This page is part of the ING manual WHT-INGRID-2:
INGRID IMPB Software Operations Manual
| Usage: | run int_time num_coavgs ["title"]
dark int_time num_coavgs ["title"] flat int_time num_coavgs ["title"] |
| Category: | Data Acquisition Command
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| Description: | These commands perform run, dark or flat observation
sequences.
The basic detector exposure sequence is a Multiple Non-Destructive Read (MNDR). This consists of a detector reset, Nr pre-integration reads, an integration period, then Nr post-integration reads. The pre-integration data and post-integration data are each summed and averaged two produce two distinct data sets. Normally these data sets are stored directly in the output file. However, if the coaverage option is specified then the MNDR sequence may be repeated and the resulting pre and post-integration data-sets averaged before saving in the final output file. Output files have names of the form 'r<n>.fit' where n is allocated from the central pool of run numbers used to tag observational data at the WHT. The file format is FITS compatible and contains complete header information (except where such information is unavailable due to a WHT subsystem (eg the TCS) being offline. The commands run, dark and flat differ only in the setting of the OBSTYPE header within the FITS output file. These are set to 'RUN', 'DARK' or 'FLAT' respectively. The number of reads in the MNDR cycle may be modified
using the numreads commands.
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| Arguments: | int_time is the MNDR integration time specified
in seconds to the nearest millisecond. The minimum integration time is
determined by the speed with which the SDSU Controller can scan the Hawaii
detector array (typically about 1.2 seconds).
num_coavgs specifies the number of coaverages in the observation sequence. num_coavgs should be a positive integer in the range 1 to 100. title is optional, but if specified provides
additional information which is recorded in the FITS headers. The title
string should be contained in double quotes if it is more than one word.
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| Examples: | run 10 1
- take a 10 second exposure with no coaveraging.
run 10 3 - takes three 10 second exposures in succession, then coaverages the data before storing in the output file. flat 1 1 "this is a test"
- takes a single 1 second exposure with the FITS OBJECT keyword set to
"this is a test". The OBSTYPE keyword will be set to 'FLAT'.
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