NAME:
  neosignal
 PURPOSE:   (one line only)
 DESCRIPTION:
 CATEGORY:
  Asteroids
 CALLING SEQUENCE:
  signal=neosignal(diam,albedo,sun,delta,phang)
 INPUTS:
  diam - Diameter of object in km
  albedo - geometric albedo
  sun  - Heliocentric distance (AU)
  delta - distance between observer and object (AU)
  phang - observer-object-Sun angle (phase angle) in radians
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  exptime - exposure time in seconds for integration (default=180)
 OUTPUTS:
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  This is not very generally written yet.  There are many hardcoded values
    such as the band pass of integration, telescope aperture, and more.
 PROCEDURE:
 MODIFICATION HISTORY:
  2016/01/21, Written by Marc W. Buie, Southwest Research Institute