INGRID overheads

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INGRID overheads

Readout times

Window size	Fast readout mode	Slow readout mode

128 x 128	0.083 s	0.097 s
256 x 256	0.176 s	0.242 s
full frame	0.505 s	0.755 s

Single cycle time

The single cycle time is needed to complete a single observation of the minimum exposure time without windowing. This includes all overheads such as readout, collecting headers, archiving etc. For INGRID it varies between 3.7s and 4.4s, i.e. run ingrid 0 takes this amount of time to give you the prompt back.

Filter changes

		Final position
		K	Ks	H	J	blank

Initial position	K	-	20	38	55	100
	Ks	unknown	-	47	64	unknown
	H	37	46	-	38	82
	J	58	64	38	-	66
	blank	99	108	82	62	-

The table shows the seconds needed to change the INGRID filters using the command
filter ingrid <filter name>.
Note that the filter movements in some cases imply movements of more than one filter wheel, since each filter movement is tied to other filter and/or pupil movements (see the filter/pupil combinations). In general, the filter change overheads are rather symmetrical, i.e. the time to switch from one filter to the next and back is about the same.


	Last Updated: 10 May 2004 Mischa Schirmer ( )