NAME:
  rdoccsnr
 PURPOSE:   (one line only)
  Read an occultation SNR definition file and return a structure
 DESCRIPTION:
 CATEGORY:
  Occultations
 CALLING SEQUENCE:
  rdoccsnr,snr
 INPUTS:
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  FNCONFIG - name of configuration file to read,
                default='+support_files/snr.ini' which needs to be in your
                IDL_PATH (is including in my library).
                If you override, you can also put a + at the front of the
                string to also search your path for the file.  If you leave
                the '+' off, the file must be found as specfied.
 OUTPUTS:
  snr - anonymous structure with the SNR parameter information
 KEYWORD OUTPUT PARAMETERS:
 CONFIGURATION:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Southwest Research Institute, 2023/04/05