== FITS Keywords ==


||Category B ||Version 3.0.1 ||

[[process_fits]] reads the following keywords and sets the variable.

|| FITS Keyword ||Levels || SPC Variable || Description ||
|| BITPIX ||0/1|| BITPIX || This sets the flag in SPC for how many bits to treat the data.  Everything is eventually converted into unsigned integer.  For ORex, the level 0 data is 16.  The camera is a 14-bit imager, but the SPOC will pad the leading bits to 0 to make it a simple unsigned 16-bit integer.  IF a LUT (look-up-table) is used, the SPOC will convert the 8-bit LUT into the standard 16-bit integers.  For level 1, it is set to -32, which is 32-bit signed.||
||DATE_OBS ||0/1|| UTC0 || The UTC time of the observation.  This is converted within SPC via SPICE into ET, setting both ET0 and ET.||
|| EXPTIME ||0/1|| EXP || The duration of the exposure.  It is used to calculate the midpoint of the exposure.  This is _____ used for OREx.||
|| SCLK_STR ||0/1|| CLK0 and CKLUSE || This is the spacecraft clock.  If this value is set in the FITS headers, it is the primary time used to calculate the midpoint of the exposure.||
|| NAXIS1 ||0/1||  NPX || Number of pixels wide (the x value) ||
||NAXIS2 ||0/1||NLN|| Number of pixels tall (the y value) ||
||CAMERAID ||0/1||CAM|| Which camera is being used.  Values are 0-Map, 1-Sam, 2-Poly   ||
||MTR_POS ||0||FLT||||
||LUT ||0||LUT||||
|| MCFWHTMP ||0/1|| NTX (1,1) || MapCam temperature.  The final algorithm has not been decided yet.  However, the weighting of each temperature can be adjusted in the file [[DN2TEMP.TXT]].  This assumes a linear mixing of the four camera temperatures.  Level 0 is in DN.  Level 1 is in degrees C||
||MCFWMTMP ||0/1|| NTX (1,2) || see above ||
||MCLENTMP ||0/1|| NTX (1,3) || see above ||
||MCROETMP ||0/1|| NTX (1,4)|| see above ||
||SCFWHTMP ||0/1|| NTX (2,1) || SamCam temperature.  The final algorithm has not been decided yet.  However, the weighting of each temperature can be adjusted in the file [[DN2TEMP.TXT]].  This assumes a linear mixing of the four camera temperatures.  Level 0 is in DN.  Level 1 is in degrees C||
||SCFWMTMP ||0/1|| NTX (2,2)|| see above ||
||SCLENTMP ||0/1|| NTX (2,3)|| see above ||
||SCROETMP ||0/1|| NTX (2,4)|| see above ||
||PCFWHTMP ||0/1|| NTX (3,1) || PolyCam temperature.  The final algorithm has not been decided yet.  However, the weighting of each temperature can be adjusted in the file [[DN2TEMP.TXT]].  This assumes a linear mixing of the four camera temperatures.  Level 0 is in DN.  Level 1 is in degrees C||
|| PCFWMTMP ||0/1|| NTX (3,2) || see above ||
|| PCLENTMP ||0/1|| NTX (3,3) || see above ||
|| PCROETMP ||0/1|| NTX (3,4)|| see above ||
|| NCCHTEMP ||0|| NTX (4,0) and NTX (4,1) || NavCam temperature.  ||
|| TCCHTEMP ||0|| NTX (5,0) and NTX (5,1) || TAGCam temperature ||
||SC_QA ||0/1|| QT(0) || Quadterians.  OREx will write the spacecraft pointing information, as of when the image was taken, into the FITS header.  [[process_fits]] will output them in the file [[quaternions.txt]] in the format PICNM, QT(I), I=0,3||
|| SC_QX ||0/1|| QT(1)|| see above ||
|| SC_QY ||0/1|| QT(2)|| see above ||
|| SC_QZ ||0/1|| QT(3)|| see above ||
|| BZERO ||0|| DDN and SIGNED || FORTRAN reads all integers as signed.  Because the data is unsigned, then the DN values less than zero are converted into high-bit values.||
|| INSTRUME ||0/1|| INAME and NC || Level 0 has OCAMS, so NC is set via CAMERAID-1.  This is the name of the instrument in human-readable form.  It sets the variable NC as follows:||
    || INSTRUME || NC ||Comment||
    || MAP ||  || N/A Because INSTRUME will be OCAMS ||
    || SAM ||  || N/A Because INSTRUME will be OCAMS ||
    || POL ||  || N/A Because INSTRUME will be OCAMS ||
    || NCM || 4 ||
    || NFT || 5 ||
    || OCAMS || CAMERAID+1||
The order of this is important because the camera number is the reference that SPC uses for camera ID within the configuration files [[make_sumfiles.txt], [[DN2TEMP]], and [[FLATFIELD.TXT]]