M-AERI In Situ Scene Mirror Cleaning Procedure

Tools and Equipment Required

  • 3 mm Allen key
  • Spray bottle of distilled water
  • Spray bottle of 95% ethanol
  • Flashlight
  • Tray / rag / kimwipes to catch water and alcohol run-off
  • Absorbent wipes

General Notes

  • The mirror should be kept generally clean
  • The infrared is fortunately forgiving, so even a somewhat dirty looking mirror should be OK in the infrared
  • Anything opaque (dirt, mud, salt deposition, bird droppings) must be cleaned
  • Light smudging is OK
  • Unlike regular AERIs, mirror is not heated.  Do not clean with water when temperatures are below freezing.  Use only ethanol, or remove and clean/replace the mirror indoors
  • Do not ever touch the mirror surface.  Only the liquid jets should contact the surface
  • Ideally this procedure is done 15-20 minutes prior to 0000 UTC, when the last data will be discarded anyhow, and the instrument will automatically restart at 0000 UTC after the cleaning is complete
  • This procedure should be done in dry weather.  Be sure that the rain sensors will not get triggered during the procedure, so that the hatches stay open

Procedure

At the VM:

  1. Stop Ingest
    • In the black cygwin window, press <ctrl>+c multiple times
    • Close the cygwin windows
    • Close the FTSW windows
    • Ensure that all windows are closed and that ingest has been fully terminated
  2. Start FTSW
  3. In the Measurements tab, use the Mirror position dropdown menu to command the mirror to point to Zenith.  Use the dropdrop down menu to select Zenith even if it’s already selected.  Verify that the scene mirror angle is ~180°
  4. It will take 3 mins from starting FTSW for the hatches to open

At the M-AERI:

  1. Using a 3 mm Allen key, unscrew the two screws and remove the circular port cover visible on the side of the drum.  This will allow the cleaning liquid to drain out of the drum

At the VM:

  1. Select Custom in the Mirror position dropdown menu, and enter 75 for the Custom Mirror angle.  This commands the mirror to point to the side (and slightly downward for ease of access)

At the M-AERI:

  1. The scene mirror is now accessible on the side of the drum.  Clean the mirror using distilled water and 95% ethanol
    • Place a tray or absorbent material to collect the liquid that will be dripping out the bottom of the drum through the port that was opened
    • Use distilled water in a squirt bottle to spray a jet of water onto the mirror surface.  Apply repeatedly as needed.  Sometimes many applications will be necessary
    • Use ethanol for cleaning if needed
    • Finish off with ethanol to displace all of the water on the mirror surface.  The ethanol will quickly evaporate
    • Clean off the residual water around the area with absorbent wipes

At the VM:

  1. Command the mirror to point to Zenith. Verify that the scene mirror angle is ~180°

At the M-AERI:

  1. Replace the circular port cover on the side and secure with the two screws
    • Verify that the side port is being covered, not the sky port
    • Ensure that the two screws are flush with the drum surface and the drum is clear to rotate (any obstruction would prevent the drum from rotating and damage the motor)

At the VM:

  1. Close FTSW
  2. Restart Ingest.  Or wait until 0000 UTC for automatic reboot (if within 10 mins of 0000 UTC)
Mirror position
 Angle (approx)
Home (bottom) 0
Custom (horizon) 90
Zenith (sky) 180
HBB 240
ABB 300

Figure 1. M-AERI drum in cleaning position