The following table has 4 columns, KEYWORD, TYPE, VALUES, and DESCRIPTION.
KEYWORD gives the name of the FITS keyword and may be up to 8 characters.
TYPE refers to the data type and the size of the data:
S String I Integer R RealThe size of the data depends upon the data type. For example S*2 is a 2 character string, whereas I*2 is a 2 byte integer (16 bits).
VALUES shows the range of values that the KEYWORD can take.
DESCRIPTION gives a short description of the keyword. An asterisk (*) indicates the value will (probably) be different than level 0.5. Those keywords which have been omitted for the level 1 header are listed at the end.
For more information on usage of FITS keywords in SolarSoft, see www.lmsal.com/solarsoft/ssw_standards.html.
KEYWORD TYPE VALUES DESCRIPTION
========================================================================
SIMPLE S*1 T Conforms to FITS standard
BITPIX I*2 32 * Number of bits per pixel
NAXIS I*2 2 Number of axes in the image
NAXIS1 I*2 Positive Length of the first axis (columns,x)
Number
NAXIS2 I*2 Positive Length of the second axis (rows,y)
Number
DATE S*23 Any * Date of file generation in CSSDS
standard format, eg
1996/05/21 17:28:48.208
FILENAME S*30 Any * Name of the FITS file. DLNNNNNN.fts,
where D is [123] for detector, L is [45]
for intermediate level 1 or 6 for final
Level 1, and NNNNNN is the number of the
original level 0.5 image
FILEORIG S*17 Any Name of the raw telemetry file in
the format YYMMDD_HHMMSS.img. The
implied date and time are the date
and time stamp of when the data
were put into the telemetry stream.
DATE-OBS S*10 Any * Date of the start of the exposure,
eg: 1996/05/20 (corrected)
TIME-OBS S*12 Any * Time of the start of the exposure,
eg: 00:40:05.407 (corrected)
EXPTIME R*4 Any * Number of seconds of the exposure time
(corrected)
TELESCOP S*8 SOHO Name of the satellite
INSTRUME S*8 LASCO Name of the instrument
DETECTOR S*8 C1,C2,C3 Name of the telescope within LASCO
SUMROW I*2 0,2,4 Number of rows being summed on the CCD
SUMCOL I*2 0,2,4 Number of columns being summed on the CCD
LEBXSUM I*2 1,2,4,.. Number of columns being summed in the LEB
LEBYSUM I*2 1,2,4,.. Number of rows being summed in the LEB
FILTER S*8 Clear Position of the filter wheel
Orange
FeXIV
FeX
CaXV
Blue
Red
IR
Lens
POLAR S*8 Clear Position of the polarizer wheel
0 deg
+60 deg
-60 deg
H alpha
ND
COMPRSSN S*8 Code indicating the steps used in compressing the
data
MID_DATE I*2 Any * Modified Julian Date at the mid-
point of the exposure (corrected)
MID_TIME R*4 Any * Number of seconds of the day at the
mid-point of the exposure (corrected)
WAVELENG R*8 Any Wavelenth of FP (C1) or
Bandpass of filter(???) (C2 & C3)
R1COL I*2 Any The rectified coordinate, equivalent to P1COL,
as though the image had been read out with this
coordinate
R1ROW I*2 Any Rectified P1ROW
R2COL I*2 Any Rectified P2COL
R2ROW I*2 Any Rectified P2ROW
BUNIT S*20 MSB Units for C2 and C3 are mean solar brightness;
& --> Units for C1 is erg/cm2/ster/A/sec
CRPIX1,2 R*4 Any * Column(Row) number of the reference pixel,
which is sun center. For a full size image,
this will always be 512.5: [NAXIS1(2)+1]/2
(image sun center shifted to ctr in level 1)
CROTA R*4 0 Rotation angle of image about axis perpendicular
to the plane of the image. Specified in degrees
CCW relative to the Y direction (corrected in
level 1)
CRVAL1,2 R*4 Any The reference data coordinates corresponding
to CRPIX1 and CRPIX2. For example, if the
pixel coordinates specify the origin, then
set CRVAL1 and CRVAL2 to zero.
CTYPE1,2 S*8 ARCSEC Definition of the data units - ie., the
interpretation of CDELT1 and CDELT2. For example,
if your telescope has a platescale of 2.6 arcsec
per pixel, set CDELT1 to 2.6 and set CTYPE1 to
"arcsec".
CDELT1,2 R*8 Any * The width and height of a pixel in data units,
where units are specified by CTYPE1(2)
(Same as PLATESCL)
XCEN R*4 Any East-West FOV center of image relative to sun
center in CDELT1 units, positive West. XCEN
is related to the above FITS keywords by:
XCEN = CRVAL1 + CDELT1 * [(NAXIS1+1)/2 - CRPIX1]
(units = arcseconds)
YCEN R*4 Any North-South FOV center of image relative to sun
center in CDELT2 units, positive North. YCEN
is related to the above FITS keywords by:
YCEN = CRVAL2 + CDELT2 * [(NAXIS2+1)/2 - CRPIX2 ]
(units = arcseconds)
DATE_OBS S*23 Any (new field, SolarSoft requirement)
DATE-OBS+' '+TIME-OBS
SOLAR_R R*4 Any Radius of sun (Arcseconds)
DATAMIN R*4 Any Minimum value of the image, including the bias
DATAMAX R*4 Any Maximum value of the image
DATAZER I*4 Any Number of zero pixels in the image
DATASAT I*4 Any Number of saturated values in the image
DSATVAL R*4 Any Value used as saturated
DATAAVG R*4 Any Average value of the image
DATASIG R*4 Any Standard deviation in computing the average
DATAP01 I*4 Any Intensity of 1st percentile of image
DATAP10 I*4 Any Intensity of 10th percentile image
DATAP25 I*4 Any Intensity of 25th percentile of image
DATAP75 I*4 Any Intensity of 75th percentile of image
DATAP90 I*4 Any Intensity of 90th percentile of image
DATAP95 I*4 Any Intensity of 95th percentile of image
DATAP98 I*4 Any Intensity of 98th percentile of image
DATAP99 I*4 Any Intensity of 99th percentile of image
MISSLIST S*80 Any Space-delimited list of missing blocks. The numbers are the 1D
subscripts of a 32x32 array representing superpixels
of the array.
N_MISSIN I*4 Any Number of missing blocks (should not include occulter or corners)
COMMENT S*80 Any Comments. Can be repeated
COMMENT S*80 Any 'FITS coordinate for center of full image is (512.5,512.5).'
COMMENT Final DATE-OBS, TIME-OBS, sun center, roll angle computed from star positions,
running median values
HISTORY S*80 Any History. Can be repeated.
Carried over from level 0.5 header (example):
HISTORY V15 18 Jun 1997 MAKE_FITS_HDR
HISTORY V24 12 Jun 98 reduce_level_05,'980505_145639.img','32027129.fts',2
In addition:
HISTORY Vxx dd mmm yyyy reduce_level_1,'d2nnnnnn.fts','d5nnnnnn.fts'
HISTORY Vxx dd mmm yyyy get_exp_factor, old_exp_time, bias
HISTORY Vxx dd mmm yyyy vigfilename.fts
HISTORY Vxx dd mmm yyyy c3_calfactor, calib_factor
HISTORY Vxx dd mmm yyyy c3_warp
HISTORY Vxx dd mmm yyyy get_roll_or_xy, original_roll, original_cx, original_cy
HISTORY Vxx dd mmm yyyy adjust_date_obs,'old_date_obs','old_time_obs'
END Last keyword in the FITS header
Unused FITS keywords:
========================================================================
BSCALE R*8 Any If missing, then assumed to be 1
output data = FITS data * BSCALE + BZERO
BZERO R*8 Any If missing, then assumed to be zero
OLD KEYWORDS from Level 0.5, not used in Level 1
========================================================================
OBT_TIME R*4 Any Value of the On-Board Time
EXP0 R*4 Any Measured exposure delay time
EXPCMD R*4 Any Commanded exposure delay time
EXP1 R*4 Any Length of time since CCD clear
EXP2 R*4 Any Length of time to open shutter
EXP3 R*4 Any Length of time to close shutter
READPORT S*1 A,B,C,D CCD readout port
SHUTTR I*2 0 Shutter was commanded open during the exposure
1 Shutter was not commanded during the exposure
LAMP I*2 0 Calibration lamp was not commanded on
1 Calibration lamp was commanded on
LP_NUM S*8 Normal Description of the LEB Program (LP) used to
Cal Lamp generate the image
Dark
Line Scan
Pol Seq
OS_NUM I*2 Any Observing Sequence Number
An arbitrary number that specifies similar
instrument configuration and can be used to search
the data base for other exposures taken under the
same conditions.
IMGCTR I*2 Any Sequential counter since the last LEB reboot
IMGSEQ I*2 Any Number of the image in the current sequence,
starting at 0
PLATESCL R*4 Any Number of arc seconds per pixel
OFFSET I*2 Any Electronic offset in DN
P1COL I*2 Any CCD column number of start of image, 0-19 are
underscan pixels, 20-1043 are imaging pixels,
1044 - 32000 are overscan pixels
P1ROW I*2 Any CCD row number of start of image, 1-1044 are
imaging rows, 1025-32000 are overscan rows
P2COL I*2 Any CCD column number at end of image, 0-19 are
underscan pixels, 20-1043 are imaging pixels,
1044 - 32000 are overscan pixels
P2ROW I*2 Any CCD row number at end of image, 1-1044 are
imaging rows, 1025-32000 are overscan rows
RECTIFY S*8 TRUE Status of rectification to put solar north
FALSE to the top of the image
EFFPORT S*8 A,B,C,D Rectified read out port
VERSION I*2 Any Version number of LEB header
CROTA1 R*4 0 Rotation of axis 1 with respect to solar north
Positive is westward (clockwise)
CROTA2 R*4 0 Rotation of axis 2 with respect to solar north
Positive is westward (clockwise)
CUNIT1 S*8 ARCSEC Units along axis #1
CUNIT2 S*8 ARCSEC Units along axis #1