PARSEKEY

Name

parsekey

Purpose

Extract FITS header information by parsing supplied keys

Description

Note: the DATE-OBS keyword often now holds the date and the time both, joined
by a T between the two fields, example: 2013-08-05T23:27:15. You can
associate both DATE and UT with this keyword and DATE will only take
what preceeds the T and UT will take what follows the T.

Calling Sequence

parsekey,hdr,keylist,info

Inputs

hdr - String array containing the FITS header to "read"
keylist - 3,n element string array. For each key, there are three elements:
0 - "standard" key name
1 - item descriptor, K - keyword, T - template, V - value,
W - keyword but just take first word.
2 - information (contents match what descriptor indicates)

Optional Input Parameters

Keyword Input Parameters

UNKNOWN - This is a two-element string array. The first element is the
"name" of a filter to look for. If this name is found then
it is replaced by the string in the second element. This is
used to rename a filter that is tagged in the header as unknown.
The default is ['',''] which does nothing.

Outputs

info - Anonymous structure containing information gleaned from header.
tags:
airmass - float value for airmass as read from header
jd - Double, julian date of middle of exposure
date - String containing the UT date.
ut - String containing the UT start time of the image.
expdelta - Time, in seconds between successive frames if
the image is 3-d, not relevant otherwise
exptime - Exposure time in seconds.
imfile - Original filename of image.
filter - String that identifies the filter used.
If you use a keyword that grabs more than
one position (eg., FILT_*) then this field
will contain information about all the filters
in wheel order where the filter strings are
separated by '+'.
object - String that identifies the object imaged.
ra - Right ascension of object (radians) (< 0 if invalid).
dec - Declination of object (radians) ( < -100 if invalid).

Keyword Output Parameters

Common Blocks

Side Effects

Restrictions

Procedure

Modification History

1997/09/05, Written by Marc W. Buie, Lowell Observatory
2000/02/05, MWB, added kludge fix for new DATA-OBS "Y2K" format.
2002/09/03, MWB, changed Str_sep call to strsplit
2006/07/13, MWB, changed to support multiple filter wheel instruments
2006/08/09, MWB, changed to strip path from file name if found.
2011/01/25, MWB, added UNKNOWN keyword
2013/08/05, MWB, added fix to allow getting time from DATE-OBS keyword