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Shutter Error Analysis

The data below is generated using the exposures noted to have experienced a shutter error in the electronic logbook.
Shutter errors likely caused by software were not included.

Shutter Errors

Until recently (late December 2013) shutter errors were not recorded in the DECam database so we had to scan the logbook to get a list of shutter errors since October.
We found 36 occurrences in about 20,000 on sky exposures (we excluded calibration frame for this study)

Position

There does not appear to be any correlation between shutter errors and the telescope position.
The left plot shows HA and Declination values for exposures with a shutter error. The right plot shows the same, but with all exposures September through December.
The second plot is of just the month of October, for a clearer comparison.

Temperature

There does not appear to be any correlation between temperature and the shutter errors.

The left plots below show the distribution of temperatures for shutter errors. The right plots below show the distribution of temperatures for all exposures September through December.

Using uts_temp (upper truss south side temperature) as temperature measurement:
Using domelow as temperature measurement: