FITS headers & other metadata
DocDB #1184:
“Dark Energy Survey Data Management: Data Products”
By Joe Mohr, et al.
describes the metadata, including the FITS headers.
SISPI (the Image Builder) will fill the FITS headers according to this
specification. Other metadata will be stored in the facility DB, which
will be synchronized with the repository databases.
NB: We have not yet figured out the logistics for acquiring all the
information in a timely manner.
9/12/08
Jon Thaler
1
Table 2-3:
Keyword
SIMPLE
BITPIX
NAXIS
EXTEND
NEXTEND
FILENAME
EXPNUM
OBJECT
OBSTYPE
OBSERVER
PROPID
DETECTOR
DETSIZE
TELESCOP
OBSERVAT
LATITUDE
LONGITUD
ALTITUDE
TELRADEC
TELEQUIN
TELRA
TELDEC
Type
Logical
Integer
Integer
Logical
Integer
String
Integer
String
String
String
String
String
String
String
String
String
String
Float
String
Float
String
String
9/12/08
DECam Exposure 0 Extension Header
Example
Comment
T
File conforms to FITS standard
8
Number of bits per data pixel
0
Number of data axes
T
May contain extensions
62
Number of extensions
decam-2006-10-06-40141298.fits
452893
DECam exposure number
DES0550-2116A Object name
object
Observation type
John Peoples Observer Name
2006B-0569
Proposal ID
decam
Detector
[1:24576,1:28672]
Detector size
ct4m
Telescope Name
CTIO
Observatory Name
-30:09:54
Observatory Latitude (deg)
70:49:00 W
Observatory Longitude (deg)
2215.0
Observatory Altitude (m)
FK5
Telescope coordinate system
2000.0
Equinox of telescope coords
00:21:16.92 Telescope RA (hr)
-48:39:43.6 Telescope Dec (deg)
Keyword
HA
ZD
AIRMASS
FILTER
TELFOCUS
TIMESYS
DATE-OBS
TIME-OBS
MJD-OBS
EXPTIME
EXPREQ
DARKTIME
EPOCH
WINDSPD
WINDDIR
AMBTEMP
HUMIDITY
PRESSURE
SKYVAR
FLUXVAR
CHECKSUM
CHECKVER
IMAGEHWV
IMAGESWV
Jon Thaler
Type
String
Float
Float
String
Integer
String
String
String
Double
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
String
String
String
String
Example
Comment
02:09:18.7
Telescope hour angle (hr)
30.7
Telescope zenith distance (deg)
1.162
Airmass
g SDSS c6017
Filter name
16688
Telescope focus
UTC approximate Time system
2006-09-05
Date of observation start
08:17:3.988
Time of observation start
53983.34519
MJD of observation start
354.43
Exposure time (s)
360.00
Exposure time request (s)
359.34
Dark time (s)
2007.054
Epoch of observation
5.4
Wind speed (mph)
24
Wind direction (deg)
11.9
Ambient temperature (deg C)
16
Ambient relative humidity (%)
783
Barometric pressure (mbar)
2.54
Sky variation from IR camera (%)
0.51
Guide star flux variation (5)
0WDA3T940TA90T99 Header Checksum
complement
Checksum software version
SISPI hw 1.2.3.4 SISPI Hardware Version
SISPI sw 4.3.2.1 SISPI Software Version
2
Table 2-4:
Keyword
XTENSION
SIMPLE
BITPIX
BZERO
BSCALE
NAXIS
NAXIS1
NAXIS2
EXTEND
INHERIT
CCDNAME
CCDNUM
DETSEC
CCDSUM
DATASEC
TRIMSEC
AMPSECA
BIASSECA
GAINA
RDNOISEA
SATURATEA
AMPSECB
BIASSECB
GAINB
RDNOISEB
SATURATEB
EQUINOX
WCSDIM
CTYPE1
CTYPE2
CRVAL1
CRVAL2
CRPIX1
CRPIX2
Type
String
Logical
Long
Long
Long
Long
Long
Long
Logical
Logical
String
Long
String
String
String
String
String
String
Float
Float
Float
String
String
Float
Float
Float
Float
Long
String
String
Double
Double
Double
Double
9/12/08
DECam Exposure Header for Image Extensions (1-62)
Example
Comment
IMAGE
Extension type
T
Conforms to FITS standard
16
Number of bits per data pixel
32768
Zero shift for unsigned short
1
Scale factor for unsigned short
2
Number of data axes
2104
Length of axis 1
4096
Length of axis 2
T
May contain extensions
T
Inherits global header
FNAL #9817eFABR14-08 CCD Name
1
CCD Number
[1:2048,1:4096] Detector Section
1 1
CCD pixel summing
[51:2098,1:4096] Data Section of CCD
[51:2098,1:4096] Trim Section of CCD
[1:1024,1:4096] Amp A Section
[1:50,1:4096] BIAS Section for Amp A
2.7
Gain for Amp A
7.8
Read Noise for Amp A
40000.0
Saturation for Amp A
[1025:2048,1:4096] Amp B Section
[2098:2148,1:4096] BIAS Section for Amp B
2.7
Gain for Amp B
7.8
Read Noise for Amp B
40000.0
Saturation for Amp B
2000.0
Equinox of WCS
2
WCS Dimensionality
RA---TAN
Coordinate Type
DEC--TAN
Coordinate Type
356.759700000 Coordinate Reference Value
-43.749901000 Coordinate Reference Value
13240.2333710 Coordinate Reference Pixel
6274.06658936 Coordinate Reference Pixel
Keyword
CD1_2
CD2_1
CD2_2
PV1_0
PV1_1
PV1_2
PV1_3
PV1_4
PV1_5
PV1_6
PV1_7
PV1_8
PV1_9
PV1_10
PV2_0
PV2_1
PV2_2
PV2_3
PV2_4
PV2_5
PV2_6
PV2_7
PV2_8
PV2_9
PV2_10
CHECKSUM
DATASUM
CHECKVER
Jon Thaler
Type
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
Float
String
String
String
Example
Comment
9.511111E-07 Coordinate Matrix
9.511111E-07 Coordinate Matrix
7.500000E-05 Coordinate Matrix
0.000000
PV Distortion Coefficient
1.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.002000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.002000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
1.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.002000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0.002000
PV Distortion Coefficient
0.000000
PV Distortion Coefficient
0WDA3T940TA90T99
Header checksum
0WDA3T940TA90T99
Data checksum
complement
Checksum version
3