fiberflatnight-CAMERA-NIGHT.fits

Summary:

Relative fiber-to-fiber variations (“fiberflat”) as measured by continuum lamp calibration spectra, combined across multiple exposures. Corrected flux = original flux / fiberflat.

Naming Convention:

fiberflatnight-CAMERA-NIGHT.fits, where CAMERA is e.g., “b0”, “r5”, etc. and NIGHT is the observation night in YYYYMMDD format.

Regex:

fiberflatnight-[brz][0-9]-[0-9]{8}\.fits

File Type:

FITS, 10 MB

Contents

Number	EXTNAME	Type	Contents
HDU0	FIBERFLAT	IMAGE	Relative fiber-to-fiber variation
HDU1	IVAR	IMAGE	Inverse variance of fiberflat
HDU2	MASK	IMAGE	Mask of fiberflat (0=good)
HDU3	MEANSPEC	IMAGE	Average spectrum
HDU4	WAVELENGTH	IMAGE	Wavelength
HDU5	FIBERMAP	BINTABLE	fibermap

FITS Header Units

HDU0

EXTNAME = FIBERFLAT

Fiber flat field correction to homogeneize the response among fibers of the same camera, for each wavelength. 2D array of dimension [nspec, nwave]. nspec is the number of fibers per camera. nwave in the length of the wavelength array. The fiber flat field of all fibers share the same wavelength grid (given in HDU WAVELENGTH). This file is the fiber flat derived from a series of flat field exposures. It is the one used for the science observations during the night.

Required Header Keywords

Required Header Keywords table

KEY	Example Value	Type	Comment
NAXIS1	2751	int
NAXIS2	500	int
EXPID	91342	int	Exposure number
EXPFRAME	0	int	Frame number
FLAVOR	science	str	Observation type
SEQUENCE	Spectrographs	str	OCS Sequence name
PURPOSE	Main Survey	str	Purpose of observing night
PROGRAM	CALIB DESI-CALIB-00 LEDs only	str	Program name
PROPID	2020B-5000	str	Proposal ID
OBSERVER	DESIObserver	str	Names of observers
LEAD	RunManager	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	20210606	int	Observing night
TIMESYS	UTC	str	Time system used for date-obs
DATE-OBS	2021-06-07T00:37:22.927269888	str	[UTC] Observation data and start tim
TIME-OBS	2021-06-06T00:37:22.927269888	str	[UTC] Observation start time
MJD-OBS	59372.02595981	float	Modified Julian Date of observation
OPENSHUT	2021-06-07T00:37:23.710751	Unknown	Time shutter opened
ST	10:13:31.760000	str	Local Sidereal time at observation start (HH:MM
EXPTIME	120.04	float	[s] Actual exposure time
DELTARA	0.0	float	[arcsec] Offset], right ascension, observer inp
DELTADEC	0.0	float	[arcsec] Offset], declination, observer input
VCCD	ON	str	True (ON) if CCD voltage is on
VCCDON	2021-05-19T22:18:47.035384	str	Time when CCD voltage was turned on
VCCDSEC	1563696.6	float	[s] CCD on time in seconds
EQUINOX	2000.0	float	Epoch of observation
SPECGRPH	0	int	Spectrograph logical name (SP)
SPECID	4	int	Spectrograph serial number (SM)
FEEBOX	lbnl081	str	CCD Controller serial number
VESSEL	15	int	Cryostat serial number
FEEVER	v20160312	str	CCD Controller version
DETFLVER [1]	FAILED: invalid argument for get command	str	CCD Controller detector f
FEEPOWER	ON	str	FEE power status
FEEDMASK	2134851391	int	FEE dac mask
FEECMASK	1048575	int	FEE clk mask
CCDTEMP	850.0	float	[deg C] CCD controller CCD temperature
RADESYS	FK5	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	/data/msdos/dos_home/architectures/kpno/desi.ini	str	DOS Configuration
CLOCK0	3.9999,-4.0002	str	[V] high rail, low rail
CCDSECD	[2049:4096, 2049:4096]	str	CCD section for quadrant D
CLOCK17	3.9999,-4.0002	str	[V] high rail, low rail
DELAYS	13, 13, 25, 25, 8, 3000, 7, 7, 400, 7	str	[10] Delay settings
BIASSECD	[2117:2180, 2114:4161]	str	Bias section for quadrant D
DATASECD	[2181:4228, 2114:4161]	str	Data section for quadrant D
CLOCK14	3.0,-7.0002	str	[V] high rail, low rail
PRRSECC	[5:2052, 4162:4162]	str	Row prescan section for quadrant C
CCDSECC	[1:2048, 2049:4096]	str	CCD section for quadrant C
CPUTEMP	56.0097	float	[deg C] CCD controller CPU temperature
BIASSECA	[2053:2116, 2:2049]	str	Bias section for quadrant A
DAC13	-5.0006,-4.9816	str	[V] set value, measured value
OFFSET5	-1.100000023841858,0.0105	str	[V] set value, measured value
DAC0	15.9998,15.965	str	[V] set value, measured value
DAC11	26.9998,26.9049	str	[V] set value, measured value
OFFSET6	-1.100000023841858,0.0158	str	[V] set value, measured value
OFFSET2	-1.5,15.8311	str	[V] set value, measured value
CLOCK15	0.0,0.0	str	[V] high rail, low rail
TRIMSECB	[2181:4228, 2:2049]	str	Trim section for quadrant B
ORSECC	[5:2052, 2082:2113]	str	Row overscan section for quadrant C
BIASSECB	[2117:2180, 2:2049]	str	Bias section for quadrant B
OFFSET1	-1.5,15.8208	str	[V] set value, measured value
ORSECA	[5:2052, 2050:2081]	str	Row overscan section for quadrant A
CAMERA	b0	str	Camera name
CLOCK1	3.9999,-4.0002	str	[V] high rail, low rail
DETSECC	[1:2048, 2049:4096]	str	Detector section for quadrant C
DAC5	0.0,0.0158	str	[V] set value, measured value
TRIMSECC	[5:2052, 2114:4161]	str	Trim section for quadrant C
DAC7	0.0,0.0105	str	[V] set value, measured value
DAC3	15.9998,15.965	str	[V] set value, measured value
ORSECD	[2181:4228, 2082:2113]	str	Row bias section for quadrant D
CCDSECB	[2049:4096, 1:2048]	str	CCD section for quadrant B
DAC1	15.9998,15.8208	str	[V] set value, measured value
DAC8	26.9998,26.6081	str	[V] set value, measured value
CCDSIZE	4162,4232	str	CCD size in pixels (rows, columns)
CASETEMP	56.3689	float	[deg C] CCD controller case temperature
PRESECA	[1:4, 2:2049]	str	Prescan section for quadrant A
CLOCK3	6.9999,-2.0001	str	[V] high rail, low rail
SETTINGS	detectors_sm_20210128.json	str	Name of DESI CCD settings file
OFFSET3	-1.5,15.965	str	[V] set value, measured value
OFFSET0	-1.5,15.965	str	[V] set value, measured value
DETSECD	[2049:4096, 2049:4096]	str	Detector section for quadrant D
AMPSECB	[2049:4096, 2048:1]	str	AMP section for quadrant B
DATASECA	[5:2052, 2:2049]	str	Data section for quadrant A
CLOCK2	3.9999,-4.0002	str	[V] high rail, low rail
BLDTIME	0.3504	float	[s] Time to build image
CCDNAME	CCDSM4B	str	CCD name
PRRSECA	[5:2052, 1:1]	str	Row prescan section for quadrant A
DAC14	0.0,0.8216	str	[V] set value, measured value
CCDCFG	default_sta_20210128.cfg	str	CCD configuration file
PRESECB	[4229:4232, 2:2049]	str	Prescan section for quadrant B
CDSPARMS	400, 400, 8, 1000	str	CDS parameters
CRYOTEMP [1]	162.97	float	[deg K] Cryostat CCD temperature
CLOCK6	3.9999,-4.0002	str	[V] high rail, low rail
DATASECB	[2181:4228, 2:2049]	str	Data section for quadrant B
CLOCK11	0.0,0.0	str	[V] high rail, low rail
DAC9	26.9998,26.9346	str	[V] set value, measured value
DAC2	15.9998,15.8208	str	[V] set value, measured value
DAC6	0.0,0.0158	str	[V] set value, measured value
DETSECA	[1:2048, 1:2048]	str	Detector section for quadrant A
CLOCK13	3.0,-7.0002	str	[V] high rail, low rail
DATASECC	[5:2052, 2114:4161]	str	Data section for quadrant C
CLOCK16	0.0,0.0	str	[V] high rail, low rail
CLOCK9	3.0,-7.0002	str	[V] high rail, low rail
TRIMSECA	[5:2052, 2:2049]	str	Trim section for quadrant A
DAC15	19.9997,20.0616	str	[V] set value, measured value
AMPSECD	[4096:2049, 4096:2049]	str	AMP section for quadrant D
DAC17	-0.0,0.0366	str	[V] set value, measured value
DETSECB	[2049:4096, 1:2048]	str	Detector section for quadrant B
PRRSECD	[2181:4228, 4162:4162]	str	Row prescan section for quadrant D
PRRSECB	[2181:4228, 1:1]	str	Row prescan section for quadrant B
CLOCK8	3.0,-7.0002	str	[V] high rail, low rail
OFFSET4	-1.100000023841858,0.0053	str	[V] set value, measured value
AMPSECC	[2048:1, 2049:4096]	str	AMP section for quadrant C
CCDTMING	flatdark_sta_timing.txt	str	CCD timing file
TRIMSECD	[2181:4228, 2114:4161]	str	Trim section for quadrant D
CCDPREP	purge,clear	str	CCD prep actions
CLOCK18	3.9999,-4.0002	str	[V] high rail, low rail
PRESECD	[4229:4232, 2114:4161]	str	Prescan section for quadrant D
DAC4	0.0,0.0105	str	[V] set value, measured value
DAC16	0.0,65.6502	str	[V] set value, measured value
BIASSECC	[2053:2116, 2114:4161]	str	Bias section for quadrant C
ORSECB	[2181:4228, 2050:2081]	str	Row overscan section for quadrant B
CLOCK10	3.0,-7.0002	str	[V] high rail, low rail
DETECTOR	sn22797	str	Detector (ccd) identification
CLOCK7	6.9999,-2.0001	str	[V] high rail, low rail
DAC10	26.9998,26.8456	str	[V] set value, measured value
CLOCK5	3.9999,-4.0002	str	[V] high rail, low rail
AMPSECA	[1:2048, 1:2048]	str	AMP section for quadrant A
CLOCK12	3.0,-7.0002	str	[V] high rail, low rail
PRESECC	[1:4, 2114:4161]	str	Prescan section for quadrant C
CRYOPRES [1]	1.002e-07	str	[mb] Cryostat pressure (IP)
DAC12	4.9997,22.62	str	[V] set value, measured value
OFFSET7	-1.100000023841858,0.0105	str	[V] set value, measured value
CLOCK4	3.9999,-4.0002	str	[V] high rail, low rail
DIGITIME	54.7987	float	[s] Time to digitize image
PGAGAIN	5	int	Controller gain
CCDSECA	[1:2048, 1:2048]	str	CCD section for quadrant A
REQTIME	120.0	float	[s] Requested exposure time
OBSID	kp4m20210607t003722	str	Unique observation identifier
PROCTYPE	RAW	str	Data processing level
PRODTYPE	image	str	Data product type
CHECKSUM	9aCgFaCZ9aCdCaCZ	str	HDU checksum updated 2022-02-06T08:13:11
DATASUM	4268167737	str	data unit checksum updated 2022-02-06T08:13:11
GAINA	1.133	float	e/ADU (gain applied to image)
SATULEVA	65535.0	float	saturation or non lin. level, in ADU, inc. bias
OSTEPA	1.2530904947198	float	ADUs (max-min of median overscan per row)
OMETHA	AVERAGE	str	use average overscan
OVERSCNA	1209.671055084825	float	ADUs (gain not applied)
OBSRDNA	4.085456675058811	float	electrons (gain is applied)
SATUELEA	72880.5976945889	float	saturation or non lin. level, in electrons
GAINB	1.117	float	e/ADU (gain applied to image)
SATULEVB	65535.0	float	saturation or non lin. level, in ADU, inc. bias
OSTEPB	1.01353762880899	float	ADUs (max-min of median overscan per row)
OMETHB	AVERAGE	str	use average overscan
OVERSCNB	1198.692841450332	float	ADUs (gain not applied)
OBSRDNB	2.953525302217383	float	electrons (gain is applied)
SATUELEB	71863.65509609997	float	saturation or non lin. level, in electrons
GAINC	1.122	float	e/ADU (gain applied to image)
SATULEVC	65535.0	float	saturation or non lin. level, in ADU, inc. bias
OSTEPC	1.285695178230526	float	ADUs (max-min of median overscan per row)
OMETHC	AVERAGE	str	use average overscan
OVERSCNC	1190.789779784249	float	ADUs (gain not applied)
OBSRDNC	3.539433190358737	float	electrons (gain is applied)
SATUELEC	72194.20386708208	float	saturation or non lin. level, in electrons
GAIND	1.122	float	e/ADU (gain applied to image)
SATULEVD	65535.0	float	saturation or non lin. level, in ADU, inc. bias
OSTEPD	0.9090212500377675	float	ADUs (max-min of median overscan per row)
OMETHD	AVERAGE	str	use average overscan
OVERSCND	1181.653571158484	float	ADUs (gain not applied)
OBSRDND	3.286804241230265	float	electrons (gain is applied)
SATUELED	72204.4546931602	float	saturation or non lin. level, in electrons
FIBERMIN	0	int
LONGSTRN	OGIP 1.0	str	The OGIP Long String Convention may be used.
MODULE	CI	str	Image Sources/Component
FRAMES	None	Unknown	Number of Frames in Archive
COSMSPLT	F	bool	Cosmics split exposure if true
MAXSPLIT	0	int	Number of allowed exposure splits
OBSTYPE	FLAT	str	Spectrograph observation type
MANIFEST	F	bool	DOS exposure manifest
OBJECT		str	Object name
NTSSURVY [1]	na	str	NTS survey name
SEQID	3 requests	str	Exposure sequence identifier
SEQNUM	1	int	Number of exposure in sequence
SEQTOT	3	int	Total number of exposures in sequence
SEQSTART [1]	2021-06-07T00:37:19.875612	str	Start time of sequence processing
CAMSHUT	open	str	Shutter status during observation
WHITESPT [1]	T	bool	Telescope is at whitespot
ZENITH [1]	F	bool	Telescope is at zenith
SEANNEX [1]	F	bool	Telescope is at SE annex
BEYONDP [1]	F	bool	Telescope is beyond pole
FIDUCIAL [1]	off	str	Fiducials status during observation
AIRMASS [1]	1.521278	float	Airmass
FOCUS [1]	1143.6,-727.1,-829.6,5.1,35.1,-0.0	str	Telescope focus settings
PMREADY [1]	T	bool	Primary mirror ready
DOMEAZ [1]	106.784	float	[deg] Dome azimuth angle
DOMINPOS [1]	T	bool	Dome is in position
GUIDOFFR [1]	0.0	float	[arcsec] Cummulative guider offset (RA)
GUIDOFFD [1]	-0.0	float	[arcsec] Cummulative guider offset (dec)
SUNRA [1]	75.340488	float	[deg] Sun RA at start of exposure
SUNDEC [1]	22.752292	float	[deg] Sun declination at start of exposure
MOONDEC [1]	11.86839	float	[deg] Moon declination at start of exposure
MOONRA [1]	37.518292	float	[deg] Moon RA at start of exposure
MOONSEP [1]	56.776	float	[deg] Moon Separation
MOUNTAZ [1]	286.506397	float	[deg] Mount azimuth angle
MOUNTDEC [1]	31.963302	float	[deg] Mount declination
MOUNTEL [1]	41.036698	float	[deg] Mount elevation angle
MOUNTHA [1]	58.478595	float	[deg] Mount hour angle
INCTRL [1]	F	bool	DESI in control
INPOS [1]	T	bool	Mount in position
MNTOFFD [1]	-0.0	float	[arcsec] Mount offset (dec)
MNTOFFR [1]	-0.0	float	[arcsec] Mount offset (RA)
PARALLAC [1]	73.493607	float	[deg] Parallactic angle
SKYDEC [1]	31.963302	float	[deg] Telescope declination (pointing on sky)
SKYRA [1]	94.904717	float	[deg] Telescope right ascension (pointing on sk
TARGTDEC [1]	31.963305	float	[deg] Target declination (to TCS)
TARGTRA [1]	88.232751	float	[deg] Target right ascension (to TCS)
TARGTAZ [1]	288.686999	float	[deg] Target azimuth
TARGTEL [1]	35.641227	float	[deg] Target elevation
TRGTOFFD [1]	0.0	float	[arcsec] Telescope target offset (dec)
TRGTOFFR [1]	0.0	float	[arcsec] Telescope target offset (RA)
ZD [1]	48.963302	float	[deg] Telescope zenith distance
TCSST [1]	10:13:31.995	str	Local Sidereal time reported by TCS (HH:MM:SS)
TCSMJD [1]	59372.026394	float	MJD reported by TCS
SEEING [1]	None	Unknown	[arcsec] ETC/PM seeing
TRANSPAR [1]	None	Unknown	ETC/PM transparency
PMSEEING [1]	None	Unknown	[arcsec] PlateMaker GFAPROC seeing
PMTRANSP [1]	None	Unknown	[%] PlateMaker GFAPROC transparency
ADCCORR	F	bool	Correct pointing for ADC setting if True
ADC1PHI [1]	123.200072	float	[deg] ADC 1 angle
ADC2PHI [1]	151.330141	float	[deg] ADC 2 angle
ADC1HOME [1]	F	bool	ADC 1 at home position if True
ADC2HOME [1]	F	bool	ADC 2 at home position if True
ADC1NREV [1]	0.0	float	ADC 1 number of revs
ADC2NREV [1]	-1.0	float	ADC 2 number of revs
ADC1STAT [1]	STOPPED	str	ADC 1 status
ADC2STAT [1]	STOPPED	str	ADC 2 status
HEXPOS [1]	1143.6,-727.1,-829.6,5.1,35.1,-0.0	str	Hexapod position
HEXTRIM [1]	0.0,0.0,0.0,0.0,0.0,0.0	str	Hexapod trim values
ROTOFFST [1]	0.0	float	[arcsec] Rotator offset
ROTENBLD [1]	F	bool	Rotator enabled
ROTRATE [1]	0.0	float	[arcsec/min] Rotator rate
RESETROT	F	bool	DOS Control: reset hex rotator
GUIDMODE	catalog	str	Guider mode
SPCGRPHS	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str	Participating spectrograph
ILLSPECS [1]	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str	Participating illuminate s
CCDSPECS [1]	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str	Participating ccd spectrog
UPSSTAT [1]	SUCCESS	str	UPS Status
FILENAME	/exposures/desi/20210606/00091342/desi-00091342.fits.fz	str	Name of (F
EXCLUDED		str	Components excluded from this exposure
TCSKRA [1]	1.5 0 0	str	TCS Kalman (RA)
TCSKDEC [1]	1.5 0 0	str	TCS Kalman (dec)
TCSGRA [1]	0.3	float	TCS simple gain (RA)
TCSGDEC [1]	0.3	float	TCS simple gain (dec)
TCSMFRA [1]	1	int	TCS moving filter length (RA)
TCSMFDEC [1]	1	int	TCS moving filter length (dec)
TCSPIRA [1]	1.0,0.0,0.0,0.0	str	TCS PI settings (P, I (gain, error window, satu
TCSPIDEC [1]	1.0,0.0,0.0,0.0	str	TCS PI settings (P, I (gain, error window, satu
NSPEC	500	int	Number of spectra
WAVEMIN	3600.0	float	First wavelength [Angstroms]
WAVEMAX	5800.0	float	Last wavelength [Angstroms]
WAVESTEP	0.8	float	Wavelength step size [Angstroms]
SPECTER	0.10.0	str	https://github.com/desihub/specter
IN_PSF	SPECPROD/exposures/20210606/00091342/psf-b0-00091342.fits	str	Input sp
IN_IMG	SPECPROD/preproc/20210606/00091342/preproc-b0-00091342.fits	str
ORIG_PSF	SPECPROD/calibnight/20210606/psfnight-b0-20210606.fits	str
CHI2PDF	1.102403823484989	float
BUNIT		str	adimensional quantity to divide to flatfield a frame
USEAOS [1]	F	bool	DOS Control: AOS data available if true
SPLITIDS [1]	80644	str	List of expids for split exposures
SHACKC [1]	13.9	float	[deg C] temperature at shack ceiling
TTRUSTTT [1]	9.2	float	[deg] Telescope truss STT temperature
UTILWALL [1]	9.0	float	[deg C] temperature at utility room wall
DOMERLOW [1]	9.1	float	[deg C] temperature at dome right, lower
TPMNIBT [1]	4.6	float	[deg] Telescope mirror NIB temperature
TPMEITT [1]	4.7	float	[deg] Telescope mirror EIT temperature
PLATFORM [1]	12.4	float	[deg C] temperature at platform
THINGEW [1]	9.0	float	[deg] Telescope hinge W temperature
HUMIDITY [1]	32.0	float	[%] (outside) humidity
DOMSHUTU [1]	not open	str	Upper dome shutter
FLOOR [1]	11.1	float	[deg C] temperature at floor (LCR)
DOMELLOW [1]	9.3	float	[deg C] temperature at dome left, lower
TCSOTEMP [1]	7.1	float	[deg] Telescope center section out temperature
OUTTEMP [1]	0.0	float	[deg C] outside temperature
TGLYCOLO [1]	-0.8	float	[deg] Telescope glycol out temperature
TTRUNTTT [1]	8.8	float	[deg] Telescope truss NTT temperature
PMCOOL [1]	on	str	Primary mirror cooling
TTRUSTBT [1]	8.3	float	[deg] Telescope truss STB temperature
CFLOOR [1]	5.8	float	[deg C] temperature on C floor
TCITTEMP [1]	0.0	float	[deg] Telescope chimney IT temperature
TSERVO [1]	4.4	float	Telescope servo setpoint
WINDDIR [1]	298.0	float	[deg] wind direction
TTRWTEMP [1]	9.9	float	[deg] Telescope top ring W temperature
TPMRTDT [1]	4.52	float	[deg] Telescope mirror RTD temperature
DOMLIGHL [1]	off	str	Low dome lights
AMBIENTS [1]	13.1	float	[deg C] ambient temperature south
TPMSTAT [1]	soft air	str	Telescope mirror status
TPMSITT [1]	4.5	float	[deg] Telescope mirror SIT temperature
SHACKW [1]	11.6	float	[deg C] temperature at shack wall
TTRUWTBT [1]	8.0	float	[deg] Telescope truss WTB temperature
NWALLIN [1]	12.1	float	[deg C] temperature at north wall inside
DOMERUP [1]	10.3	float	[deg C] temperature at dome right, upper
TPMWOTT [1]	5.4	float	[deg] Telescope mirror WOT temperature
DOMEBUP [1]	14.6	float	[deg C] temperature at dome back, upper
TPMDESIT [1]	4.4	float	[deg] Telescope mirror desired temperature
TPCOTEMP [1]	4.7	float	[deg] Telescope primary cell out temperature
TTRUTSTT [1]	9.8	float	[deg] Telescope truss TST temperature
TPMWIBT [1]	4.5	float	[deg] Telescope mirror WIB temperature
TPMEOBT [1]	4.5	float	[deg] Telescope mirror EOB temperature
OUTWATTS [1]	4600.0,6900.0,4200.0	str	[W] UPS Phase A, B, C output watts
COMPDEW [1]	-7.2	float	[deg C] Computer room dewpoint
ROOF [1]	7.3	float	[deg C] temperature on roof
AMNIENTN [1]	11.6	float	[deg C] ambient temperature north
TAIRTEMP [1]	8.712	float	[deg] Telescope air temperature
COMPAMB [1]	17.2	float	[deg C] Computer room ambient temperature
TPR1HUM [1]	0.0	float	Telescope probe 1 humidity
TRUSTEMP [1]	10.133	float	[deg] Average Telescope truss temperature (only
WINDSPD [1]	6.0	float	[m/s] wind speed
PMCOVER [1]	open	str	Primary mirror cover
TDEWPNT [1]	-8.51	float	Telescope air dew point
TELBASE [1]	6.2	float	[deg C] temperature at telescope base
TPMWITT [1]	4.7	float	[deg] Telescope mirror WIT temperature
COMPHUM [1]	13.3	float	[%] Computer room humidity
TTRUTSMT [1]	10.4	float	[deg] Telescope truss TSM temperature
NWALLOUT [1]	6.3	float	[deg C] temperature at north wall outside
TAIRITMP [1]	7.9	float	[deg] Telescope air in temperature
TPMNOBT [1]	4.8	float	[deg] Telescope mirror NOB temperature
TPCITEMP [1]	4.7	float	[deg] Telescope primary cell in temperature
TTRUNTBT [1]	8.1	float	[deg] Telescope truss NTB temperature
TFLOWIN [1]	9.8	float	Telescope flow rate in
EWALLCMP [1]	7.8	float	[deg C] temperature at east wall, computer room
TDBTEMP [1]	5.1	float	[deg] Telescope dec bore temperature
TCASITMP [1]	0.0	float	[deg] Telescope Cass Cage in temperature
TCSITEMP [1]	4.7	float	[deg] Telescope center section in temperature
STAIRSU [1]	10.1	float	[deg C] temperature at stairs, upper
TPMNITT [1]	4.8	float	[deg] Telescope mirror NIT temperature
TPMSOBT [1]	4.6	float	[deg] Telescope mirror SOB temperature
TCOWTEMP [1]	0.0	float	[deg] Telescope chimney OW temperature
TTRUWTTT [1]	8.8	float	[deg] Telescope truss WTT temperature
STAIRSL [1]	9.2	float	[deg C] temperature at stairs, lower
WWALLOUT [1]	6.9	float	[deg C] temperature at west wall outside
INAMPS [1]	66.0	float	[A] UPS total input current
DEWPOINT [1]	20.1	float	[deg C] (outside) dewpoint
PMIRTEMP [1]	4.787	float	[deg] Average primary mirror temperature (nit,e
TPR1TEMP [1]	0.0	float	[deg] Telescope probe1 temperature
UTILROOM [1]	9.4	float	[deg C] temperature in utilitiy room
TAIRFLOW [1]	1.121	float	Telescope air flow
WWALLIN [1]	11.2	float	[deg C] temperature at west wall inside
EWALLCOU [1]	7.0	float	[deg C] temperature at east wall, Coude room
BATTERY [1]	100.0	float	[%] UPS Battery left
TGLYCOLI [1]	-2.2	float	[deg] Telescope glycol in temperature
PRESSURE [1]	795.0	float	[torr] (outside) air pressure
DOMSHUTL [1]	not open	str	Lower dome shutter
TCIBTEMP [1]	0.0	float	[deg] Telescope chimney IB temperature
ROOFAMB [1]	7.3	float	[deg C] ambient temperature on roof
SECLEFT [1]	5604.0	float	[s] UPS Seconds left
DOMELUP [1]	12.8	float	[deg C] temperature at dome left, upper
STAIRSM [1]	9.7	float	[deg C] temperature at stairs, mid
TFLOWOUT [1]	10.0	float	Telescope flow rate out
TTRUETTT [1]	8.8	float	[deg] Telescope truss ETT temperature
DOMLIGHH [1]	off	str	High dome lights
TPR2HUM [1]	0.0	float	Telescope probe 2 humidity
TPMEOTT [1]	4.7	float	[deg] Telescope mirror EOT temperature
ALARM-ON [1]	F	bool	UPS active alarm condition
TCOSTEMP [1]	0.0	float	[deg] Telescope chimney OS temperature
THINGES [1]	9.7	float	[deg] Telescope hinge S temperature
TTRSTEMP [1]	9.8	float	[deg] Telescope top ring S temperature
TTRUSTST [1]	10.8	float	[deg] Telescope truss STS temperature
TTRUTSBT [1]	10.2	float	[deg] Telescope truss TSB temperature
TPMSIBT [1]	4.5	float	[deg] Telescope mirror SIB temperature
TTRUETBT [1]	-7.9	float	[deg] Telescope truss ETB temperature
TAIROTMP [1]	3.7	float	[deg] Telescope air out temperature
TPMNOTT [1]	4.9	float	[deg] Telescope mirror NOT temperature
COMPTEMP [1]	22.3	float	[deg C] Computer room hygrometer temperature
ALARM [1]	F	bool	UPS major alarm or check battery
TCIMTEMP [1]	0.0	float	[deg] Telescope chimney IM temperature
TPMWOBT [1]	4.8	float	[deg] Telescope mirror WOB temperature
TPMEIBT [1]	4.6	float	[deg] Telescope mirror EIB temperature
TPMSOTT [1]	4.6	float	[deg] Telescope mirror SOT temperature
TCASOTMP [1]	6.8	float	[deg] Telescope Cass Cage out temperature
GUST [1]	4.5	float	[m/s] Wind gusts speed
TPR2TEMP [1]	0.0	float	[deg] Telescope probe2 temperature
TPMAVERT [1]	4.781	float	[deg] Telescope mirror averagetemperature
DOMEBLOW [1]	11.8	float	[deg C] temperature at dome back, lower
SKYLEVEL [1]	8.153	float	[counts?] ETC sky level

Data: FITS image [float32, 2751x500]

HDU1

EXTNAME = IVAR

Inverse variance (1/sigma^2) of the fiber flat field in HDU0.

Required Header Keywords

Required Header Keywords table

KEY	Example Value	Type	Comment
NAXIS1	2751	int
NAXIS2	500	int
BUNIT		str	inverse variance, adimensional
CHECKSUM	75OIA2LF92LFA2LF	str	HDU checksum updated 2021-07-07T19:21:58
DATASUM	2784291411	str	data unit checksum updated 2021-07-07T19:21:58

Data: FITS image [float32, 2751x500]

HDU2

EXTNAME = MASK

Mask of the fiberflat; 0=good. See the bitmask documentation page for the definition of the bits. Prior to desispec/0.24.0 and software release 18.9, the MASK HDU was compressed.

Required Header Keywords

Required Header Keywords table

KEY	Example Value	Type	Comment
NAXIS1	2751	int	Number of wavelengths
NAXIS2	500	int	Number of spectra (number of rows)
BSCALE	1	int
BZERO	2147483648	int
CHECKSUM	TDeFWDbFTDbFTDbF	str	HDU checksum updated 2021-07-07T19:21:58
DATASUM	687822	str	data unit checksum updated 2021-07-07T19:21:58

Data: FITS image [int32, 2751x500]

HDU3

EXTNAME = MEANSPEC

Average flat lamp spectrum of fibers in this camera frame. The fiber flat field is in first approximation the ratio of the measured spectra to this mean spectrum (in practice we use a deconvolved mean spectrum and reconvolve it with the resolution of each fiber). The units are electrons per Angstrom.

Required Header Keywords

Required Header Keywords table

KEY	Example Value	Type	Comment
NAXIS1	2751	int	Number of wavelengths
BUNIT	electron/Angstrom	str
CHECKSUM	nXJGnXGFnXGFnXGF	str	HDU checksum updated 2021-07-07T19:21:58
DATASUM	2097385325	str	data unit checksum updated 2021-07-07T19:21:58

Data: FITS image [float32, 2751]

HDU4

EXTNAME = WAVELENGTH

Wavelength grid in Angstrom used by this fiber flat field. Note that contrary to the science frame, this wavelength array is in the observer frame. In consequence, one has to first convert its wavelength to the solar barycenter frame before using this data to flat field a science exposure. See the frame WAVELENGTH documentation for more details.

Required Header Keywords

Required Header Keywords table

KEY	Example Value	Type	Comment
NAXIS1	2751	int	Number of wavelengths
BUNIT	Angstrom	str
CHECKSUM	4nG56kG34kG34kG3	str	HDU checksum updated 2021-07-07T19:21:58
DATASUM	2458411755	str	data unit checksum updated 2021-07-07T19:21:58

Data: FITS image [float32, 2751]

HDU5

EXTNAME = FIBERMAP

Fibermap with information about the fiber status.

Required Header Keywords

Required Header Keywords table

KEY	Example Value	Type	Comment
NAXIS1	373	int	length of dimension 1
NAXIS2	500	int	length of dimension 2
ENCODING	ascii	str
CHECKSUM	2imG4ZkE2fkE2ZkE	str	HDU checksum updated 2021-07-07T19:21:58
DATASUM	508954227	str	data unit checksum updated 2021-07-07T19:21:58

Required Data Table Columns

Name	Type	Units	Description
TARGETID	int64
PETAL_LOC	int16
DEVICE_LOC	int32
FIBER	int32
LOCATION	int64
FIBERSTATUS	int32
TARGET_RA	float64
TARGET_DEC	float64
PMRA	float32
PMDEC	float32
REF_EPOCH	float32
LAMBDA_REF	float32
FA_TARGET	int64
FA_TYPE	binary
OBJTYPE	char[3]
FIBERASSIGN_X	float32
FIBERASSIGN_Y	float32
PRIORITY	int32
SUBPRIORITY	float64
OBSCONDITIONS	int32
RELEASE	int16
BRICKNAME	char[8]
BRICKID	int64
BRICK_OBJID	int64
MORPHTYPE	char[4]
EBV	float32
FLUX_G	float32
FLUX_R	float32
FLUX_Z	float32
FLUX_W1	float32
FLUX_W2	float32
FLUX_IVAR_G	float32
FLUX_IVAR_R	float32
FLUX_IVAR_Z	float32
FLUX_IVAR_W1	float32
FLUX_IVAR_W2	float32
FIBERFLUX_G	float32
FIBERFLUX_R	float32
FIBERFLUX_Z	float32
FIBERTOTFLUX_G	float32
FIBERTOTFLUX_R	float32
FIBERTOTFLUX_Z	float32
MASKBITS	int16
SERSIC	float32
SHAPE_R	float32
SHAPE_E1	float32
SHAPE_E2	float32
REF_ID	int64
REF_CAT	char[2]
GAIA_PHOT_G_MEAN_MAG	float32
GAIA_PHOT_BP_MEAN_MAG	float32
GAIA_PHOT_RP_MEAN_MAG	float32
PARALLAX	float32
PHOTSYS	char[1]
PRIORITY_INIT	int64
NUMOBS_INIT	int64
DESI_TARGET	int64
BGS_TARGET	int64
MWS_TARGET	int64
SCND_TARGET	int64
PLATE_RA	float64
PLATE_DEC	float64
NUM_ITER	int64
FIBER_X	float64
FIBER_Y	float64
DELTA_X	float64
DELTA_Y	float64
FIBER_RA	float64
FIBER_DEC	float64
EXPTIME	float64

[1] (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187)

Optional

Notes and Examples

Corrected flux = original flux / fiberflat.

fiberflat = desispec.fiberflat.compute_fiberflat(flatframe)
desispec.fiberflat.apply_fiberflat(scienceframe, fiberflat)