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I am having a bizarre problem. I am calculating lst and airmass using asthedit and I've found an instance where it doesn't seem to be working correctly, yet I can't figure out why. This will be long, as I try to be complete.
First, the raw header:
________________________________________________________________________
SIMPLE = T / file does conform to FITS standard
BITPIX = -32 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 1024 / length of data axis 1
NAXIS2 = 1024 / length of data axis 2
EXTEND = T / FITS dataset may contain extensions
COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy
COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
CREATOR = 'Linux Apogee Controller' / Data-taking program
OBSERVAT= 'Springfield, Missouri ' / Observatory Site
TELESCOP= 'BO16" ' / Telescope Name
LATITUDE= '37:13:3 N' / [deg] Observatory Latitude
LONGITUD= '93:17:32 W' / [deg west] Observatory Longtiude
INSTRUME= 'GTcam2 ' / Instrument
DETECTOR= 'CCD4710 ' / CCD Detector ID
INSTID = 'ccd ' / Instrument ID Code
OBSERVER= 'Amanda W. and Mike' / Observer(s)
OBJECT = 'WASP14b ' / Target Name
IMGTYPE = 'Object ' / Image type code
EXPTIME = 45.00 / [sec] Exposure time
DARKTIME= 0 / Dark time during exposure
TIMESYS = 'UTC ' / Time System is UTC
DATE-OBS= '2013-06-12' / Date of start of observation
TIME-OBS= '03:46:39.23' / Time of start of observation
MJD-OBS = 56455.157396 / MJD at start of obs
JD = 2456455.65740 / Julian Date at start of obs
EQUINOX = 2013.50 / Equinox of coordinates
RA = '00:00:00.00' / Object RA at EQUINOX
DEC = '+00:00:00.00' / Object DEC at EQUINOX
SECZ = 0.000 / Secant of ZD at start of obs
FILTER = 0 / Filter wheel position [1-8]
FILTERID= 'none ' / FilterID
SHUTTER = 'OPEN ' / shutter state
TECOOLER= 'ON ' / TE Cooler state
CCDTEMP = -99.0 / [C] CCD temperature at readout
CCDXBIN = 1 / Column Binning on detector
CCDYBIN = 1 / Row Binning on detector
GAIN = 1.00 / [e-/ADU] CCD gain
END
__________________________________________________end of raw header.
I'm using a cmdsA file. here that is:
________________________________________________
observat = "baker"
ra = "14:33:06.00"
dec = "21:53:41.00"
epoch = "2000.0"
object = "Wasp14"
epscor = "A"
imagetyp = "object"
lst = mst (@'date-obs', 'time-obs', obsdb (observat, "longitude"))
airmass = airmass (ra, dec, lst, obsdb (observat, "latitude"))
_______________________________________________
After running the command asthedit temp12Jun13r0001 cmdsA table=""
the end of the header looks like this:
____________________________________________
OBSERVAT= 'baker '
RA = '14:33:06.00'
DEC = '21:53:41.00'
EPOCH = '2000.0 '
OBJECT = 'Wasp14 '
EPSCOR = 'A '
IMAGETYP= 'object '
LST = '11:09:45.66'
AIRMASS = 1.44399042228207
_______________________________________
I *know* that the hour angle was only 20 minutes, so the airmass is too high.
I also know that the time-obs in the header is UTC and is correct (time written down from in log file from other source).
If I move the lst 2 hours ahead by doing the following:
hedit temp12Jun13r0001.imh lst "13:09:45.66" add+ ver-
and check using:
setairmass temp12Jun13r0001.imh
# Image UT middle effective begin middle end updated
# SETAIRMASS: Observatory parameters for Baker Observatory
# latitude = 37:23:55.05
temp12Jun13r0001.imh 3:47:01.7 1.0929 1.0935 1.0929 1.0924 no
this looks correct, though clearly it's not using UT (as it shows), but lst (which I changed).
So maybe the clock was off by 2 hours (even though the time is correct as written in the log, but irrelevant to the problem). So I change the time-obs time.
hedit temp12Jun13r0001.imh time-obs "05:46:39.23" add+ ver-
and run the asthedit command again:
asthedit tempbak04Sep13Er0001.imh cmdsE table=""
but the end looks like this:
___________________________________________________
LST = '11:09:45.66'
AIRMASS = 1.44399042228207
_________________________________________________
the lst and airmass remain the same, even though I changed the time![/i]
I have also gone through and re-ran setjd to update JD and HJD in the header, changed the EQUINOX keyword from 2013.5 to 2000.0, all to no effect.
If I change the lst by 2 hours to the "13:09:45.66" value, comment out the lst line of the cmdsA file and rerun the asthedit command, then the airmass is calculated correctly.
I have images from a different detector, and so a slightly different header, and these work fine. If I change the time of the image, lst and airmass change, as they should.

And so the problem is this: why doesn't changing the time-obs change the lst?[/i][/u]
for this header, when it does for others?
Thanks in advance for the help.

I think the problem is in your cmdsA file, specifically, the line:



In this case, you should specify "@'time-obs'" to use the value of the TIME-OBS keyword, not the 'time-obs' string. With this I get an airmass value of 1.04204574044218

Note also the DATE-OBS keyword should contain the time per the Y2K spec, e.g. "DATE-OBS='2013-06-12T03:46:39.23'" but I don't think this is affecting the value as much as the missing '@' is.