- 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.
Required Header Keywords Table
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 ARCHIVE |
DESI:CURRENT /exposures/desi/20220113/00118526/sky-00118526.fits.fz |
str str |
Constants version |
| CHECKSUM | 1m7R3m7P1m7P1m7P | str | HDU checksum updated 2022-01-14T11:14:08 |
| DATASUM |
|
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.
Required Header Keywords Table
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 SHAPE |
FK5 2047,3072 |
str str |
Coordinate reference frame of major/minor axes |
| DOSVER | trunk | str | DOS software version |
| OCSVER | 1.2 | float | OCS software version |
| CONSTVER | DESI:CURRENT | str | Constants version |
INIFILE ADCPHI2 ROI ROIWIDTH |
/data/msdos/dos_home/architectures/kpno/desi.ini None None None |
str Unknown Unknown Unknown |
DOS Configuration |
| 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.
Required Header Keywords Table
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 |
columns
| Name | Type | Units | Description |
|---|---|---|---|
EXPTIME REQTIME1 NIGHT DATE-OBS TIME-OBS MJD-OBS OPENSHUT ST HEXPOS GAMBNTT GFPGAT GFILTERT GCOLDTEC GHOTTEC GCCDTEMP GCAMTEMP GHUMID2 GHUMID3 |
float64 float64 int64 char[26] char[15] float64 char[] char[] char[4] char[4] char[4] char[4] char[4] char[4] char[4] char[4] char[4] char[4] |
TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed |
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.
Required Header Keywords Table
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 SHAPE |
FK5 2047,3072 |
str str |
Coordinate reference frame of major/minor axes |
| DOSVER | trunk | str | DOS software version |
| OCSVER | 1.2 | float | OCS software version |
| CONSTVER | DESI:CURRENT | str | Constants version |
INIFILE ADCPHI2 ROI ROIWIDTH |
/data/msdos/dos_home/architectures/kpno/desi.ini None None None |
str Unknown Unknown Unknown |
DOS Configuration |
| 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.
Required Header Keywords Table
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 |
columns
| Name | Type | Units | Description |
|---|---|---|---|
EXPTIME REQTIME2 NIGHT DATE-OBS TIME-OBS MJD-OBS OPENSHUT ST HEXPOS GAMBNTT GFPGAT GFILTERT GCOLDTEC GHOTTEC GCCDTEMP GCAMTEMP GHUMID2 GHUMID3 |
float64 float64 int64 char[26] char[15] float64 char[] char[] char[4] char[4] char[4] char[4] char[4] char[4] char[4] char[4] char[4] char[4] |
TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed TODO: description needed |