saa_checker script documentation

1. Introduction:
   saa_checker.pl is a perl script called by "lr" which examines the mm*.sum file that is bundled in the backstop tar file. This file contains Chandra maneuver and orientation information which includes the solar array angle (saa) for each observation. If an SAA is below 60 degrees, this exacerbates thermal heating of the ACIS Power Supply and Mechanism Controller (PSMC). If an SAA is above 135 degrees, this increases thermal heating of the ACIS DEA and focal plane. This script provides the ACIS load reviewer and team with a warning for potential problem observations by listing the angle and duration of observation.
2. Execution dependancies:
   Script is automatically executed from within "lr" but can be run independently if need be. In this case, execution would require that the load review products are readily available, specifically the mm*.sum file that is included in the backstop tar file for each load.
3. Script dependancies:
   

   Script is executed from lr

   Scripts that depend on the outputs

   The lr script does a "more" on the output of saa_checker (saa_check.txt) to display to the user.

4. Code Location and execution
5. Problems and Issues
6. Notes