2.4 Headers and Keywords

Both the primary and extension headers in a WFC3 science data file contain keywords. These keywords store a wide range of information about the observations themselves (e.g., observing mode, exposure time, detector, etc.), as well as any processing done or to be done on the data.

The primary header keywords apply to all extensions in the FITS file. The extension headers carry extension-specific keywords, i.e., information relevant only to the image in a particular extension. For example, observation parameters, calibration switches, and reference file names are stored in the primary header. Exposure time and World Coordinate System information, on the other hand, are stored in the extension headers because this information can vary from one set of extensions to another.

In Table 2.8 and Table 2.9, we list the WFC3 keywords that appear in the primary header and SCI extension header, respectively. Columns 1 and 2 give the name of the keyword and a short description. The third column gives the format used for the value of the keyword: "L" for boolean values, "C" for characters, "R" for real values and "I" for integer values, followed by the precision of the value. Columns 4 and 5 show to which detector the keyword applies.

Table 2.10 lists the keywords that appear in the headers of the ERR, DQ, SAMP, and TIME extensions belonging to an imset in a WFC3 data file. Note that the SAMP and TIME extensions apply only to IR data.

AstroDrizzle adds additional keywords which are not listed in this handbook, and when it adds extensions does not update the NEXTEND keyword value. Consult the AstroDrizzle Handbook for further information. Users can use the STDAS task catfits (or the python task fits.info) to see all extensions in a file. The pattern keywords refer to the WFC3 dithering patterns available which are discussed in greater detail in Section 4.2.

Table 2.8: WFC3 Primary Header Keywords 

KeywordDescriptionFormatUVISIR
SIMPLE

data conform to FITS standard

L1

Y

Y

BITPIX

bits per data value

I2

Y

Y

NAXIS

number of data axes

I2

Y

Y

EXTEND

file may contain standard extensions

L1

Y

Y

NEXTEND

number of standard extensions

I2

Y

Y

GROUPS

image is in group format

L1

Y

Y

DATE

date this file was written (yyyy-mm-dd)

C10

Y

Y

FILENAME

name of file

C39

Y

Y

FILETYPE

type of data found in data file

C09

Y

Y

TELESCOP

telescope used to acquire data

C03

Y

Y

INSTRUME

identifier for instrument used to acquire data

C06

Y

Y

EQUINOX

equinox of celestial coordinate system

R4

Y

Y

DATA DESCRIPTION KEYWORDS





ROOTNAME

rootname of the observation set

C34

Y

Y

IMAGETYP

type of exposure identifier

C18

Y

Y

PRIMESI

instrument designated as prime

C06

Y

Y

TARGET INFORMATION





TARGNAME

proposer's target name

C30

Y

Y

RA_TARG

right ascension of the target (deg) (J2000)

R8

Y

Y

DEC_TARG

declination of the target (deg) (J2000)

R8

Y

Y

PROPOSAL INFORMATION





PROPOSID

PEP proposal identifier

I4

Y

Y

LINENUM

proposal logsheet line number

C15

Y

Y

PR_INV_L

last name of principal investigator

C30

Y

Y

PR_INV_F

first name of principal investigator

C20

Y

Y

PR_INV_M

middle name initial of principal investigator

C20

Y

Y

EXPOSURE INFORMATION





SUNANGLE

angle between sun and V1 axis

R4

Y

Y

MOONANGL

angle between moon and V1 axis

R4

Y

Y

SUN_ALT

altitude of the sun above Earth's limb

R4

Y

Y

FGSLOCK

commanded FGS lock (FINE, COARSE, GYROS, UNKNOWN)

C18

Y

Y

GYROMODE

number of gyros scheduled for observation

C1

Y

Y

REFFRAME

guide star catalog version

C8

Y

Y

DATE-OBS

UT date of start of observation (yyyy-mm-dd)

C10

Y

Y

TIME-OBS

UT time of start of observation (hh\:mm\:ss)

C08

Y

Y

EXPSTART

exposure start time (Modified Julian Date)

R8

Y

Y

EXPEND

exposure end time (Modified Julian Date)

R8

Y

Y

EXPTIME

exposure duration (seconds)--calculated

R4

Y

Y

EXPFLAG

exposure interruption indicator

C13

Y

Y

QUALCOM1

data quality comment 1

C68

Y

Y

QUALCOM2

data quality comment 2

C68

Y

Y

QUALCOM3

data quality comment 3

C68

Y

Y

QUALITY

data quality summary

C68

Y

Y

POINTING INFORMATION





PA_V3

position angle of V3-axis of HST (deg)

R4

Y

Y

TARGET OFFSETS (POSTARGS)





POSTARG1

POSTARG in axis 1 direction

R4

Y

Y

POSTARG2

POSTARG in axis 2 direction

R4

Y

Y

DIAGNOSTIC KEYWORDS





OPUS_VER

OPUS software system version number

C18

Y

Y

CAL_VER

CALWF3 code version

C24

Y

Y

PROCTIME

pipeline processing time (MJD)

R8

Y

Y

SCIENCE INSTRUMENT CONFIGURATION





OBSTYPE

observation type - imaging or spectroscopic

C14

Y

Y

OBSMODE

operating mode

C10

Y

Y

SCLAMP

lamp status, NONE or name of lamp which is on

C14

Y

Y

NRPTEXP

number of repeat exposures in set: default 1

I2

Y

Y

SUBARRAY

data from a subarray (T) or full frame (F)

L1

Y

Y

DETECTOR

detector in use: UVIS or IR

C04

Y

Y

FILTER

element selected from filter wheel

C07

Y

Y

APERTURE

aperture name

C16

Y

Y

PROPAPER

proposed aperture name

C16

Y

Y

DIRIMAGE

direct image for grism or prism exposure

C09

Y

Y

NSAMP

number of MULTIACCUM samples

I2

N

Y

SAMP_SEQ

MULTIACCUM exposure time sequence name

C08

N

Y

SAMPZERO

sample time of the zeroth read (sec)

R4

N

Y

SUBTYPE

size/type of IR subarray

C08

N

Y

CTEIMAGE

type of Charge Transfer Image, if applicable

C04

Y

N

CTEDIR

serial or parallel

C08

Y

N

CRSPLIT

number of cosmic ray split exposures

I2

Y

N

CTE CORRECTION PARAMETERS





CTE_NAME

name of the CTE algorithm

C23

Y

N

CTE_VER

Version number of the CTE algorithm

C23

Y

N

CTEDATE0

Date of WFC3/UVIS installation in HST (MJD)

R8

Y

N

CTEDATE1

Reference date of CTE model pinning (MJD)

R8

Y

N

PCTETLEN

Maximum length of CTE trail

R8

Y

N

PCTERNOI

Read noise amplitude

R8

Y

N

PCTENFOR

Number iterations used in CTE forward modeling

I4

Y

N

PCTENPAR

Number of iterations used in parallel transfer

I4

Y

N

PCTENSMD

read-noise mitigation algorithm

I4

Y

N

PCTETRSH

over-subtraction threshold

R8

Y

N

PCTEFRAC

Scaling of CTE model (relative to CTEDATE1)

R8

Y

N

FIXROCR

Fix readout cosmic rays

I4

Y

N

SCAN KEYWORDS





SCAN_TYP

Type of scanning path

C18

Y

Y

SCAN_WID

scan width (arcsec)

R8

Y

Y

ANG_SIDE

angle between sides of parallelogram (deg)

R8

Y

Y

DWELL_LN

dwell pts/line for scan pointing

I4

Y

Y

DWELL_TM

wait time at each dwell point (sec)

R8

Y

Y

SCAN_ANG

position angle of scan line (deg)

R8

Y

Y

SCAN_RAT

commanded rate of the line scan (arcsec/sec)

R8

Y

Y

NO_LINES

number of lines per scan

I4

Y

Y

SCAN_LEN

scan length (arcsec)

R8

Y

Y

SCAN_COR

scan coordinate frame of ref: (celestial,vehicle)

C18

Y

Y

CSMID

Channel Select Mechanism ID (UVIS/IR)

C7

Y

Y

POST-SAA DARK KEYWORDS





SAA_EXIT

time of last exit from SAA contour level 23

C17

N

Y

SAA_TIME

seconds since last exit from SAA contour 23

I4

N

Y

SAA_DARK

association name for post-SAA dark exposures

C09

N

Y

SAACRMAP

SAA cosmic ray map file

C18

N

Y

CALIBRATION SWITCHES: PERFORM, OMIT, COMPLETE, SKIPPED





DQICORR

data quality initialization

C08

Y

Y

BLEVCORR

subtract bias level measured from overscan, (UVIS) or reference pixels (IR)

C08

Y

Y

CRCORR

combine observations to reject cosmic rays/, identify cosmic ray hits

C08

Y

Y

DARKCORR

subtract dark image

C08

Y

Y

FLATCORR

flat-field data

C08

Y

Y

FLUXCORR

Scale the UVIS chips to get uniform flux correction

C08

Y

N

PCTECORR

Perform the pixel based CTE correction

C08

Y

N

PHOTCORR

populate photometric header keywords

C08

Y

Y

DRIZCORR

drizzle processing

C08

Y

Y

NLINCORR

correct for detector nonlinearities

C08

N

Y

RPTCORR

combine individual repeat observations

C08

N

Y

UNITCORR

convert to count rates (see also BUNIT)

C08

N

Y

ZSIGCORR

zero read signal correction

C08

N

Y

ZOFFCORR

subtract MULTIACCUM zero read

C08

N

Y

ATODCORR

correct for A to D conversion errors

C08

Y

N

BIASCORR

subtract bias image

C08

Y

N

EXPSCORR

process individual observations after cr-reject

C08

Y

N

FLSHCORR

post flash correction

C08

Y

N

SHADCORR

apply shutter shading correction

C08

Y

N

CALIBRATION REFERENCE FILES





BPIXTAB

bad pixel table

C23

Y

Y

CCDTAB

detector calibration parameters

C23

Y

Y

OSCNTAB

table containing overscan (UVIS) or reference pixel (IR) locations

C23

Y

Y

CRREJTAB

cosmic ray rejection parameters

C23

Y

Y

DARKFILE

superdark image file name

C23

Y

Y

PFLTFILE

pixel to pixel flat-field file name

C23

Y

Y

DFLTFILE

delta flat-field file name

C23

Y

Y

LFLTFILE

low order flat

C23

Y

Y

COMPTAB

the HST components table


 

Y

Y

IDCTAB

distortion coefficients table

C23

Y

Y

DGEOFILE

distortion correction image (no longer used, kept in the header for compatibility)

C23

Y

Y

MDRIZTAB

AstroDrizzle parameter table

C18

Y

Y

NLINFILE

detector nonlinearities file

C23

N

Y

ATODTAB

analog to digital correction file

C23

Y

N

BIASFILE

superbias image file name

C23

Y

N

FLSHFILE

post flash correction file name

C23

Y

N

SHADFILE

shutter shading correction file

C23

Y

N

PCTETAB

The default parameters and reference data for the CTE correction

C18

Y

N

IMPHTTAB

The default values for the photometric keywords

C18

Y

Y

DRKCFILE

Superdark reference for CTE corrected files

C23

Y

N

BIACFILE

Superbias reference for CTE corrected files

C23

Y

N

SNKCFILE

map of sink-pixel locations

C23

Y

N

D2IMFILE

2-D non-polynomial distortion correction table

C23

Y

N

NOPOLFILE

2-D non-polynomial filter dependent distortion

C23

Y

N

COSMIC RAY REJECTION ALGORITHM PARAMETERSC23





MEANEXP

reference exposure time for parameters

R4

Y

Y

SCALENSE

multiplicative scale factor applied to noise

R4

Y

Y

INITGUES

initial guess method (MIN or MED)

C03

Y

Y

SKYSUB

sky value subtracted (MODE or NONE)

C04

Y

Y

SKYSUM

sky level from the sum of all constituent images

R4

Y

Y

CRSIGMAS

statistical rejection criteria

C15

Y

Y

CRRADIUS

rejection propagation radius (pixels)

R4

Y

Y

CRTHRESH

rejection propagation threshold

R4

Y

Y

BADINPDQ

data quality flag bits to reject

I2

Y

Y

REJ_RATE

rate at which pixels are affected by cosmic rays

R4

Y

Y

CRMASK

flag CR-rejected pixels in input files (T/F)

L1

Y

Y

MDRIZSKY

sky value computed by AstroDrizzle

R4

Y

Y

PHOTOMETRY KEYWORDS 
(contained in this extension for IR, in the SCI extension for UVIS, see Table 2.9)





PHOTMODE

observation configuration for photometric calibration

C50

N

Y

PHOTFLAM

inverse sensitivity, ergs/cm2/Ang/electron

R8

N

Y

PHOTFNU

inverse sensitivity, Jy* sec/electron

R8

N

Y

PHOTZPT

ST magnitude zero point

R4

N

Y

PHOTPLAM

pivot wavelength (Angstroms)

R4

N

Y

PHOTBW

RMS bandwidth of filter plus detector

R4

N

Y

POST FLASH PARAMETERS





FLASHDUR

exposure time in seconds: 0.1 to 409.5

R4

Y

N

FLASHCUR

post flash current (zero, low, medium, high)

C07

Y

N

FLASHSTA

status: SUCCESSFUL, ABORTED, NOT PERFORMED

C16

Y

N

FLASHLVL

requested APT post flash, electrons/pixel

R4

Y

N

SHUTRPOS

shutter position: A or B

C05

Y

N

CHARGE INJECTION PARAMETERS





CHINJECT

charge injection mode

C08

Y

N

OTFR KEYWORDS





T_SGSTAR

OMS calculated guide star control

C18

Y

Y

PATTERN KEYWORDS





PATTERN1

primary pattern type

C24

Y

Y

P1_SHAPE

primary pattern shape

C18

Y

Y

P1_PURPS

primary pattern purpose

C10

Y

Y

P1_NPTS

number of points in primary pattern

I2

Y

Y

P1_PSPAC

point spacing for primary pattern (arc-sec)

R4

Y

Y

P1_LSPAC

line spacing for primary pattern (arc-sec)

R4

Y

Y

P1_ANGLE

angle between sides of parallelogram patt (deg)

R4

Y

Y

P1_FRAME

coordinate frame of primary pattern

C09

Y

Y

P1_ORINT

orientation of pattern to coordinate frame (deg)

R4

Y

Y

P1_CENTR

center pattern relative to pointing (yes/no)

C03

Y

Y

PATTERN2

secondary pattern type

C24

Y

Y

P2_SHAPE

secondary pattern shape

C18

Y

Y

P2_PURPS

secondary pattern purpose

C10

Y

Y

P2_NPTS

number of points in secondary pattern

I2

Y

Y

P2_PSPAC

point spacing for secondary pattern (arc-sec)

R4

Y

Y

P2_LSPAC

line spacing for secondary pattern (arc-sec)

R4

Y

Y

P2_ANGLE

angle between sides of parallelogram patt (deg)

R4

Y

Y

P2_FRAME

coordinate frame of secondary pattern

C09

Y

Y

P2_ORINT

orientation of pattern to coordinate frame (deg)

R4

Y

Y

P2_CENTR

center pattern relative to pointing (yes/no)

C03

Y

Y

PATTSTEP

position number of this point in the pattern

I2

Y

Y

ENGINEERING PARAMETERS





CCDAMP

CCD amplifier readout configuration

C04

Y

Y

CCDGAIN

commanded gain of CCD

R4

Y

Y

CCDOFSAB

commanded CCD bias offset for amps A\&B

I4

N

Y

CCDOFSCD

commanded CCD bias offset for amps C\&D

I4

N

Y

CCDOFSTA

commanded CCD bias offset for amplifier A

I4

Y

N

CCDOFSTB

commanded CCD bias offset for amplifier B

I4

Y

N

CCDOFSTC

commanded CCD bias offset for amplifier C

I4

Y

N

CCDOFSTD

commanded CCD bias offset for amplifier D

I4

Y

N

CALIBRATED ENGINEERING PARAMETERS





ATODGNA

measured gain for amplifier A

R4

Y

Y

ATODGNB

measured gain for amplifier B

R4

Y

Y

ATODGNC

measured gain for amplifier C

R4

Y

Y

ATODGND

measured gain for amplifier D

R4

Y

Y

READNSEA

measured read noise for amplifier A

R4

Y

Y

READNSEB

measured read noise for amplifier B

R4

Y

Y

READNSEC

measured read noise for amplifier C

R4

Y

Y

READNSED

measured read noise for amplifier D

R4

Y

Y

BIASLEVA

bias level for amplifier A

R4

Y

Y

BIASLEVB

bias level for amplifier B

R4

Y

Y

BIASLEVC

bias level for amplifier C

R4

Y

Y

BIASLEVD

bias level for amplifier D

R4

Y

Y

ASSOCIATION KEYWORDS





ASN_ID

unique identifier assigned to association

C10

Y

Y

ASN_TAB

name of the association table

C23

Y

Y

ASN_MTYP

role of the member in the association

C12

Y

Y


Table 2.9: WFC3 SCI extension header keywords 

KeywordDescriptionFormatUVISIR
XTENSION

extension type

C08

Y

Y

BITPIX

bits per data value

I2

Y

Y

NAXIS

number of data axes

I2

Y

Y

NAXIS1

length of first data axis

I4

Y

Y

NAXIS2

length of second data axis

I4

Y

Y

PCOUNT

number of group parameters

I2

Y

Y

GCOUNT

number of groups

I2

Y

Y

INHERIT

inherit the primary header

L1

Y

Y

EXTNAME

extension name

C08

Y

Y

EXTVER

extension version number

I2

Y

Y

ROOTNAME

rootname of the observation set

C34

Y

Y

EXPNAME

exposure identifier

C25

Y

Y

DATAMIN

the minimum value of the data

R8

Y

Y

DATAMAX

the maximum value of the data

R8

Y

Y

BUNIT

brightness units

C18

Y

Y

BSCALE

scale factor for array value to physical value

R8

Y

Y

BZERO

physical value for an array value of zero

R8

Y

Y

CCD CHIP IDENTIFICATION





CCDCHIP

CCD chip (1 or 2)

I2

Y

N

WORLD COORDINATE SYSTEM AND RELATED PARAMETERS





WCSAXES

number of World Coordinate System axes

I2

Y

Y

CRPIX1

xcoordinate of reference pixel

R8

Y

Y

CRPIX2

ycoordinate of reference pixel

R8

Y

Y

CRVAL1

first axis value at reference pixel

R8

Y

Y

CRVAL2

second axis value at reference pixel

R8

Y

Y

CTYPE1

the coordinate type for the first axis

C08

Y

Y

CTYPE2

the coordinate type for the second axis

C08

Y

Y

CD1_1

partial of first axis coordinate w.r.t. x

R8

Y

Y

CD1_2

partial of first axis coordinate w.r.t. y

R8

Y

Y

CD2_1

partial of second axis coordinate w.r.t. x

R8

Y

Y

CD2_2

partial of second axis coordinate w.r.t. y

R8

Y

Y

LTV1

offset in X to subsection start

R4

Y

Y

LTV2

offset in Y to subsection start

R4

Y

Y

LTM1_1

reciprocal of sampling rate in X

R4

Y

Y

LTM2_2

reciprocal of sampling rate in Y

R4

Y

Y

PA_APER

position Angle of reference aperture center (deg)

R8

Y

Y

VAFACTOR

velocity aberration plate scale factor

R8

Y

Y

ORIENTAT

position angle of image y axis (degrees East of North)

R4

Y

Y

RA_APER

right ascension of aperture reference position

R8

Y

Y

DEC_APER

declination of aperture reference position

R8

Y

Y

REPEATED EXPOSURES INFORMATION





NCOMBINE

number of image sets combined during CR rejection

I2

Y

Y

PHOTOMETRY KEYWORDS 
(contained in this extension for UVIS, in the primary extension for IR, see Table 2.8)





PHOTMODE

observation configuration for photometric calibration

C50

Y

N

PHOTFLAM

inverse sensitivity, ergs/cm2/Ang/electron

R8

Y

N

PHTFLAM1

PHOTFLAM on chip 1 when scales are not uniform

R8

Y

N

PHTFLAM2

PHOTFLAM on chip 2 when scales are not uniform

R8

Y

N

PHTRATIO

Ratio of PHTFLAM1/PHTFLAM2

R8

Y

N

PHOTFNU

inverse sensitivity, Jy*sec/electron

R8

Y

N

PHOTZPT

ST magnitude zero point

R4

Y

N

PHOTPLAM

pivot wavelength (Angstroms)

R4

Y

N

PHOTBW

RMS bandwidth of filter plus detector

R4

Y

N

READOUT DEFINITION PARAMETERS





CENTERA1

subarray axis1 center point in unbinned detector pix

I4

Y

Y

CENTERA2

subarray axis2 center point in unbinned detector pix

I4

Y

Y

SIZAXIS1

subarray axis1 size in unbinned detector pixels

I4

Y

Y

SIZAXIS2

subarray axis2 size in unbinned detector pixels

I4

Y

Y

BINAXIS1

axis1 data bin size in unbinned detector pixels

I2

Y

Y

BINAXIS2

axis2 data bin size in unbinned detector pixels

I2

Y

Y

READOUT PARAMETERS





SAMPNUM

MULTIACCUM sample number

I2

N

Y

SAMPTIME

total integration time (sec)

R4

N

Y

DELTATIM

integration time of this sample (sec)

R4

N

Y

ROUTTIME

UT time of array readout (MJD)

R8

N

Y

TDFTRANS

number of TDF transitions during current sample

I4

N

Y

DATA PACKET INFORMATION





FILLCNT

number of segments containing fill

I4

Y

Y

ERRCNT

number of segments containing errors

I4

Y

Y

PODPSFF

PODPS fill present (T/F)

L1

Y

Y

STDCFFF

science telemetry fill data present (T/F)

L1

Y

Y

STDCFFP

science telemetry fill pattern (hex)

C06

Y

Y

IMAGE STATISTICS AND DATA QUALITY FLAGS





NGOODPIX

number of good pixels

I4

Y

Y

SDQFLAGS

serious data quality flags

I4

Y

Y

GOODMIN

minimum value of good pixels

R4

Y

Y

GOODMAX

maximum value of good pixels

R4

Y

Y

GOODMEAN

mean value of good pixels

R4

Y

Y

SNRMIN

minimum signal to noise of good pixels

R4

Y

Y

SNRMAX

maximum signal to noise of good pixels

R4

Y

Y

NRMEAN

mean value of signal to noise of good pixels

R4

Y

Y

SOFTERRS

number of soft error pixels (DQF1)

I4

Y

Y

MEANDARK

average dark level subtracted

R4

Y

Y

MEANBLEV

average bias level subtracted

R4

Y

Y

MEANFLSH

mean number of counts in post flash exposure, DN/pixel

R4

Y

N


Table 2.10 : WFC3 extension header keywords (imset extensions 2-5)


 

 

 

Extension Type

Keyword

Description

Format

ERR

DQ

SAMP

TIME


 

 

 

(UVIS and IR)

(IR Only)

XTENSION

extension type

C08

Y

Y

Y

Y

NAXIS1

length of first data axis

I4

Y

Y

Y

Y

NAXIS2

length of second data axis

I4

Y

Y

Y

Y

PCOUNT

number of group parameters

I2

Y

Y

Y

Y

GCOUNT

number of groups

I2

Y

Y

Y

Y

TFIELDS

number of fields in each table row

I2

Y

Y

Y

Y

INHERIT

inherit the primary header

L1

Y

Y

Y

Y

EXTNAME

extension name

C08

Y

Y

Y

Y

EXTVER

extension version number

I2

Y

Y

Y

Y

ROOTNAME

rootname of the observation set

C34

Y

Y

Y

Y

EXPNAME

exposure identifier

C25

Y

Y

Y

Y

DATAMIN

the minimum value of the data

R8

Y

Y

Y

Y

DATAMAX

the maximum value of the data

R8

Y

Y

Y

Y

BUNIT

brightness units

C18

Y

Y

Y

Y

NPIX1

length of constant array axis 1

I4

Y

Y

Y

Y

NPIX2

length of constant array axis 2

I4

Y

Y

Y

Y

PIXVALUE

values of pixels in constant array

R4

Y

Y

Y

Y

WORLD COORDINATE SYSTEM AND RELATED PARAMETERS

WCSAXES

number of World Coordinate System axes

I2

Y

Y

Y

Y

CRPIX1

x-coordinate of reference pixel

R8

Y

Y

Y

Y

CRPIX2

y-coordinate of reference pixel

R8

Y

Y

Y

Y

CRVAL1

first axis value at reference pixel

R8

Y

Y

Y

Y

CRVAL2

second axis value at reference pixel

R8

Y

Y

Y

Y

CTYPE1

the coordinate type for the first axis

C08

Y

Y

Y

Y

CTYPE2

the coordinate type for the second axis

C08

Y

Y

Y

Y

CD1_1

partial of first axis coordinate w.r.t. x

R8

Y

Y

Y

Y

CD1_2

partial of first axis coordinate w.r.t. y

R8

Y

Y

Y

Y

CD2_1

partial of second axis coordinate w.r.t. x

R8

Y

Y

Y

Y

CD2_2

partial of second axis coordinate w.r.t. y

R8

Y

Y

Y

Y

LTV1

offset in X to subsection start

R4

Y

Y

-

-

LTV2

offset in Y to subsection start

R4

Y

Y

-

-

LTM1_1

reciprocal of sampling rate in X

R4

Y

Y

-

-

LTM2_2

reciprocal of sampling rate in Y

R4

Y

Y

-

-

PA_APER

position angle of reference aperture center (deg)

R8

Y

Y

-

-

VAFACTOR

velocity aberration plate scale factor

R8

Y

Y

-

-

IMAGE STATISTICS AND DATA QUALITY FLAGS

NGOODPIX

number of good pixels

I4

Y

-

-

-

SDQFLAGS

serious data quality flags

I4

Y

-

-

-

GOODMIN

minimum value of good pixels

R4

Y

-

-

-

GOODMAX

maximum value of good pixels

R4

Y

-

-

-

GOODMEAN

mean value of good pixels

R4

Y

-

-

-