0.9-m Overhead Times

Timing Overhead for Various Actions at the 0.9-m

There are two sets of times listed below, LIGHTNING and HUMAN.  The LIGHTNING case assumes that everything goes absolutely perfectly, with observer reaction time an absolute minimum.  This does not occur in real life.  The HUMAN overhead is the one that should be adopted for all service observing programs.

  LIGHTNING HUMAN
Slew/Target Acquisition 3 min 5 min (variable)
Change Directory/File Name 1 min 1 min
Change Chip Setup 1 min 2 min
Change Tracking (non-sidereal) 1 min 2 min
Focus Frame 3 min 6 min
Chip Readout    
  Full Chip/Four Amps 0.8 min 0.8 min
  Full Chip/One Amp 3 min 3 min
  Quarter Chip/Four Amps 0.3 min 0.3 min
  Quarter Chip/One Amp 0.8 min 0.8 min


Example

You have a short service program that is inserted into a longer program scheduled for the same night.  You want to use a different chip setup, non-sidereal tracking, and a single 300 second integration.  The required time is:
 

Slew/Target Acqusition 5 min
Change Directory/File Name 1 min
Change Chip Setup 2 min
Change Tracking (non-sidereal) 2 min
Focus Frame 6 min
Chip Readout = Full Chip/Four Amps 0.8 min
Integration Time 5 min
   
Change Directory/File Name BACK 1 min
Change Chip Setup BACK 2 min
Change Tracking (non-sidereal) BACK 0 min (flip switch)
   
Total Time for Observation 24.8 min