
we needed for our purposes). This soft uses a nice procedure
(Intep - an Effective Interpolation Subroutine, Hill, G., Publications
of the Dominion Astrophysical Observatory, Vol. 16, NO. 6, P. 67, 1982,
https://ui.adsabs.harvard.edu/abs/1982PDAO...16...67H/abstract).

In the ZIP file you will find the IDL procedures:

intep_gh_jr.pro - INTEP routine
orfees_fits_to_XDR_and_corrections.pro - main code for ORFEUS actions 
       (reading fits, equdistancing the f-axis, storing the IDL XDR file)
raworfees.pro  - original procedure to read ORFEUS FITS data files
read_orfees_radio_fts_file.pro - my routine for calling raworfees.pro

int_orf20220402_132000_1.fts - original ORFEUS FITS file
int_orf20220402_132000_1.xdr - resulting IDL XDR file

THE ADVICED PROCEDURE FOR FITS->XDR CONVERSION:

- put all PROs and ORFEES FIST file in one directory
- set this directory as working directory in your shell (unix)
- start SSW
- .r orfees_fits_to_XDR_and_corrections.pro
  - input: ORFEES FITS file
  - output: the equidistant radiospectrum data in th IDL XDR file format

IDL USAGE OF THE ORFEES XDR DATA FILE:

- restore,orfees_file_name+.'xdr',/ver

- list of stored variables:
  ' AVAILABLE VARIABLES = '

  ' DATA        - 2D (time,frequency) radio intesities'
  ' TIME_SS     - temporal axis [seconds]'
  ' TIME_HH     - tmeporal axis UTC [HH.HH]'
  ' FREQUENCIES - frequency axis [MHz]'
  ' T1,T2       - temporal axis - first value [HH.HH], last value[HH.HH]'
  ' NT,DT       - temporal axis - number of values, temporal step [s]'
  ' F1,F2       - frequency axis- first and last values [MHz], f1<f2 '
  ' DF,NF       - frequency axis- number of values, freq. step [MHz]'
  ' DATE        - DATE [YYYYMMDD]'
  ' TIME1       - time start - string [HH:MM:SS]' 
  ' TIME2       - time end   - string [HH:MM:SS]'
  ' T1_FOD      - time start - fraction of day - float'
  ' T2_FOD      - time start - fraction of day - float'
  ' N_MIN       - time interval - number of minutes - integer'
  ' HH1,MM1,SS1 - time start - hour, minute, second - strings'
  ' HH2,MM2,SS2 - time end   - hour, minute, second - strings'
  ' STATION     - string = ORFEES'

With the best wishes

Jan Rybak (rybak@astro.sk), 2023/02/06
