guide-EXPID

Summary:

Raw data from the 6 in-focus GFA cameras captured during a DESI spectrograph exposure.

Naming Convention:

guide-EXPID.fits.fz, where EXPID is the zero-padded 8-digit exposure ID. Sometimes EXPID takes the form EXPID-0000. Sometimes the .fz is missing.

Regex:

guide-[0-9]{8}(-[0-9]{4})?\.fits(\.fz)?

File Type:

FITS, 732 MB

Contents

Number	EXTNAME	Type	Contents
HDU00	GUIDER	Empty HDU	Header keywords only
HDU01	PMGSTARS	BINTABLE	PlateMaker star table
HDU02	GUIDE5	Compressed IMAGE	GUIDE5 image cube
HDU03	GUIDE5T	BINTABLE	GUIDE5 image cube metadata
HDU04	GUIDE3	Compressed IMAGE	GUIDE3 image cube
HDU05	GUIDE3T	BINTABLE	GUIDE3 image cube metadata
HDU06	GUIDE2	Compressed IMAGE	GUIDE2 image cube
HDU07	GUIDE2T	BINTABLE	GUIDE2 image cube metadata
HDU08	GUIDE7	Compressed IMAGE	GUIDE7 image cube
HDU09	GUIDE7T	BINTABLE	GUIDE7 image cube metadata
HDU10	GUIDE8	Compressed IMAGE	GUIDE8 image cube
HDU11	GUIDE8T	BINTABLE	GUIDE8 image cube metadata
HDU12	GUIDE0	Compressed IMAGE	GUIDE0 image cube
HDU13	GUIDE0T	BINTABLE	GUIDE0 image cube metadata

GFA raw data is used to acuquire a new field, guide the telescope, determine the mapping from sky coordinates to focal-plane coordinates, and estimate the accumulated signal to noise in the spectrographs.

One option for reducing GFA raw data is to use the desietc.gfa module.

The GUIDEn data will be 3D[nframes, ny, nx] such that data[i] is the 2D GFA frame number i. Row i of the GUIDEnT table will contain the metadata about that frame, for example the DATE-OBS and EXPTIME. The image cubes include the overscan and prescan; nx is 2248 and ny is 1032. The active image area is 2048 by 1032 pixels once overscan and prescan have been removed.

Note that other than the blank data primary HDU, the order of the other HDUs is arbitrary and some GUIDEn(T) HDUs may even be missing. The nominal set (0,2,3,5,7,8) is the plan for full DESI, but particularly during commissioning other subsets will appear in the data. Also note that the acquisition image is frame i = 0 when there is an acquisition image (a sequence=DESI exposure has an acquisition image but a sequence=_Split exposure does not, for example).

Other than the name and number of the HDUs, the structure of this format is identical to the focus GFA raw data.

FITS Header Units

HDU00

EXTNAME = GUIDER

Blank data HDU with a header that contains a lot of exposure-level metadata.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
MODULE	GUIDE	str	Image Sources/Component
EXPID	118526	int	Exposure number
FRAMES	72	int	Number of Frames in Archive
COSMSPLT	F	bool	Cosmics split exposure if true
MAXSPLIT	0	int	Number of allowed exposure splits
VISITIDS	118524	str	List of expids for a visit (same tile)
TILEID	4403	int	DESI Tile ID
FIBASSGN	/data/tiles/SVN_tiles/004/fiberassign-004403.fits.gz	str	Fiber assign
FLAVOR	science	str	Observation type
OBSTYPE	SCIENCE	str	Spectrograph observation type
SEQUENCE	DESI	str	OCS Sequence name
MANIFEST	F	bool	DOS exposure manifest
OBJECT		str	Object name
PURPOSE	Main Survey	str	Purpose of observing night
PROGRAM	DARK	str	Program name
NTSSURVY	main	str	NTS survey name
NTSPROG	DARK	str	NTS program name
SBPROF	ELG	str	Profile used by ETC
MAXTIME	5400.0	float	[s] Maximum exposure time for entire visit (fro
ESTTIME	3705.79	float	[s] Estimated exposure time for visit (from ETC
MINTIME	300.0	float	[s] Minimum exposure time (from NTS, used by ET
MIDTIME	915.0	float	[s] Exposure midpoint time used by PlateMaker
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
SEQNUM	1	int	Number of exposure in sequence
NIGHT	20220113	int	Observing night
SEQSTART	2022-01-14T10:13:58.576904	str	Start time of sequence processing
TIMESYS	UTC	str	Time system used for date-obs
DATE-OBS	2022-01-14T11:03:58.319124	str	[UTC] Observation data and start time
MJD-OBS	59593.46109166	float	Modified Julian Date of observation
STARTADJ	2022-01-14T10:14:26.234369	str	Time sequence starts adjusting the inst
OPENSHUT	2022-01-14T11:03:58.319124	str	Time shutter opened
CAMSHUT	open	str	Shutter status during observation
ST	11:13:16.9528	str	Local Sidereal time at observation start (HH:MM
EXPTIME	5.0	float	[s] Actual exposure time
ACQTIME	15.0	float	[s] acqusition image exposure time
GUIDTIME	5.0	float	[s] guider GFA exposure time
FOCSTIME	60.0	float	[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
WHITESPT	F	bool	Telescope is at whitespot
ZENITH	F	bool	Telescope is at zenith
SEANNEX	F	bool	Telescope is at SE annex
BEYONDP	F	bool	Telescope is beyond pole
AIRMASS	1.331363	float	Airmass
FOCUS	948.5,-231.1,-91.3,-18.3,10.0,126.3	str	Telescope focus settings
VCCD	ON	str	True (ON) if CCD voltage is on
TRUSTEMP	12.4	float	[deg] Average Telescope truss temperature (only
PMIRTEMP	11.662	float	[deg] Average primary mirror temperature (nit,e
PMREADY	T	bool	Primary mirror ready
PMCOVER	open	str	Primary mirror cover
PMCOOL	off	str	Primary mirror cooling
DOMSHUTU	open	str	Upper dome shutter
DOMSHUTL	open	str	Lower dome shutter
DOMLIGHH	off	str	High dome lights
DOMLIGHL	off	str	Low dome lights
DOMEAZ	165.277	float	[deg] Dome azimuth angle
DOMINPOS	T	bool	Dome is in position
EPOCH	2000.0	float	Epoch of observation
GUIDOFFR	0.0	float	[arcsec] Cummulative guider offset (RA)
GUIDOFFD	-0.0	float	[arcsec] Cummulative guider offset (dec)
SUNRA	296.113998	float	[deg] Sun RA at start of exposure
SUNDEC	-21.270133	float	[deg] Sun declination at start of exposure
MOONDEC	23.881736	float	[deg] Moon declination at start of exposure
MOONRA	73.512629	float	[deg] Moon RA at start of exposure
MOONSEP	99.425	float	[deg] Moon Separation
SLEWANGL	5.795	float	[deg] Slew Angle
SLEWTIME	31.341	float	[s] Slew Time
MOUNTAZ	158.328478	float	[deg] Mount azimuth angle
MOUNTDEC	-7.10233	float	[deg] Mount declination
MOUNTEL	48.640103	float	[deg] Mount elevation angle
MOUNTHA	-14.235346	float	[deg] Mount hour angle
INCTRL	T	bool	DESI in control
INPOS	T	bool	Mount in position
MNTOFFD	-0.0	float	[arcsec] Mount offset (dec)
MNTOFFR	-0.0	float	[arcsec] Mount offset (RA)
PARALLAC	-18.404235	float	[deg] Parallactic angle
SKYDEC	-7.10233	float	[deg] Telescope declination (pointing on sky)
SKYRA	170.241629	float	[deg] Telescope right ascension (pointing on sk
TARGTDEC	-7.10233	float	[deg] Target declination (to TCS)
TARGTRA	170.241629	float	[deg] Target right ascension (to TCS)
TARGTAZ	158.328478	float	[deg] Target azimuth
TARGTEL	48.640103	float	[deg] Target elevation
TRGTOFFD	0.0	float	[arcsec] Telescope target offset (dec)
TRGTOFFR	0.0	float	[arcsec] Telescope target offset (RA)
ZD	41.359897	float	[deg] Telescope zenith distance
TILERA	170.239	float	RA of tile given in fiberassign file
TILEDEC	-7.093	float	DEC of tile given in fiberassign file
TCSST	10:24:01.508	str	Local Sidereal time reported by TCS (HH:MM:SS)
TCSMJD	59593.427501	float	MJD reported by TCS
USETURB	T	bool	Turbulence corrections are applied if true
USEETC	T	bool	ETC data available if true
SEEING	None	Unknown	[arcsec] ETC/PM seeing
TRANSPAR	None	Unknown	ETC/PM transparency
SKYLEVEL	4.036	float	[unit?] PM/ETC sky level
PMSEEING	None	Unknown	[arcsec] PlateMaker GFAPROC seeing
PMTRANSP	None	Unknown	[%] PlateMaker GFAPROC transparency
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
REQADC	316.38,12.3	str	[deg] requested ADC angles
ADCCORR	T	bool	Correct pointing for ADC setting if True
ADC1PHI	316.380005	float	[deg] ADC 1 angle
ADC2PHI	12.300831	float	[deg] ADC 2 angle
ADC1HOME	F	bool	ADC 1 at home position if True
ADC2HOME	F	bool	ADC 2 at home position if True
ADC1NREV	-1.0	float	ADC 1 number of revs
ADC2NREV	1.0	float	ADC 2 number of revs
ADC1STAT	STOPPED	str	ADC 1 status
ADC2STAT	STOPPED	str	ADC 2 status
USESKY	T	bool	DOS Control: use Sky Monitor
USEFOCUS	T	bool	DOS Control: use focus
HEXPOS	948.5,-231.1,-91.3,-18.3,10.0,126.3	str	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	121.0	float	[arcsec] Rotator offset
ROTENBLD	T	bool	Rotator enabled
ROTRATE	0.0	float	[arcsec/min] Rotator rate
RESETROT	F	bool	DOS Control: reset hex rotator
SPLITEXP	F	bool	Split exposure part of a visit
USESPLIT	T	bool	Exposure splits are allowed
USEPOS	T	bool	Fiber positioner data available if true
PETALS	PETAL0,PETAL1,PETAL2,PETAL3,PETAL4,PETAL5,PETAL6,PETAL7,PETAL8,PETAL9	str	Participating petals
USEGUIDR	T	bool	DOS Control: use guider
GUIDMODE	catalog	str	Guider mode
USEDONUT	T	bool	DOS Control: use donuts
USESPCTR	T	bool	DOS Control: use spectrographs
SPCGRPHS	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str	Participating spectrograph
ILLSPECS	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str	Participating illuminate s
CCDSPECS	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str	Participating ccd spectrog
TDEWPNT	-33.473	float	Telescope air dew point
TAIRFLOW	0.0	float	Telescope air flow
TAIRITMP	12.7	float	[deg] Telescope air in temperature
TAIROTMP	12.8	float	[deg] Telescope air out temperature
TAIRTEMP	11.3	float	[deg] Telescope air temperature
TCASITMP	6.6	float	[deg] Telescope Cass Cage in temperature
TCASOTMP	12.3	float	[deg] Telescope Cass Cage out temperature
TCSITEMP	12.1	float	[deg] Telescope center section in temperature
TCSOTEMP	12.2	float	[deg] Telescope center section out temperature
TCIBTEMP	0.0	float	[deg] Telescope chimney IB temperature
TCIMTEMP	0.0	float	[deg] Telescope chimney IM temperature
TCITTEMP	0.0	float	[deg] Telescope chimney IT temperature
TCOSTEMP	0.0	float	[deg] Telescope chimney OS temperature
TCOWTEMP	0.0	float	[deg] Telescope chimney OW temperature
TDBTEMP	12.3	float	[deg] Telescope dec bore temperature
TFLOWIN	0.0	float	Telescope flow rate in
TFLOWOUT	0.0	float	Telescope flow rate out
TGLYCOLI	12.9	float	[deg] Telescope glycol in temperature
TGLYCOLO	12.6	float	[deg] Telescope glycol out temperature
THINGES	12.3	float	[deg] Telescope hinge S temperature
THINGEW	22.3	float	[deg] Telescope hinge W temperature
TPMAVERT	11.695	float	[deg] Telescope mirror averagetemperature
TPMDESIT	6.0	float	[deg] Telescope mirror desired temperature
TPMEIBT	12.2	float	[deg] Telescope mirror EIB temperature
TPMEITT	11.5	float	[deg] Telescope mirror EIT temperature
TPMEOBT	12.3	float	[deg] Telescope mirror EOB temperature
TPMEOTT	12.0	float	[deg] Telescope mirror EOT temperature
TPMNIBT	12.0	float	[deg] Telescope mirror NIB temperature
TPMNITT	11.4	float	[deg] Telescope mirror NIT temperature
TPMNOBT	12.3	float	[deg] Telescope mirror NOB temperature
TPMNOTT	12.0	float	[deg] Telescope mirror NOT temperature
TPMRTDT	11.68	float	[deg] Telescope mirror RTD temperature
TPMSIBT	12.1	float	[deg] Telescope mirror SIB temperature
TPMSITT	11.5	float	[deg] Telescope mirror SIT temperature
TPMSOBT	12.1	float	[deg] Telescope mirror SOB temperature
TPMSOTT	11.8	float	[deg] Telescope mirror SOT temperature
TPMSTAT	ready	str	Telescope mirror status
TPMWIBT	11.9	float	[deg] Telescope mirror WIB temperature
TPMWITT	11.3	float	[deg] Telescope mirror WIT temperature
TPMWOBT	11.9	float	[deg] Telescope mirror WOB temperature
TPMWOTT	11.8	float	[deg] Telescope mirror WOT temperature
TPCITEMP	12.1	float	[deg] Telescope primary cell in temperature
TPCOTEMP	12.1	float	[deg] Telescope primary cell out temperature
TPR1HUM	0.0	float	Telescope probe 1 humidity
TPR1TEMP	0.0	float	[deg] Telescope probe1 temperature
TPR2HUM	0.0	float	Telescope probe 2 humidity
TPR2TEMP	0.0	float	[deg] Telescope probe2 temperature
TSERVO	40.0	float	Telescope servo setpoint
TTRSTEMP	12.1	float	[deg] Telescope top ring S temperature
TTRWTEMP	12.0	float	[deg] Telescope top ring W temperature
TTRUETBT	-1.5	float	[deg] Telescope truss ETB temperature
TTRUETTT	11.7	float	[deg] Telescope truss ETT temperature
TTRUNTBT	11.7	float	[deg] Telescope truss NTB temperature
TTRUNTTT	11.7	float	[deg] Telescope truss NTT temperature
TTRUSTBT	11.7	float	[deg] Telescope truss STB temperature
TTRUSTST	10.8	float	[deg] Telescope truss STS temperature
TTRUSTTT	11.9	float	[deg] Telescope truss STT temperature
TTRUTSBT	12.4	float	[deg] Telescope truss TSB temperature
TTRUTSMT	12.5	float	[deg] Telescope truss TSM temperature
TTRUTSTT	12.3	float	[deg] Telescope truss TST temperature
TTRUWTBT	11.6	float	[deg] Telescope truss WTB temperature
TTRUWTTT	11.7	float	[deg] Telescope truss WTT temperature
ALARM	F	bool	UPS major alarm or check battery
ALARM-ON	F	bool	UPS active alarm condition
BATTERY	100.0	float	[%] UPS Battery left
SECLEFT	5904.0	float	[s] UPS Seconds left
UPSSTAT	System Normal - On Line(7)	str	UPS Status
INAMPS	72.1	float	[A] UPS total input current
OUTWATTS	4900.0,7600.0,4600.0	str	[W] UPS Phase A, B, C output watts
COMPDEW	-10.4	float	[deg C] Computer room dewpoint
COMPHUM	14.1	float	[%] Computer room humidity
COMPAMB	25.2	float	[deg C] Computer room ambient temperature
COMPTEMP	17.3	float	[deg C] Computer room hygrometer temperature
DEWPOINT	-36.9	float	[deg C] (outside) dewpoint
HUMIDITY	1.6	float	[%] (outside) humidity
PRESSURE	793.6	float	[torr] (outside) air pressure
OUTTEMP	11.0	float	[deg C] outside temperature
WINDDIR	252.9	float	[deg] wind direction
WINDSPD	10.7	float	[m/s] wind speed
GUST	13.0	float	[m/s] Wind gusts speed
AMNIENTN	16.8	float	[deg C] ambient temperature north
CFLOOR	11.6	float	[deg C] temperature on C floor
NWALLIN	17.3	float	[deg C] temperature at north wall inside
NWALLOUT	11.1	float	[deg C] temperature at north wall outside
WWALLIN	16.6	float	[deg C] temperature at west wall inside
WWALLOUT	11.5	float	[deg C] temperature at west wall outside
AMBIENTS	17.6	float	[deg C] ambient temperature south
FLOOR	15.8	float	[deg C] temperature at floor (LCR)
EWALLCMP	11.9	float	[deg C] temperature at east wall, computer room
EWALLCOU	11.6	float	[deg C] temperature at east wall, Coude room
ROOF	11.0	float	[deg C] temperature on roof
ROOFAMB	11.3	float	[deg C] ambient temperature on roof
DOMEBLOW	11.2	float	[deg C] temperature at dome back, lower
DOMEBUP	11.3	float	[deg C] temperature at dome back, upper
DOMELLOW	11.2	float	[deg C] temperature at dome left, lower
DOMELUP	11.1	float	[deg C] temperature at dome left, upper
DOMERLOW	11.1	float	[deg C] temperature at dome right, lower
DOMERUP	10.8	float	[deg C] temperature at dome right, upper
PLATFORM	10.8	float	[deg C] temperature at platform
SHACKC	16.6	float	[deg C] temperature at shack ceiling
SHACKW	16.7	float	[deg C] temperature at shack wall
STAIRSL	11.2	float	[deg C] temperature at stairs, lower
STAIRSM	11.0	float	[deg C] temperature at stairs, mid
STAIRSU	11.1	float	[deg C] temperature at stairs, upper
TELBASE	11.7	float	[deg C] temperature at telescope base
UTILWALL	11.4	float	[deg C] temperature at utility room wall
UTILROOM	10.3	float	[deg C] temperature in utilitiy room
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
TNFSPROC	7.9838	float	[s] PlateMaker NFSPROC processing time
SIMGFAP	F	bool	DOS Control: simulate GFAPROC
USEFVC	T	bool	DOS Control: use fvc
USEFID	T	bool	DOS Control: use fiducials
USEILLUM	T	bool	DOS Control: use illuminator
USEXSRVR	T	bool	DOS Control: use exposure server
USEOPENL	T	bool	DOS Control: use open loop move
USEMIDPT	T	bool	Use exposure midpoint if true
STOPGUDR	T	bool	DOS Control: stop guider
STOPFOCS	T	bool	DOS Control: stop focus
STOPSKY	T	bool	DOS Control: stop sky monitor
KEEPGUDR	F	bool	DOS Control: keep guider running
KEEPFOCS	F	bool	DOS Control: keep focus running
KEEPSKY	F	bool	DOS Control: keep sky mon. running
REACQUIR	F	bool	DOS Control: reacquire same files
EXCLUDED		str	Components excluded from this exposure
DOSVER	trunk	str	DOS software version
OCSVER	1.2	float	OCS software version
PMVER	desi-138368	str	PlateMaker/Dervish version
CONSTVER	DESI:CURRENT	str	Constants version
INIFILE	/data/msdos/dos_home/architectures/kpno/desi.ini	str	DOS Configuration
REQTIME	1860.0	float	[s] Requested exposure time
SIMGFACQ	F	bool
TCSKRA	0.01 0.04 0.01	str	TCS Kalman (RA)
TCSKDEC	0.01 0.04 0.01	str	TCS Kalman (dec)
TCSGRA	0.15	float	TCS simple gain (RA)
TCSGDEC	0.15	float	TCS simple gain (dec)
TCSMFRA	2	int	TCS moving filter length (RA)
TCSMFDEC	2	int	TCS moving filter length (dec)
TCSPIRA	0.9,0.0,0.0,0.0	str	TCS PI settings (P, I (gain, error window, satu
TCSPIDEC	0.9,0.0,0.0,0.0	str	TCS PI settings (P, I (gain, error window, satu
GSGUIDE2	(664.34,38.87)	str
GSGUIDE5	(593.78,1504.27),(437.14,545.33)	str
GSGUIDE3	(537.68,1656.18),(360.10,1393.84)	str
GSGUIDE7	(223.31,1205.23),(687.61,1805.82)	str
GSGUIDE8	(479.93,780.28),(548.26,388.92)	str
GSGUIDE0	(167.25,277.52),(622.59,595.97)	str
ARCHIVE	/exposures/desi/20220113/00118526/guide-00118526.fits.fz	str
CHECKSUM	lFAHlC7GlCAGlC5G	str	HDU checksum updated 2022-01-14T11:13:59
DATASUM	0	str	data unit checksum updated 2022-01-14T11:13:59

Empty HDU.

HDU01

EXTNAME = PMGSTARS

Binary table of candidate guide/ETC stars detected by PlateMaker.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	86	int	width of table in bytes
NAXIS2	18	int	number of rows in table
CHECKSUM	YeEnYZBmYbBmYZBm	str	HDU checksum updated 2022-01-14T11:13:59
DATASUM	315340011	str	data unit checksum updated 2022-01-14T11:13:59

Required Data Table Columns

Name	Type	Units	Description
GFA_LOC	char[6]		PETAL_LOC number
RA	float64		Star RA in degrees
DEC	float64		Star Dec in degrees
ROW	float64		Star y pixel coord
COL	float64		Star x pixel coord
RA_IVAR	float64		RA inverse variance
DEC_IVAR	float64		Dec inverse variance
MAG	float64		Star magnitude
MORPHTYPE	int64		Morphological type
GUIDE_FLAG	int64		Guiding bitmask
ETC_FLAG [1]	int64		ETC bitmask

[1]

Optional

COL is the x pixel coordinate of each star in a convention where the left edge of the image has x = 0.

ROW is the y pixel coordinate of each star in a convention where the bottom edge of the image has y = 0.

So in this convention the center of the lower left pixel is (x, y) = (0.5, 0.5) rather than (0, 0).

The star MAG is a synthetic version of DECam r created from Gaia photometry, inherited from the fiberassign GFA_TARGETS extension.

MORPHTYPE is the GFA_TARGETS morphological type; this may, by definition, always be equal to 0, since the GFA_TARGETS target list should not include resolved galaxies.

GUIDE_FLAG is a flag indicating whether each star is suitable for use as a guide star. This may always be equal to 1 by definition, as the PMGSTARS table would simply discard any star not suitable for use as a guide star.

ETC_FLAG is a bitmask indicating whether each PlateMaker-selected guide star is suitable for use by the ETC. The main problem case that ETC_FLAG is supposed to address is variable stars, which can be fine for guiding but would mess up ETC transparency estimates. ETC_FLAG = 0 means that a star is usable for the ETC, whereas nonzero ETC_FLAG means that a star should not be used by the ETC.

HDU02

EXTNAME = GUIDE5

GUIDE5 image cube

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	8	int	width of table in bytes
NAXIS2	74304	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
DEVICE	GUIDE5	str	Device/controller name
UNIT	5	int	Unit number/letter
UNITTYPE	GUIDE	str	Image Sources/Component
EXPID	118526	int	Exposure number
FRAMES	72	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	2022-01-14T11:03:58.319124	str	[UTC] Observation data and start time
MJD-OBS	59593.46109166	float	Modified Julian Date of observation
OPENSHUT	2022-01-14T11:03:58.319124	str	Time shutter opened
ST	11:13:16.9528	str	Local Sidereal time at observation start (HH:MM
ACQTIME	15.0	float	[s] acqusition image exposure time
GUIDTIME	5.0	float	[s] guider GFA exposure time
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	2000.0	float	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	946.7,-231.6,-83.4,-18.3,9.9,138.8	str	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
WCSAXES	2	int
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
CTYPE1	RA—TAN	str
CTYPE2	DEC–TAN	str
CD1_1	5.6345e-05	float
CD1_2	-1.6764e-05	float
CD2_1	-1.8252e-05	float
CD2_2	-5.1779e-05	float
SHAPE	1032,2248	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	normal	str	GFA readout mode (loop/normal)
DEVICEID	dev08	str	GFA device id (serial number)
REQTIME	1860.0	float	[s] Requested exposure time
CHECKSUM	drbFfoZDdobDdoZD	str	HDU checksum updated 2022-01-14T11:13:59
DATASUM	1908774157	str	data unit checksum updated 2022-01-14T11:13:59

Data: FITS image [int16 (compressed), 2248x1032x72]

HDU03

EXTNAME = GUIDE5T

GUIDE5 image cube metadata

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	242	int	width of table in bytes
NAXIS2	72	int	number of rows in table
CHECKSUM	CZCLCWCKCWCKCWCK	str	HDU checksum updated 2022-01-14T11:13:59
DATASUM	79233899	str	data unit checksum updated 2022-01-14T11:13:59

Required Data Table Columns

Name	Type	Units	Description
EXPTIME	float64		Exposure time (sec)
NIGHT	int64		Observing night
DATE-OBS	char[26]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
TIME-OBS	char[15]		HH:MM:SS.SSSSSS (UT)
MJD-OBS	float64		MJD (start of frame)
OPENSHUT	char[*]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
ST	char[*]		HH:MM:SS.SS (Local Sidereal Time at frame start)
HEXPOS	char[34]		Hexapod position
GAMBNTT	float64		GFA ambient temp (C)
GFPGAT	float64		GFA FPGA temp (C)
GFILTERT	float64		GFA filter temp (C)
GCOLDTEC	float64		GFA cold peltier temp (C)
GHOTTEC	float64		GFA hot peltier temp (C)
GCCDTEMP	float64		GFA CCD temp (C)
GCAMTEMP	float64		GFA camera temp (C)
GHUMID2	float64		GFA humidity 2
GHUMID3	float64		GFA humidity 3
CRPIX1	float64		Reference pixel in axis1
CRPIX2	float64		Reference pixel in axis2
CRVAL1	float64		Physical value of the reference pixel
CRVAL2	float64		Physical value of the reference pixel

HEXPOS is a string containing the six hexapod parameters separated by commas, ordered as X, Y, Z, tip, tilt, rotation (positions in microns, angles in arcseconds).

HDU04

EXTNAME = GUIDE3

GUIDE3 image cube

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	8	int	width of table in bytes
NAXIS2	74304	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
DEVICE	GUIDE3	str	Device/controller name
UNIT	3	int	Unit number/letter
UNITTYPE	GUIDE	str	Image Sources/Component
EXPID	118526	int	Exposure number
FRAMES	72	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	2022-01-14T11:03:58.319124	str	[UTC] Observation data and start time
MJD-OBS	59593.46109166	float	Modified Julian Date of observation
OPENSHUT	2022-01-14T11:03:58.319124	str	Time shutter opened
ST	11:13:16.9528	str	Local Sidereal time at observation start (HH:MM
ACQTIME	15.0	float	[s] acqusition image exposure time
GUIDTIME	5.0	float	[s] guider GFA exposure time
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	2000.0	float	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	946.7,-231.6,-83.4,-18.3,9.9,138.8	str	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
WCSAXES	2	int
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
CTYPE1	RA—TAN	str
CTYPE2	DEC–TAN	str
CD1_1	3.4943e-05	float
CD1_2	4.3939e-05	float
CD2_1	4.7823e-05	float
CD2_2	-3.2116e-05	float
SHAPE	1032,2248	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	normal	str	GFA readout mode (loop/normal)
DEVICEID	dev02	str	GFA device id (serial number)
REQTIME	1860.0	float	[s] Requested exposure time
CHECKSUM	loGEloDBloDBloDB	str	HDU checksum updated 2022-01-14T11:14:00
DATASUM	2587335691	str	data unit checksum updated 2022-01-14T11:14:00

Data: FITS image [int16 (compressed), 2248x1032x72]

HDU05

EXTNAME = GUIDE3T

GUIDE3 image cube metadata

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	242	int	width of table in bytes
NAXIS2	72	int	number of rows in table
CHECKSUM	ZA2Ve40TZ90Tb90T	str	HDU checksum updated 2022-01-14T11:14:00
DATASUM	1996482551	str	data unit checksum updated 2022-01-14T11:14:00

Required Data Table Columns

Name	Type	Units	Description
EXPTIME	float64		Exposure time (sec)
NIGHT	int64		Observing night
DATE-OBS	char[26]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
TIME-OBS	char[15]		HH:MM:SS.SSSSSS (UT)
MJD-OBS	float64		MJD (start of frame)
OPENSHUT	char[*]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
ST	char[*]		HH:MM:SS.SS (Local Sidereal Time at frame start)
HEXPOS	char[34]		Hexapod position
GAMBNTT	float64		GFA ambient temp (C)
GFPGAT	float64		GFA FPGA temp (C)
GFILTERT	float64		GFA filter temp (C)
GCOLDTEC	float64		GFA cold peltier temp (C)
GHOTTEC	float64		GFA hot peltier temp (C)
GCCDTEMP	float64		GFA CCD temp (C)
GCAMTEMP	float64		GFA camera temp (C)
GHUMID2	float64		GFA humidity 2
GHUMID3	float64		GFA humidity 3
CRPIX1	float64		Reference pixel in axis1
CRPIX2	float64		Reference pixel in axis2
CRVAL1	float64		Physical value of the reference pixel
CRVAL2	float64		Physical value of the reference pixel

HDU06

EXTNAME = GUIDE2

GUIDE2 image cube

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	8	int	width of table in bytes
NAXIS2	74304	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
DEVICE	GUIDE2	str	Device/controller name
UNIT	2	int	Unit number/letter
UNITTYPE	GUIDE	str	Image Sources/Component
EXPID	118526	int	Exposure number
FRAMES	72	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	2022-01-14T11:03:58.319124	str	[UTC] Observation data and start time
MJD-OBS	59593.46109166	float	Modified Julian Date of observation
OPENSHUT	2022-01-14T11:03:58.319124	str	Time shutter opened
ST	11:13:16.9528	str	Local Sidereal time at observation start (HH:MM
ACQTIME	15.0	float	[s] acqusition image exposure time
GUIDTIME	5.0	float	[s] guider GFA exposure time
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	2000.0	float	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	946.7,-231.6,-83.4,-18.3,9.9,138.8	str	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
WCSAXES	2	int
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
CTYPE1	RA—TAN	str
CTYPE2	DEC–TAN	str
CD1_1	1.9486e-07	float
CD1_2	5.4424e-05	float
CD2_1	5.9241e-05	float
CD2_2	-1.8383e-07	float
SHAPE	1032,2248	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	normal	str	GFA readout mode (loop/normal)
DEVICEID	dev06	str	GFA device id (serial number)
REQTIME	1860.0	float	[s] Requested exposure time
CHECKSUM	9iG4AfE49fE4AfE4	str	HDU checksum updated 2022-01-14T11:14:01
DATASUM	2955333335	str	data unit checksum updated 2022-01-14T11:14:01

Data: FITS image [int16 (compressed), 2248x1032x72]

HDU07

EXTNAME = GUIDE2T

GUIDE2 image cube metadata

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	242	int	width of table in bytes
NAXIS2	72	int	number of rows in table
CHECKSUM	7qDGAoD90oDE7oD9	str	HDU checksum updated 2022-01-14T11:14:01
DATASUM	2746564241	str	data unit checksum updated 2022-01-14T11:14:01

Required Data Table Columns

Name	Type	Units	Description
EXPTIME	float64		Exposure time (sec)
NIGHT	int64		Observing night
DATE-OBS	char[26]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
TIME-OBS	char[15]		HH:MM:SS.SSSSSS (UT)
MJD-OBS	float64		MJD (start of frame)
OPENSHUT	char[*]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
ST	char[*]		HH:MM:SS.SS (Local Sidereal Time at frame start)
HEXPOS	char[34]		Hexapod position
GAMBNTT	float64		GFA ambient temp (C)
GFPGAT	float64		GFA FPGA temp (C)
GFILTERT	float64		GFA filter temp (C)
GCOLDTEC	float64		GFA cold peltier temp (C)
GHOTTEC	float64		GFA hot peltier temp (C)
GCCDTEMP	float64		GFA CCD temp (C)
GCAMTEMP	float64		GFA camera temp (C)
GHUMID2	float64		GFA humidity 2
GHUMID3	float64		GFA humidity 3
CRPIX1	float64		Reference pixel in axis1
CRPIX2	float64		Reference pixel in axis2
CRVAL1	float64		Physical value of the reference pixel
CRVAL2	float64		Physical value of the reference pixel

HDU08

EXTNAME = GUIDE7

GUIDE7 image cube

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	8	int	width of table in bytes
NAXIS2	74304	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
DEVICE	GUIDE7	str	Device/controller name
UNIT	7	int	Unit number/letter
UNITTYPE	GUIDE	str	Image Sources/Component
EXPID	118526	int	Exposure number
FRAMES	72	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	2022-01-14T11:03:58.319124	str	[UTC] Observation data and start time
MJD-OBS	59593.46109166	float	Modified Julian Date of observation
OPENSHUT	2022-01-14T11:03:58.319124	str	Time shutter opened
ST	11:13:16.9528	str	Local Sidereal time at observation start (HH:MM
ACQTIME	15.0	float	[s] acqusition image exposure time
GUIDTIME	5.0	float	[s] guider GFA exposure time
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	2000.0	float	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	946.7,-231.6,-83.4,-18.3,9.9,138.8	str	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
WCSAXES	2	int
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
CTYPE1	RA—TAN	str
CTYPE2	DEC–TAN	str
CD1_1	2.0968e-07	float
CD1_2	-5.443e-05	float
CD2_1	-5.9249e-05	float
CD2_2	-1.8791e-07	float
SHAPE	1032,2248	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	normal	str	GFA readout mode (loop/normal)
DEVICEID	dev01	str	GFA device id (serial number)
REQTIME	1860.0	float	[s] Requested exposure time
CHECKSUM	HB4WH93VHA3VH73V	str	HDU checksum updated 2022-01-14T11:14:02
DATASUM	1347049373	str	data unit checksum updated 2022-01-14T11:14:02

Data: FITS image [int16 (compressed), 2248x1032x72]

HDU09

EXTNAME = GUIDE7T

GUIDE7 image cube metadata

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	242	int	width of table in bytes
NAXIS2	72	int	number of rows in table
CHECKSUM	IbGoJaDnIaDnIaDn	str	HDU checksum updated 2022-01-14T11:14:02
DATASUM	3635643212	str	data unit checksum updated 2022-01-14T11:14:02

Required Data Table Columns

Name	Type	Units	Description
EXPTIME	float64		Exposure time (sec)
NIGHT	int64		Observing night
DATE-OBS	char[26]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
TIME-OBS	char[15]		HH:MM:SS.SSSSSS (UT)
MJD-OBS	float64		MJD (start of frame)
OPENSHUT	char[*]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
ST	char[*]		HH:MM:SS.SS (Local Sidereal Time at frame start)
HEXPOS	char[34]		Hexapod position
GAMBNTT	float64		GFA ambient temp (C)
GFPGAT	float64		GFA FPGA temp (C)
GFILTERT	float64		GFA filter temp (C)
GCOLDTEC	float64		GFA cold peltier temp (C)
GHOTTEC	float64		GFA hot peltier temp (C)
GCCDTEMP	float64		GFA CCD temp (C)
GCAMTEMP	float64		GFA camera temp (C)
GHUMID2	float64		GFA humidity 2
GHUMID3	float64		GFA humidity 3
CRPIX1	float64		Reference pixel in axis1
CRPIX2	float64		Reference pixel in axis2
CRVAL1	float64		Physical value of the reference pixel
CRVAL2	float64		Physical value of the reference pixel

HDU10

EXTNAME = GUIDE8

GUIDE8 image cube

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	8	int	width of table in bytes
NAXIS2	74304	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
DEVICE	GUIDE8	str	Device/controller name
UNIT	8	int	Unit number/letter
UNITTYPE	GUIDE	str	Image Sources/Component
EXPID	118526	int	Exposure number
FRAMES	72	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	2022-01-14T11:03:58.319124	str	[UTC] Observation data and start time
MJD-OBS	59593.46109166	float	Modified Julian Date of observation
OPENSHUT	2022-01-14T11:03:58.319124	str	Time shutter opened
ST	11:13:16.9528	str	Local Sidereal time at observation start (HH:MM
ACQTIME	15.0	float	[s] acqusition image exposure time
GUIDTIME	5.0	float	[s] guider GFA exposure time
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	2000.0	float	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	946.7,-231.6,-83.4,-18.3,9.9,138.8	str	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
WCSAXES	2	int
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
CTYPE1	RA—TAN	str
CTYPE2	DEC–TAN	str
CD1_1	-3.4681e-05	float
CD1_2	-4.4134e-05	float
CD2_1	-4.804e-05	float
CD2_2	3.1872e-05	float
SHAPE	1032,2248	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	normal	str	GFA readout mode (loop/normal)
DEVICEID	dev04	str	GFA device id (serial number)
REQTIME	1860.0	float	[s] Requested exposure time
CHECKSUM	9KhoAJhn4Jhn9Jhn	str	HDU checksum updated 2022-01-14T11:14:03
DATASUM	663748813	str	data unit checksum updated 2022-01-14T11:14:03

Data: FITS image [int16 (compressed), 2248x1032x72]

HDU11

EXTNAME = GUIDE8T

GUIDE8 image cube metadata

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	241	int	width of table in bytes
NAXIS2	72	int	number of rows in table
CHECKSUM	EAADG439E99CE999	str	HDU checksum updated 2022-01-14T11:14:03
DATASUM	2061256282	str	data unit checksum updated 2022-01-14T11:14:03

Required Data Table Columns

Name	Type	Units	Description
EXPTIME	float64		Exposure time (sec)
NIGHT	int64		Observing night
DATE-OBS	char[26]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
TIME-OBS	char[15]		HH:MM:SS.SSSSSS (UT)
MJD-OBS	float64		MJD (start of frame)
OPENSHUT	char[*]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
ST	char[*]		HH:MM:SS.SS (Local Sidereal Time at frame start)
HEXPOS	char[34]		Hexapod position
GAMBNTT	float64		GFA ambient temp (C)
GFPGAT	float64		GFA FPGA temp (C)
GFILTERT	float64		GFA filter temp (C)
GCOLDTEC	float64		GFA cold peltier temp (C)
GHOTTEC	float64		GFA hot peltier temp (C)
GCCDTEMP	float64		GFA CCD temp (C)
GCAMTEMP	float64		GFA camera temp (C)
GHUMID2	float64		GFA humidity 2
GHUMID3	float64		GFA humidity 3
CRPIX1	float64		Reference pixel in axis1
CRPIX2	float64		Reference pixel in axis2
CRVAL1	float64		Physical value of the reference pixel
CRVAL2	float64		Physical value of the reference pixel

HDU12

EXTNAME = GUIDE0

GUIDE0 image cube

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	8	int	width of table in bytes
NAXIS2	74304	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
DEVICE	GUIDE0	str	Device/controller name
UNIT	0	int	Unit number/letter
UNITTYPE	GUIDE	str	Image Sources/Component
EXPID	118526	int	Exposure number
FRAMES	72	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	2022-01-14T11:03:58.319124	str	[UTC] Observation data and start time
MJD-OBS	59593.46109166	float	Modified Julian Date of observation
OPENSHUT	2022-01-14T11:03:58.319124	str	Time shutter opened
ST	11:13:16.9528	str	Local Sidereal time at observation start (HH:MM
ACQTIME	15.0	float	[s] acqusition image exposure time
GUIDTIME	5.0	float	[s] guider GFA exposure time
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	2000.0	float	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	946.7,-231.6,-83.4,-18.3,9.9,138.8	str	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
WCSAXES	2	int
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
CTYPE1	RA—TAN	str
CTYPE2	DEC–TAN	str
CD1_1	-5.6334e-05	float
CD1_2	1.6861e-05	float
CD2_1	1.836e-05	float
CD2_2	5.1764e-05	float
SHAPE	1032,2248	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	normal	str	GFA readout mode (loop/normal)
DEVICEID	dev10	str	GFA device id (serial number)
REQTIME	1860.0	float	[s] Requested exposure time
CHECKSUM	X2EZY2DZX2DZX2DZ	str	HDU checksum updated 2022-01-14T11:14:04
DATASUM	2619950170	str	data unit checksum updated 2022-01-14T11:14:04

Data: FITS image [int16 (compressed), 2248x1032x72]

HDU13

EXTNAME = GUIDE0T

GUIDE0 image cube metadata

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	242	int	width of table in bytes
NAXIS2	72	int	number of rows in table
CHECKSUM	Jo9AJm64Jm6AJm63	str	HDU checksum updated 2022-01-14T11:14:04
DATASUM	2766359628	str	data unit checksum updated 2022-01-14T11:14:04

Required Data Table Columns

Name	Type	Units	Description
EXPTIME	float64		Exposure time (sec)
NIGHT	int64		Observing night
DATE-OBS	char[26]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
TIME-OBS	char[15]		HH:MM:SS.SSSSSS (UT)
MJD-OBS	float64		MJD (start of frame)
OPENSHUT	char[*]		YYYY-MM-DDTHH:MM:SS.SSSSSS (UT)
ST	char[*]		HH:MM:SS.SS (Local Sidereal Time at frame start)
HEXPOS	char[34]		Hexapod position
GAMBNTT	float64		GFA ambient temp (C)
GFPGAT	float64		GFA FPGA temp (C)
GFILTERT	float64		GFA filter temp (C)
GCOLDTEC	float64		GFA cold peltier temp (C)
GHOTTEC	float64		GFA hot peltier temp (C)
GCCDTEMP	float64		GFA CCD temp (C)
GCAMTEMP	float64		GFA camera temp (C)
GHUMID2	float64		GFA humidity 2
GHUMID3	float64		GFA humidity 3
CRPIX1	float64		Reference pixel in axis1
CRPIX2	float64		Reference pixel in axis2
CRVAL1	float64		Physical value of the reference pixel
CRVAL2	float64		Physical value of the reference pixel