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 only)
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;
or --> Units for C1 is erg/cm2/ster/A/sec
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
CRPIX1(2) R*4 Any * Column(Row) number of the reference pixel,
which is sun center.
(image sun center NOT 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
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 pixels 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 of image
DATAP01 R*4 Any Intensity of 1st percentile of image
DATAP10 R*4 Any Intensity of 10th percentile image
DATAP25 R*4 Any Intensity of 25th percentile of image
DATAP75 R*4 Any Intensity of 75th percentile of image
DATAP90 R*4 Any Intensity of 90th percentile of image
DATAP95 R*4 Any Intensity of 95th percentile of image
DATAP98 R*4 Any Intensity of 98th percentile of image
DATAP99 R*4 Any Intensity of 99th percentile of image
N_MISSIN R*4 Any Number of missing blocks (1 block=32x32 pix)
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, the following; in general the first three values are
procedure name, SCCS version number, date of last modification. Explanation
of other values are in parenthesis:
HISTORY reduce_level_1.pro 1.14 01/12/01,'32018011.fts','35018011.fts'
(input filename, output filename)
HISTORY offset_bias.pro 1.22 01/09/01, 338.556
(electronic offset bias in DN)
HISTORY get_exp_factor.pro 1.10 08/07/00, 1.00188, Nreg=16, Sig=0.00103000
(exposure time correction factor, number of regions used in calculation,
standard deviation of fit)
HISTORY c3_calfactor.pro 1.8 08/07/00: 5.30000e-13
(absolute calibration factor)
HISTORY c3_calibrate.pro 1.28 01/12/01
HISTORY C3_cl_vig_951201_v03.dat 2001-Jan-11
(file used for vignetting correction)
HISTORY C3ramp.fts 1999-Mar-18
(file used for stray light subtraction)
HISTORY Used FUZZY_IMAGE.PRO to replace some missing blocks.
HISTORY subtense.pro 1.13 08/07/00
HISTORY C3_cl_msk_951201_v03.dat 2001-Jan-11
(file used for mask)
HISTORY get_roll_or_xy.pro 1.14 08/07/00, 517.88800, 531.41602, -0.237017 Deg
(sun center x,y and roll)
HISTORY adjust_date_obs.pro 1.3 08/07/00,'1997/08/18 00:40:26.716'
(original date-obs and time-obs)
COMMENT S*80 Any Comments. Can be repeated
COMMENT Final DATE, TIME-OBS, CRPIX1(2), CROTA from stars, running median values.
COMMENT FITS coordinate for center of full image is (512.5,512.5).
END Last keyword in the FITS header
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