NAME:
  occsnr
 PURPOSE:   (one line only)
  Compute estimated SNR for an occultation with a specified system
 DESCRIPTION:
  This is mostly intend for occasional interactive calculations.
 CATEGORY:
  Occultations
 CALLING SEQUENCE:
  occsnr,system,exptime,gmag,gtarg,snr
 INPUTS:
  system - name of a standard system
  exptime - exposure time in seconds
  gmag   - G magnitude of occultaiton star
  gtarg  - G magnitude of the oculting body
 OPTIONAL INPUT PARAMETERS:
  SILENt - flag, if set will suppress all printed output
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  snr - Estimated signal to noise ratio
 KEYWORD OUTPUT PARAMETERS:
 CONFIGURATION:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Southwest Research Institute, 2024/11/09