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Initial Engineering Tests

  Once the instrument control software has finished running up, the default `Set_observation' option is:

Object = Array Tests 
Obs_type = EXEC (ie highlighted)
which will run the EXEC called ARRAY_TESTS. This takes a standard set of 8 dark images which, when analysed, give an indication of how the array is currently performing (ie. dark current and readout noise). If these are not the defaults, enter them yourself. Hit PF1 to exit this menu. Upon exit, the contents of the EXEC ARRAY_TESTS will be loaded into the execution stack and displayed on the IRCAM parameter status screen. Move to the `Run' item to execute the EXEC ARRAY_TESTS by hitting Enter. Note down the start observation number of the ARRAY_TESTS EXEC. Let's call this start observation number N.

Once the EXEC has finished (a message will appear in the scroll region of the IRCAM instrument control SMS screen), the user should process the images acquired. (The very first ARRAY_TESTS almost always produces a larger than real dark current, so take two sets of ARRAY_TESTS, and only analyse the second.)

Within the IRCAM_CLRED window (see § 10 for how to start this up), type ARRAY_TESTS. Enter the start observation (N) of the ARRAY_TESTS data. The current STARE and ND_STARE readout noises and the current dark current will be estimated from the dataset and the values printed at the end of the analysis. Also given is an evaluation as to whether these values are in the valid operational range. An example of output expected is:

STARE    mode readout noise (e-) =  55.474
ND_STARE mode readout noise (e-) =  36.892
DARK CURRENT (e-/sec)            =  2.231

** STARE readout noise is nominal **
** ND_STARE readout noise is nominal **
** Dark current is nominal **

If these values are not nominal, then you need to check if the temperatures are too warm or if the chip is being properly read out (see §9).

Shaun Hughes
Thu Mar 14 14:48:38 GMT 1996