Description of the EIT FITS Files Headers


 

EIT data are stored in FITS files.


SIMPLE = T / Written by IDL: 23-Apr-1998 19:23:24.00

Creation


BITPIX = 16 / Short integer (2 bytes/word)

EIT images are store as 16 bits/pixel non-signed integer images


NAXIS = 2 /
Number of dimensions
NAXIS=2 image
NAXIS=3 data cube

NAXIS1 = 1024 / Number of columns
NAXIS2 = 1024 / Number of rows

DATE = '23/04/98' / Date of file creation

TIME-OBS= '23:39:25' /
DATE-OBS= '29-FEB-96' / UTC at spacecraft

ORIGIN = 'Rocket Science' / Rocket Science = NASA GSFC
DATASRC = 'LZ file ' /
TELESCOP= 'SOHO' /
INSTRUME= 'EIT' /
OBJECT = 'full FOV' /

BSCALE = 1. /
BZERO = 0. /
BUNIT = 'counts / pixel ' /

WAVELNTH= 284 / 171 = Fe IX/X, 195 = Fe XII,
/ 284 = Fe XV, 304 = He II
FILTER = 'Al +2 ' /

DATE_OBS= '1996-02-29T23:39:25.428Z' /
SCI_OBJ = '284 SEQUENCE IN AL INF ' /
OBS_PROG= '284_60SEC_ALINF.000 ' /
CMP_NO = 1 / Unique campaign instance (1 = synoptic)
EXPTIME = 62.100 / s (total commanded + shutter close)
EXPMODE = 'backside ' /
FILENAME= 'efz19960229.233925' /

CFTEMP = -66.71 / CCD cold finger temperature (C)
CCDTEMP = 7.55 / CCD temperature (DN/100)

CTYPE1 = 'Solar-X ' /
CTYPE2 = 'Solar-Y ' /


CRPIX1 = 506.900 / Sun center x, EIT pixels
CRPIX2 = 589.300 / Sun center y, EIT pixels
Note : the lower left corner pixel is (1, 1)

CRVAL1 = 0.00 /
CRVAL2 = 0.00 /

CDELT1 = 2.629 / Pixel scale x (arc sec, fixed)
CDELT2 = 2.629 / Pixel scale y (arc sec, fixed)
The EIT plate scale is identical in X and Y.

SOLAR_R = 371.509 / Solar photospheric radius, EIT pixels
The apparent solar photospheric radius expressed in EIT pixel. The size of an EIT pixel is 2.269 arcseconds and is contained in the CDELT1 and CDELT2. The apparent solar photospheric radius varies with the Sun to SOHO distance.

SOLAR_B0= -7.21 / Degrees
SC_X0 = 0.00 / s/c yaw (arc sec)
SC_Y0 = 0.00 / s/c pitch (arc sec; -109.14 after 1996/04/16)

SC_ROLL = -0.05 / s/c roll (deg., Solar north + CCW from nominal)
HEC_X = -138886544.00 / s/c heliocentric ecliptic x (km)
HEC_Y = 48173424.00 / s/c heliocentric ecliptic y (km)
HEC_Z = 91409.52 / s/c heliocentric ecliptic z (km)
CAR_ROT = 1906.00 / Carrington rotation at earth

COMMENT CORRECTED DATE_OBS = '1996-02-29T23:39:25.428Z'
COMMENT COMMANDED EXPOSURE TIME = 60.000 s
COMMENT SHUTTER CLOSE TIME = 2.100 s
COMMENT LINE_SYNC = 'no'
COMMENT CAMERA_ERR = 'no'
COMMENT IMAGE_OF_SEQ = 0
COMMENT READOUT PORT = 'B'
COMMENT NUM_LEB_PROC = 3
COMMENT LEB_PROC = 26 (no ROI)
COMMENT LEB_PROC = 27 (no occ mask)
COMMENT LEB_PROC = 12 (Rice)


COMMENT BLOCKS_HORZ = 32
COMMENT BLOCKS_VERT = 32
Size of the image in blocks. A block is 32x32 pixels.

COMMENT P1_X = 1
COMMENT P2_X = 1024
COMMENT P1_Y = 20
COMMENT P2_Y = 1043

Coordinates of the lower left and top right corner of the image. The 20 first lines (lines 0 to 19) are "virtual" lines.


COMMENT N_MISSING_BLOCKS = 0
HISTORY Version 4.0, 2001 December 10, Pointing update.

END



Web curator: Frédéric Auchère
Responsible NASA official: Joseph B. Gurman, Facility Scientist, Solar Data Analysis Center
joseph.b.gurman@gsfc.nasa.gov
+1 301 286-4767
NASA Goddard Space Flight Center
Solar Physics Branch / Code 682

Last revised: Tuesday, January 22, 2002 8:53 AM - F. Auchère