| Summary: | Raw data from the two DESI Sky Cameras, with one fpack-compressed HDU for each camera. |
|---|---|
| Naming Convention: | sky-EXPID.fits.fz, where EXPID is the zero-padded
8-digit exposure ID. |
| Regex: | sky-[0-9]{8}\.fits\.fz |
| File Type: | FITS, 70 MB |
| Number | EXTNAME | Type | Contents |
|---|---|---|---|
| HDU0 | SKY | Empty HDU | Header keywords only |
| HDU1 | SKYCAM1 | Compressed IMAGE | Sky camera frames |
| HDU2 | SKYCAM1T | BINTABLE | Metadata about each frame |
| HDU3 | SKYCAM0 | Compressed IMAGE | Sky camera frames |
| HDU4 | SKYCAM0T | BINTABLE | Metadata about each frame |
The SKYCAMERA data will be 3D[nframes, ny, nx] such that
data[i] is the 2D sky camera frame number i. Row i of the
SKYCAM[01]T table will contain the metadata about that frame, e.g. the
DATE-OBS and EXPTIME.
EXTNAME = SKY
This HDU contains header keywords only.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ====================================================== ======= ===============================================
KEY Example Value Type Comment
======== ====================================================== ======= ===============================================
MODULE SKY str Image Sources/Component
EXPID 118526 int Exposure number
FRAMES 7 int Number of Frames in Archive
TILEID 4403 int DESI Tile ID
FLAVOR science str Observation type
PURPOSE Main Survey str Purpose of observing night
PROGRAM DARK str Program name
NIGHT 20220113 int Observing night
ACQTIME None Unknown [s] acqusition image exposure time
GUIDTIME None Unknown [s] guider GFA exposure time
FOCSTIME None Unknown [s] focus GFA exposure time
SKYTIME 60.0 float [s] sky camera exposure time (acquisition)
REQRA 170.239 float [deg] Requested right ascension (observer input
REQDEC -7.093 float [deg] Requested declination (observer input)
DELTARA None Unknown [arcsec] Offset], right ascension, observer inp
DELTADEC None Unknown [arcsec] Offset], declination, observer input
FOCUS 946.6,-231.6,-83.4,-18.3,9.8,139.4 str Telescope focus settings
TRUSTEMP 12.267 float [deg] Average Telescope truss temperature (only
PMIRTEMP 11.675 float [deg] Average primary mirror temperature (nit,e
SKYDEC -7.102329 float [deg] Telescope declination (pointing on sky)
SKYRA 170.24163 float [deg] Telescope right ascension (pointing on sk
TARGTDEC -7.102329 float [deg] Target declination (to TCS)
TARGTRA 170.24163 float [deg] Target right ascension (to TCS)
ACQCAM GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8 str Acquisition cameras used
GUIDECAM GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8 str Guide cameras used for t
FOCUSCAM FOCUS1,FOCUS4,FOCUS6,FOCUS9 str Focus cameras used for this exposure
SKYCAM SKYCAM0,SKYCAM1 str Sky cameras used for this exposure
ADC1PHI None Unknown [deg] ADC 1 angle
ADC2PHI None Unknown [deg] ADC 2 angle
HEXPOS None Unknown Hexapod position
DOSVER trunk str DOS software version
CONSTVER DESI:CURRENT str Constants version
ARCHIVE /exposures/desi/20220113/00118526/sky-00118526.fits.fz str
CHECKSUM 1m7R3m7P1m7P1m7P str HDU checksum updated 2022-01-14T11:14:08
DATASUM 0 str data unit checksum updated 2022-01-14T11:14:08
======== ====================================================== ======= ===============================================
Empty HDU.
EXTNAME = SKYCAM1
Contains the raw data from multiple exposures of SkyCam1, normally taken concurrently with a DESI spectrograph exposure.
Each raw image contains spots from the ETC fibers whose total flux is a measure of relative sky brightness in the r band.
Use the desietc.sky module to reduce these images and measure sky fiber fluxes.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ==================================================== ======= ===============================================
KEY Example Value Type Comment
======== ==================================================== ======= ===============================================
NAXIS1 8 int width of table in bytes
NAXIS2 14329 int number of rows in table
ZTILE3 1 int size of tiles to be compressed
BZERO 32768 int offset data range to that of unsigned short
BSCALE 1 int default scaling factor
EXPID 118526 int Exposure number
FRAMES 7 int Number of Frames in Archive
TILEID 4403 int DESI Tile ID
FIBASSGN /data/tiles/SVN_tiles/004/fiberassign-004403.fits.gz str Fiber assign
FLAVOR science str Observation type
SEQUENCE _Split str OCS Sequence name
PURPOSE Main Survey str Purpose of observing night
PROGRAM DARK str Program name
PROPID 2020B-5000 str Proposal ID
OBSERVER Jessica Chellino, Corentin Ravoux str Names of observers
LEAD Martin Landriau str Lead observer
INSTRUME DESI str Instrument name
OBSERVAT KPNO str Observatory name
OBS-LAT 31.96403 str [deg] Observatory latitude
OBS-LONG -111.59989 str [deg] Observatory east longitude
OBS-ELEV 2097.0 float [m] Observatory elevation
TELESCOP KPNO 4.0-m telescope str Telescope name
CORRCTOR DESI Corrector str Corrector Identification
NIGHT 20220113 int Observing night
TIMESYS UTC str Time system used for date-obs
DATE-OBS 2022-01-14T11:04:17.933414 str [UTC] Observation data and start time
MJD-OBS 59593.46131867 float Modified Julian Date of observation
ST 11:14:42.9462 str Local Sidereal time at observation start (HH:MM
SKYTIME 60.0 float [s] sky camera exposure time (acquisition)
REQRA 170.239 float [deg] Requested right ascension (observer input
REQDEC -7.093 float [deg] Requested declination (observer input)
DELTARA None Unknown [arcsec] Offset], right ascension, observer inp
DELTADEC None Unknown [arcsec] Offset], declination, observer input
FOCUS 946.6,-231.6,-83.4,-18.3,9.8,139.4 str Telescope focus settings
TRUSTEMP 12.267 float [deg] Average Telescope truss temperature (only
PMIRTEMP 11.675 float [deg] Average primary mirror temperature (nit,e
EPOCH 2000.0 float Epoch of observation
EQUINOX None Unknown Equinox of selected coordinate reference frame
MOUNTAZ 176.725567 float [deg] Mount azimuth angle
MOUNTDEC -7.102329 float [deg] Mount declination
MOUNTEL 50.883914 float [deg] Mount elevation angle
MOUNTHA -2.081118 float [deg] Mount hour angle
SKYDEC -7.102329 float [deg] Telescope declination (pointing on sky)
SKYRA 170.24163 float [deg] Telescope right ascension (pointing on sk
TARGTDEC -7.102329 float [deg] Target declination (to TCS)
TARGTRA 170.24163 float [deg] Target right ascension (to TCS)
USEETC T bool ETC data available if true
ACQCAM GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8 str Acquisition cameras used
GUIDECAM GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8 str Guide cameras used for t
FOCUSCAM FOCUS1,FOCUS4,FOCUS6,FOCUS9 str Focus cameras used for this exposure
SKYCAM SKYCAM0,SKYCAM1 str Sky cameras used for this exposure
ADC1PHI None Unknown [deg] ADC 1 angle
USESKY T bool DOS Control: use Sky Monitor
USEFOCUS T bool DOS Control: use focus
HEXPOS None Unknown Hexapod position
HEXTRIM 0.0,0.0,0.0,0.0,0.0,0.0 str Hexapod trim values
USEROTAT T bool DOS Control: use rotator
ROTOFFST 138.8 float [arcsec] Rotator offset
ROTENBLD T bool Rotator enabled
ROTRATE 0.513 float [arcsec/min] Rotator rate
USEGUIDR T bool DOS Control: use guider
USEDONUT T bool DOS Control: use donuts
RADESYS FK5 str Coordinate reference frame of major/minor axes
SHAPE 2047,3072 str
DOSVER trunk str DOS software version
OCSVER 1.2 float OCS software version
CONSTVER DESI:CURRENT str Constants version
INIFILE /data/msdos/dos_home/architectures/kpno/desi.ini str DOS Configuration
ADCPHI2 None Unknown
ROI None Unknown
ROIWIDTH None Unknown
GEXPMODE None Unknown GFA readout mode (loop/normal)
DEVICEID None Unknown GFA device id (serial number)
REQTIME 1860.0 float [s] Requested exposure time
CHECKSUM CPA0EN50CNA0CN30 str HDU checksum updated 2022-01-14T11:14:08
DATASUM 4223421838 str data unit checksum updated 2022-01-14T11:14:08
======== ==================================================== ======= ===============================================
Data: FITS image [int16 (compressed), 3072x2047x7]
EXTNAME = SKYCAM1T
A table of timestamps and instrument parameters for each SkyCam0 exposure stored in HDU SKYCAM1.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ================ ==== ==============================================
KEY Example Value Type Comment
======== ================ ==== ==============================================
NAXIS1 144 int width of table in bytes
NAXIS2 7 int number of rows in table
CHECKSUM S14XT04US04US04U str HDU checksum updated 2022-01-14T11:14:08
DATASUM 136958306 str data unit checksum updated 2022-01-14T11:14:08
======== ================ ==== ==============================================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| EXPTIME | float64 | TODO: description needed | |
| REQTIME [1] | float64 | TODO: description needed | |
| NIGHT | int64 | TODO: description needed | |
| DATE-OBS | char[26] | TODO: description needed | |
| TIME-OBS | char[15] | TODO: description needed | |
| MJD-OBS | float64 | TODO: description needed | |
| OPENSHUT | char[*] | TODO: description needed | |
| ST | char[*] | TODO: description needed | |
| HEXPOS | char[4] | TODO: description needed | |
| GAMBNTT | char[4] | TODO: description needed | |
| GFPGAT | char[4] | TODO: description needed | |
| GFILTERT | char[4] | TODO: description needed | |
| GCOLDTEC | char[4] | TODO: description needed | |
| GHOTTEC | char[4] | TODO: description needed | |
| GCCDTEMP | char[4] | TODO: description needed | |
| GCAMTEMP | char[4] | TODO: description needed | |
| GHUMID2 | char[4] | TODO: description needed | |
| GHUMID3 | char[4] | TODO: description needed |
| [1] | (1, 2) Optional |
EXTNAME = SKYCAM0
Contains the raw data from multiple exposures of SkyCam0, normally taken concurrently with a DESI spectrograph exposure.
Each raw image contains spots from the ETC fibers whose total flux is a measure of relative sky brightness in the r band.
Use the desietc.sky module to reduce these images and measure sky fiber fluxes.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ==================================================== ======= ===============================================
KEY Example Value Type Comment
======== ==================================================== ======= ===============================================
NAXIS1 8 int width of table in bytes
NAXIS2 14329 int number of rows in table
ZTILE3 1 int size of tiles to be compressed
BZERO 32768 int offset data range to that of unsigned short
BSCALE 1 int default scaling factor
EXPID 118526 int Exposure number
FRAMES 7 int Number of Frames in Archive
TILEID 4403 int DESI Tile ID
FIBASSGN /data/tiles/SVN_tiles/004/fiberassign-004403.fits.gz str Fiber assign
FLAVOR science str Observation type
SEQUENCE _Split str OCS Sequence name
PURPOSE Main Survey str Purpose of observing night
PROGRAM DARK str Program name
PROPID 2020B-5000 str Proposal ID
OBSERVER Jessica Chellino, Corentin Ravoux str Names of observers
LEAD Martin Landriau str Lead observer
INSTRUME DESI str Instrument name
OBSERVAT KPNO str Observatory name
OBS-LAT 31.96403 str [deg] Observatory latitude
OBS-LONG -111.59989 str [deg] Observatory east longitude
OBS-ELEV 2097.0 float [m] Observatory elevation
TELESCOP KPNO 4.0-m telescope str Telescope name
CORRCTOR DESI Corrector str Corrector Identification
NIGHT 20220113 int Observing night
TIMESYS UTC str Time system used for date-obs
DATE-OBS 2022-01-14T11:04:17.933414 str [UTC] Observation data and start time
MJD-OBS 59593.46131867 float Modified Julian Date of observation
ST 11:14:42.9462 str Local Sidereal time at observation start (HH:MM
SKYTIME 60.0 float [s] sky camera exposure time (acquisition)
REQRA 170.239 float [deg] Requested right ascension (observer input
REQDEC -7.093 float [deg] Requested declination (observer input)
DELTARA None Unknown [arcsec] Offset], right ascension, observer inp
DELTADEC None Unknown [arcsec] Offset], declination, observer input
FOCUS 946.6,-231.6,-83.4,-18.3,9.8,139.4 str Telescope focus settings
TRUSTEMP 12.267 float [deg] Average Telescope truss temperature (only
PMIRTEMP 11.675 float [deg] Average primary mirror temperature (nit,e
EPOCH 2000.0 float Epoch of observation
EQUINOX None Unknown Equinox of selected coordinate reference frame
MOUNTAZ 176.725567 float [deg] Mount azimuth angle
MOUNTDEC -7.102329 float [deg] Mount declination
MOUNTEL 50.883914 float [deg] Mount elevation angle
MOUNTHA -2.081118 float [deg] Mount hour angle
SKYDEC -7.102329 float [deg] Telescope declination (pointing on sky)
SKYRA 170.24163 float [deg] Telescope right ascension (pointing on sk
TARGTDEC -7.102329 float [deg] Target declination (to TCS)
TARGTRA 170.24163 float [deg] Target right ascension (to TCS)
USEETC T bool ETC data available if true
ACQCAM GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8 str Acquisition cameras used
GUIDECAM GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8 str Guide cameras used for t
FOCUSCAM FOCUS1,FOCUS4,FOCUS6,FOCUS9 str Focus cameras used for this exposure
SKYCAM SKYCAM0,SKYCAM1 str Sky cameras used for this exposure
ADC1PHI None Unknown [deg] ADC 1 angle
USESKY T bool DOS Control: use Sky Monitor
USEFOCUS T bool DOS Control: use focus
HEXPOS None Unknown Hexapod position
HEXTRIM 0.0,0.0,0.0,0.0,0.0,0.0 str Hexapod trim values
USEROTAT T bool DOS Control: use rotator
ROTOFFST 138.8 float [arcsec] Rotator offset
ROTENBLD T bool Rotator enabled
ROTRATE 0.513 float [arcsec/min] Rotator rate
USEGUIDR T bool DOS Control: use guider
USEDONUT T bool DOS Control: use donuts
RADESYS FK5 str Coordinate reference frame of major/minor axes
SHAPE 2047,3072 str
DOSVER trunk str DOS software version
OCSVER 1.2 float OCS software version
CONSTVER DESI:CURRENT str Constants version
INIFILE /data/msdos/dos_home/architectures/kpno/desi.ini str DOS Configuration
ADCPHI2 None Unknown
ROI None Unknown
ROIWIDTH None Unknown
GEXPMODE None Unknown GFA readout mode (loop/normal)
DEVICEID None Unknown GFA device id (serial number)
REQTIME 1860.0 float [s] Requested exposure time
CHECKSUM SLfNTKfKSKfKSKfK str HDU checksum updated 2022-01-14T11:14:09
DATASUM 4278834758 str data unit checksum updated 2022-01-14T11:14:09
======== ==================================================== ======= ===============================================
Data: FITS image [int16 (compressed), 3072x2047x7]
EXTNAME = SKYCAM0T
A table of timestamps and instrument parameters for each SkyCam0 exposure stored in HDU SKYCAM0.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ================ ==== ==============================================
KEY Example Value Type Comment
======== ================ ==== ==============================================
NAXIS1 144 int width of table in bytes
NAXIS2 7 int number of rows in table
CHECKSUM dFIceCHbdCHbdCHb str HDU checksum updated 2022-01-14T11:14:09
DATASUM 3066928412 str data unit checksum updated 2022-01-14T11:14:09
======== ================ ==== ==============================================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| EXPTIME | float64 | TODO: description needed | |
| REQTIME [1] | float64 | TODO: description needed | |
| NIGHT | int64 | TODO: description needed | |
| DATE-OBS | char[26] | TODO: description needed | |
| TIME-OBS | char[15] | TODO: description needed | |
| MJD-OBS | float64 | TODO: description needed | |
| OPENSHUT | char[*] | TODO: description needed | |
| ST | char[*] | TODO: description needed | |
| HEXPOS | char[4] | TODO: description needed | |
| GAMBNTT | char[4] | TODO: description needed | |
| GFPGAT | char[4] | TODO: description needed | |
| GFILTERT | char[4] | TODO: description needed | |
| GCOLDTEC | char[4] | TODO: description needed | |
| GHOTTEC | char[4] | TODO: description needed | |
| GCCDTEMP | char[4] | TODO: description needed | |
| GCAMTEMP | char[4] | TODO: description needed | |
| GHUMID2 | char[4] | TODO: description needed | |
| GHUMID3 | char[4] | TODO: description needed |