20200123

Dome/bay light-tightness check

Some time at night when we are closed for weather, please attempt the following test to evaluate possible light leaks into the dome from the receiving bay. We will use the LRS2 IFU since its analysis is simpler than VIRUS and has a wider wavelength range.

• The dome must be closed, all louvres closed, GTAG door closed, no light sources in the dome.
• Run this test with tracker at center, with the structure at three different azimuths:
  • structure pointing toward the south-east (Az=135), right at the bay door
  • structure pointing toward the south-west (Az=225), orthogonal to bay door
  • structure pointing toward the north-west (Az=315), opposite of the bay door
• At each azimuth, try four different lighting configurations:
  • all lights in bay OFF, all doors closed
  • stairwell light in bay ON, all doors closed
  • stairwell light ON, door at top of stairs OPEN, fluorescent lights in control room ON
  • receiving bay lights ON
• The test procedure itself is:
  • make sure the FCU head is retracted
  • make sure the ACQ mirror is retracted (and PV mirror retracted too)
  • open the PFIP shutter
  • take a 300s engineering exposure (NOT a "dark"), label it with azimuth/light conditions

Finally, turn off all lights, and take a 300s "dark" frame (FCU head in, shutter closed), which will be used as a baseline.

This should require 13 exposures, and probably take about 1.5h to complete.