multrun Command


This page is part of the ING manual WHT-INGRID-2: INGRID IMPB Software Operations Manual


 
Usage: multrun num_runs int_time num_coavgs ["title"]
 
Category: Data Acquisition Command
 
Description: This command is exactly the same as run except that:
  • the run sequence is repeated a multiple number of times, generating multiple output files.
  • the INGIM and INGNM headers are modified to reflect the index of the run and the total number of runs in the sequence respectively.
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 number of reads in each MNDR cycle may be modified using the numreads commands. 
 
Arguments: num_runs specifies the number of times the basic run sequence is to be repeated. Should be a positive integer in the range 1 to 100.

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.
 
Examples: multrun 5 10 1 - take five 10 second exposures with no coaveraging.