FITS Keywords
Category B |
Version 3.0.1 |
Description
This list shows the keyword that process-fits reads, the SPC variable it sets and a description explaining the setting.
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 |
0/1 |
FLT |
Defines the position of the PolyCam motor, which is used to calculate its focal position. For MapCam and SamCam, it provides the position of the filter wheel in degrees. |
LUT |
0 |
LUT |
If LUT is defined, this tells what LUT was used on the spacecraft. No processing is done via SPC because the SPOC has already done it. This variable isn't used |
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.