RE: Fits Header One More Time

["Albertson, Chris" <CAlbertson@primeadvantage.com>]

Just a couple coments.

Actually you can use any units you want.  But for two things:
1) Degrees is the convention.
2) As written your crdelt2 must be wrong.  Is the image scale
   realy -0.002126 hours/pixel?  You've got to use the same units
   in all places.

I'd like to see some lines, (not just a comment) that give the
observer, observatory and camera .  Eventually we
may have a database of results and maybe I'd like to ask it
"Give me only Tom's data.  I think the names of these lines are

TELESCOP
OBSERVER
OBSERVAT

Spelling could be wrong but we are going to need this.  We have to
think of the general case and make a name convention.  There will be
multiple instruments at one location and one person could work at
multiple sites.  There is also the possibility of someone using an SCT
or other non-TASS system.  The above three lines is I think what we need.

> -----Original Message-----
> From: Tom Droege [mailto:tdroege@veriomail.com]
> Sent: Thursday, April 12, 2001 10:06 AM
> To: tass@listserv.wwa.com
> Subject: Fits Header One More Time
> 
> 
> I am getting close.  Below is the fits header taken off last night's 
> run.  It appears that I do not understand the units used for 
> the world 
> coordinates.  Will someone tell me the units used?  I have just gone 
> through a lot of correspondence and no one seems to specify 
> units.  My 
> apologies if someone has done it right.  ;^)  Ahhh!  I just 
> checked one 
> more time and Michael did specify degrees for RA.  Hmmm!  
> Seems like a 
> misnomer to me.
> 
> OK, below is the current header.  I have to fix it so RA is in 
> degrees.  There is also the time difference between DATE and 
> UT.  For this 
> I will have to wait for Rob to start reading these posts again.
> 
> Please check the other units to make sure I have them right.
> 
> At this time I can read the fits files into DS9 and have the 
> cursor make 
> sense.  Getting close.
> 
> Tom Droege
> 
> 
> 
> SIMPLE  =                    T / file does conform to FITS standard
> BITPIX  =                   16 / number of bits per data pixel
> NAXIS   =                    2 / number of data axes
> NAXIS1  =                 2043 / length of data axis 1
> NAXIS2  =                 2037 / length of data axis 2
> EXTEND  =                    T / FITS dataset may contain extensions
> COMMENT   FITS (Flexible Image Transport System) format 
> defined in Astronomy an
> COMMENT   Astrophysics Supplement Series v44/p363, v44/p371, 
> v73/p359, v73/p365
> COMMENT   Contact the NASA Science Office of Standards and 
> Technology for the
> COMMENT   FITS Definition document #100 and other FITS information.
> DATE    = '2001-04-12T03:19:17' / file creation date 
> (YYYY-MM-DDThh:mm:ss UTC)
> FILTER  = 'I       '
> LATITUDE=              41.8271 / Site H latitude, degrees north
> LONGITUD=             -88.3125 / Site H longitude, degrees east
> RALIM   =                 -9.5 / RA Limit Switch Position Degrees East
> DECLIM  =                   0. / Declination limit switch 
> Degrees North
> DATASEC = '[ 17:2064, 1:2048]' / Place keeper for Active area 
> of the detector
> BIASSEC = '[ 10:15, 1:2048]'   / Place keeper for Under-Over 
> scan region
> TIMESYS = 'UT      '           / time system for exposure start
> EPOCH   =                2001. / Place keeper for Epoch of coordinates
> EQUINOX =                2000. / Place keeper for Equinox of 
> coordinates
> SCALE   =                  7.4 / Arc seconds per pixel
> TIMEBASE= 'Manual GPS'         / By hand transfer to PC clock
> COMMENT   Additions to Constant File
> RA      = '10:38:4.88'         / RA of Field Center
> RATIME  = '1.980469'           / Seconds since turning on RA drive
> IMAGETYP= 'object  '           / object frame
> WATERTMP= '20.42651'           / Cooling water temperature
> VCOTEMP = '23.72241'           / VCO Temperature
> DEC     = '0:00:00 '           / Place Keeper for DEC of field center
> CRVAL1  =                   0. / Place Keeper for DEC of field center
> CRVAL2  =     10.6374667713148 / RA of Field Center
> CTYPE1  = 'DEC--TAN'
> CTYPE2  = 'RA---TAN'
> CRPIX1  =                1016.
> CD1_1   =             0.002126
> CRPIX2  =                1015.
> CD2_2   =            -0.002126
> CDELT1  =             0.002126
> CDELT2  =            -0.002126
> CROTA1  =                   0.
> CROTA2  =                   0.
> UT      = '04:19:12'           / Universal time of #0 
> exposure (V) start
> COMMENT   This is the #1 Camera File
> DATE-OBS= '2001-04-12T04:19:14' / UT date-time of exposure start
> UTSTART = '04:19:14'           / Universal time of #1 
> exposure (I) start
> EXPTIME =             99.73926 / Open Time for Camera 1 usually I
> GAIN    =                  2.5 / Place Keeper for Gain in 
> electrons per adu
> RDNOISE =                  25. / Place Keeper for Read Noise 
> in electrons
> CCDTEMP = '-14.97388'          / CCD Temperature Camera 1
> END
> 
> 
>