slotutcfix

Name

slotreadtimefix – Correct UTC times in slotmode data headers

Usage

slotreadtimefix images outimages outpref (clobber) (logfile) (verbose)

Parameters

images

String. List of images to reduce. Data can be provided as a comma-delineated list, or a string with a wildcard (e.g. ‘images=S20061210*.fits’), or a foreign file containing an ascii list of image filenames. For ascii list option, the filename containing the list must be provided preceded by a ‘@’ character, e.g. 'images=@listoffiles.lis‘. Note that SLOT mode fits files often contain more than one exposed frame.

outimage

String. A list of images. Data can be provided as a comma-separated list, or a string with a wildcard (e.g. ‘outimages=rS20061210*.fits’), or a foreign file containing an ascii list of image filenames. For ascii list option, the filename containing the list must be provided preceded by a ‘@’ character, e.g. 'outimages=@listoffiles.lis‘. This list must be of the same size as the images argument list.

outpref

String. If the outpref string is non-zero in length and contains characters other than a blank space, it will override any value of the outimages argument. Output file names will use the name list provided in the images argument, but adding a prefix to the basename of each output file defined by outpref. An absolute or relative directory path can be included in the prefix, e.g. ‘outpref=/Volumes/data/p’.

(clobber)

Hidden boolean. If set to ‘yes’ files contained within the outpath directory will be overwritten by newly created files of the same name.

(logfile)

String. Name of an ascii file for storing log and error messages from the tool. The file may be new, or messages can also be appended to a pre-existing file.

(verbose)

Hidden Boolean. If verbose=n, log messages will be suppressed.

.ih

DESCRIPTION

SLOTREADTIME is a tool to fix the UTC time. The time in the binary files is the readtime and not the start time of the exposure. The actually time of the exposure is 7xEXPTIME less than the time of the read out as the image is shifted down 7 places on the CCD before being read out.

This program will read in a file, and for each extension correct the UTC-TIME keyword by the time it takes to shift the exposure so the UTC-TIME corresponds to the start of the exposure and adds a keyword with READTIME.

It will not run on files with the READTIME header keyword already in place.

Examples

1. To automatically correct the UTC values in the image``:

   --> slotreadtimefix images="*.fits" outimages='' outpref='r'
   clobber=True logfile=salt.log verbose=y

Time requirements

A linux machine with 2 GB of RAM and a 2.8 Ghz processer was able to process 12 SALTICAM slotmode exposures with 200 extensions in 16 seconds.

Bugs and limitations

Send feedback and bug reports to salthelp@saao.ac.za

See also

saltslot slotview