Hi Jared,
right guess. If an image has been taken with SGP
after a successfull plate solve this could be written to the header as well
i.e.
HISTORY File was processed at 2016-03-02T17:13:08
EXPTIME = 6.00000000000E+002 / [sec] Duration of exposure
DATE = ‘10/10/15’ / [old format] UTC date of exposure start
TIME-OBS = ‘20:48:08’ / [old format] UTC time of exposure start
UT = ‘20:48:08’ / [old format] UTC time of exposure start
TIMESYS = 'UTC ’ / Default time system
RADECSYS = 'FK5 ’ / Equatorial coordinate system
CLRBAND = 'R ’ / [J-C std] Std. color band of image or
C=Color
FWHM = 6.00000000000E+002 / [pixels] Mean Full-Width-Half-Max of image
star
ZMAG = 1.57031740690E+001 / Mag zero point for 1 sec exposure
EQUINOX = 2000.0 / Equatorial coordinates are J2000
EPOCH = 2000.0 / (incorrect but needed by old programs)
PA = 2.65391611193E+002 / [deg, 0-360 CCW] Position angle of plate
CDELT1 = 6.42508175242E-004 / [deg/pixel] X-axis plate scale
CROTA1 = -8.53916111928E+001 / [deg] Roll angle wrt X-axis
CDELT2 = 6.42471349447E-004 / [deg/pixel] Y-Axis Plate scale
CROTA2 = -8.53916111928E+001 / [deg] Roll angle wrt Y-axis
CD1_1 = 5.16222320635E-005 / Change in RA—TAN along X-Axis
CD1_2 = 6.40394320310E-004 / Change in RA—TAN along Y-Axis
CD2_1 = -6.40431027051E-004 / Change in DEC–TAN along X-Axis
CD2_2 = 5.16192733001E-005 / Change in DEC–TAN along Y-Axis
TR1_0 = 1.66800022395E+003 / [private] X-axis distortion coefficients
TR1_1 = 3.33599995410E+003
TR1_2 = 5.59855972870E-001
TR1_3 = 2.45189695602E+000
TR1_4 = -7.48476807362E-001
TR1_5 = 1.28336963039E+000
TR1_6 = -1.56693503659E+001
TR1_7 = -1.42415559999E+000
TR1_8 = -1.09928192796E+001
TR1_9 = 2.41483387132E-001
TR1_10 = -3.46008184697E+000
TR1_11 = -2.29046736602E+000
TR1_12 = 3.02630780477E+000
TR1_13 = 2.07902542495E+000
TR1_14 = -4.04578054559E+000
TR2_0 = 1.24799999923E+003 / [private] Y-axis distortion coefficients
TR2_1 = -2.15887070091E-003
TR2_2 = 2.49599999856E+003
TR2_3 = 1.98828330133E+000
TR2_4 = -5.53282816164E-001
TR2_5 = 2.67191081421E-002
TR2_6 = -2.13377648093E+000
TR2_7 = -1.37491134884E+001
TR2_8 = 3.01131415852E-001
TR2_9 = -7.57817208613E+000
TR2_10 = -8.69994128133E+000
TR2_11 = 5.76282577602E+000
TR2_12 = -4.63022427728E+000
TR2_13 = 6.39416054747E-001
TR2_14 = -2.07588885142E+000
HISTORY WCS added at 2016-03-02T17:13:09
HISTORY Matched 392 stars from the Gray GSC-ACT Catalog
HISTORY Average residual was 0.47 arc-seconds
If the image was taken with another software the image scale (if not present in the header)
could be calculated from the given values and written to the solver window.
Robert