fiberassign-TILEID.fits¶

Summary:: The fiberassign file contains the fiber positioner configuration information for each exposure: what fiber is placed where, what target that is, etc. The uncompressed version may contain extra HDUs relative to the compressed version.
Naming Convention:: fiberassign-TILEID.fits, where TILEID is the zero-padded 6-digit tile ID.
Regex:: fiberassign-[0-9]{6}\.fits
File Type:: FITS, 42 MB

Contents¶

Number	EXTNAME	Type	Contents
HDU0	PRIMARY	IMAGE	Keywords only
HDU1	FIBERASSIGN	BINTABLE	Target assignments for each fiber
HDU2	SKY_MONITOR	BINTABLE	Sky location for the 20 sky monitor fibers used by the ETC
HDU3	GFA_TARGETS	BINTABLE	Selected star for the ETC / GUIDE / FOCUS
HDU4	TARGETS	BINTABLE	List of targets that are reachable by a positioner
HDU5	POTENTIAL_ASSIGNMENTS	BINTABLE	All possible (TARGETID, FIBER, LOCATION) assignments
HDU6	FASSIGN	BINTABLE	Short version of FIBERASSIGN
HDU7	FTARGETS	BINTABLE	Short version of TARGETS
HDU8	FAVAIL	BINTABLE	Equivalent to POTENTIAL_ASSIGNMENTS

FITS Header Units¶

HDU0¶

EXTNAME = PRIMARY

No data, but some useful header keywords.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Empty HDU.

HDU1¶

EXTNAME = FIBERASSIGN

The target assignments for each fiber of this tile.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	204	int	width of table in bytes
NAXIS2	5000	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
PETAL_LOC	int16		Petal location [0-9]
DEVICE_LOC	int32		Device location on focal plane [0-523]
LOCATION	int32		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
FIBER	int32		Fiber ID on the CCDs [0-4999]
FIBERSTATUS	int32		Fiber status mask. 0=good
TARGET_RA	float64	deg	Barycentric right ascension in ICRS
TARGET_DEC	float64	deg	Barycentric declination in ICRS
PMRA	float32	mas yr^-1	proper motion in the +RA direction (already including cos(dec))
PMDEC	float32	mas yr^-1	Proper motion in the +Dec direction
PMRA_IVAR	float32	yr^2 mas^-2	Inverse variance of PMRA
PMDEC_IVAR	float32	yr^2 mas^-2	Inverse variance of PMDEC
REF_EPOCH	float32	yr	Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia
LAMBDA_REF	float32	Angstrom	Requested wavelength at which targets should be centered on fibers
FA_TARGET	int64		Targeting bit internally used by fiberassign (linked with FA_TYPE)
FA_TYPE	binary		Fiberassign internal target type (science, standard, sky, safe, suppsky)
OBJTYPE	char[3]		Object type: TGT, SKY, NON, BAD
FIBERASSIGN_X	float32	mm	Fiberassign expected CS5 X location on focal plane
FIBERASSIGN_Y	float32	mm	Fiberassign expected CS5 Y location on focal plane
NUMTARGET	int16		Total number of targets that this positioner covered
PRIORITY	int32		Target current priority
SUBPRIORITY	float64		Random subpriority [0-1) to break assignment ties
OBSCONDITIONS	int32		Bitmask of allowed observing conditions
NUMOBS_MORE	int32		Number of additional observations needed
RELEASE	int32		Imaging surveys release ID
BRICKID	int32		Brick ID from tractor input
BRICKNAME	char[8]		Brick name from tractor input
BRICK_OBJID	int32		Imaging Surveys OBJID on that brick
BLOBDIST	float32	pix	Maximum distance from a detected Legacy Surveys source
FIBERFLUX_G	float32	nanomaggy	Predicted g-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_R	float32	nanomaggy	Predicted r-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_Z	float32	nanomaggy	Predicted z-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_IVAR_G	float32	nanomaggy^-2	Inverse variance of `FIBERFLUX_G`
FIBERFLUX_IVAR_R	float32	nanomaggy^-2	Inverse variance of `FIBERFLUX_R`
FIBERFLUX_IVAR_Z	float32	nanomaggy^-2	Inverse variance of `FIBERFLUX_Z`
DESI_TARGET	int64		DESI (dark time program) target selection bitmask
BGS_TARGET	int64		BGS (Bright Galaxy Survey) target selection bitmask
MWS_TARGET	int64		Milky Way Survey targeting bits
PRIORITY_INIT	int64		Target initial priority from target selection bitmasks and OBSCONDITIONS
NUMOBS_INIT	int64		Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS
HPXPIXEL	int64		HEALPixel containing this location at NSIDE=64 in the NESTED scheme

HDU2¶

EXTNAME = SKY_MONITOR

Blank sky assignments for sky monitor positioners.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	113	int	width of table in bytes
NAXIS2	20	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Units	Description
FIBER	int32		Fiber ID on the CCDs [0-4999]
LOCATION	int32		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
NUMTARGET	int16		Total number of targets that this positioner covered
TARGETID	int64		Unique DESI target ID
BRICKID	int32		Brick ID from tractor input
BRICK_OBJID	int32		Imaging Surveys OBJID on that brick
FA_TARGET	int64		Targeting bit internally used by fiberassign (linked with FA_TYPE)
FA_TYPE	binary		Fiberassign internal target type (science, standard, sky, safe, suppsky)
TARGET_RA	float64	deg	Barycentric right ascension in ICRS
TARGET_DEC	float64	deg	Barycentric declination in ICRS
FIBERASSIGN_X	float32	mm	Fiberassign expected CS5 X location on focal plane
FIBERASSIGN_Y	float32	mm	Fiberassign expected CS5 Y location on focal plane
BRICKNAME	char[8]		Brick name from tractor input
FIBERSTATUS	int32		Fiber status mask. 0=good
PETAL_LOC	int16		Petal location [0-9]
DEVICE_LOC	int32		Device location on focal plane [0-523]
PRIORITY	int32		Target current priority
SUBPRIORITY	float64		Random subpriority [0-1) to break assignment ties
FIBERFLUX_G	float32	nanomaggy	Predicted g-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_R	float32	nanomaggy	Predicted r-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_Z	float32	nanomaggy	Predicted z-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_IVAR_G	float32	nanomaggy^-2	Inverse variance of `FIBERFLUX_G`
FIBERFLUX_IVAR_R	float32	nanomaggy^-2	Inverse variance of `FIBERFLUX_R`
FIBERFLUX_IVAR_Z	float32	nanomaggy^-2	Inverse variance of `FIBERFLUX_Z`

HDU3¶

EXTNAME = GFA_TARGETS

GFA stars to be used by the ETC / GUIDE / FOCUS

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	166	int	width of table in bytes
NAXIS2	1873	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Units	Description
RELEASE	int32		Imaging surveys release ID
TARGETID	int64		Unique DESI target ID
BRICKID	int32		Brick ID from tractor input
BRICK_OBJID	int32		Imaging Surveys OBJID on that brick
TARGET_RA	float64	deg	Barycentric right ascension in ICRS
TARGET_DEC	float64	deg	Barycentric declination in ICRS
TARGET_RA_IVAR	float32		label for field 7
TARGET_DEC_IVAR	float32		label for field 8
MORPHTYPE	char[4]		Imaging Surveys morphological type from Tractor
FLUX_G	float32	nanomaggy	Flux in the Legacy Survey g-band (AB)
FLUX_R	float32	nanomaggy	Flux in the Legacy Survey r-band (AB)
FLUX_Z	float32	nanomaggy	Flux in the Legacy Survey z-band (AB)
FLUX_IVAR_G	float32	nanomaggy^-2	Inverse variance of FLUX_G (AB)
FLUX_IVAR_R	float32	nanomaggy^-2	Inverse variance of FLUX_R (AB)
FLUX_IVAR_Z	float32	nanomaggy^-2	Inverse variance of FLUX_Z (AB)
REF_ID	int64		Tyc11,000,000+Tyc210+Tyc3 for Tycho-2; `sourceid` for Gaia DR2
REF_CAT	char[2]		Reference catalog source for star: ‘T2’ for Tycho-2, ‘G2’ for Gaia DR2, ‘L2’ for the SGA, empty otherwise
REF_EPOCH	float32	yr	Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia
PARALLAX	float32	mas	Reference catalog parallax
PARALLAX_IVAR	float32	mas^-2	Inverse variance of PARALLAX
PMRA	float32	mas yr^-1	proper motion in the +RA direction (already including cos(dec))
PMDEC	float32	mas yr^-1	Proper motion in the +Dec direction
PMRA_IVAR	float32	yr^2 mas^-2	Inverse variance of PMRA
PMDEC_IVAR	float32	yr^2 mas^-2	Inverse variance of PMDEC
GAIA_PHOT_G_MEAN_MAG	float32	mag	Gaia G band magnitude
GAIA_PHOT_G_MEAN_FLUX_OVER_ERROR	float32		Gaia G band signal-to-noise
GAIA_PHOT_BP_MEAN_MAG	float32	mag	Gaia BP band magnitude
GAIA_PHOT_BP_MEAN_FLUX_OVER_ERROR	float32		Gaia BP band signal-to-noise
GAIA_PHOT_RP_MEAN_MAG	float32	mag	Gaia RP band magnitude
GAIA_PHOT_RP_MEAN_FLUX_OVER_ERROR	float32		Gaia RP band signal-to-noise
GAIA_ASTROMETRIC_EXCESS_NOISE	float32		Gaia astrometric excess noise
URAT_ID	int64		ID in the URAT catalog for sources where URAT supplemented missing Gaia astrometric information
URAT_SEP	float32	arcsec	Separation between URAT and Gaia sources where URAT supplemented missing Gaia astrometric information
HPXPIXEL	int64		HEALPixel containing this location at NSIDE=64 in the NESTED scheme
GFA_LOC	int16		label for field 35
ETC_FLAG	int16		label for field 36
GUIDE_FLAG	int16		label for field 37
FOCUS_FLAG	int16		label for field 38

HDU4¶

EXTNAME = TARGETS

Unique list of targets reachable by a positioner.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	204	int	width of table in bytes
NAXIS2	145163	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
PETAL_LOC	int16		Petal location [0-9]
DEVICE_LOC	int32		Device location on focal plane [0-523]
LOCATION	int32		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
FIBER	int32		Fiber ID on the CCDs [0-4999]
FIBERSTATUS	int32		Fiber status mask. 0=good
RA	float64	deg	Barycentric Right Ascension in ICRS
DEC	float64	deg	Barycentric declination in ICRS
PMRA	float32	mas yr^-1	proper motion in the +RA direction (already including cos(dec))
PMDEC	float32	mas yr^-1	Proper motion in the +Dec direction
PMRA_IVAR	float32	yr^2 mas^-2	Inverse variance of PMRA
PMDEC_IVAR	float32	yr^2 mas^-2	Inverse variance of PMDEC
REF_EPOCH	float32	yr	Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia
LAMBDA_REF	float32	Angstrom	Requested wavelength at which targets should be centered on fibers
FA_TARGET	int64		Targeting bit internally used by fiberassign (linked with FA_TYPE)
FA_TYPE	binary		Fiberassign internal target type (science, standard, sky, safe, suppsky)
OBJTYPE	char[3]		Object type: TGT, SKY, NON, BAD
FIBERASSIGN_X	float32	mm	Fiberassign expected CS5 X location on focal plane
FIBERASSIGN_Y	float32	mm	Fiberassign expected CS5 Y location on focal plane
NUMTARGET	int16		Total number of targets that this positioner covered
PRIORITY	int32		Target current priority
SUBPRIORITY	float64		Random subpriority [0-1) to break assignment ties
OBSCONDITIONS	int32		Bitmask of allowed observing conditions
NUMOBS_MORE	int32		Number of additional observations needed
RELEASE	int32		Imaging surveys release ID
BRICKID	int32		Brick ID from tractor input
BRICKNAME	char[8]		Brick name from tractor input
BRICK_OBJID	int32		Imaging Surveys OBJID on that brick
BLOBDIST	float32	pix	Maximum distance from a detected Legacy Surveys source
APFLUX_G	float32	nanomaggy	Total flux in nanomaggies extracted in a 0.75 arcsec radius in the g band at this location
APFLUX_R	float32	nanomaggy	Total flux in nanomaggies extracted in a 0.75 arcsec radius in the r band at this location
APFLUX_Z	float32	nanomaggy	Total flux in nanomaggies extracted in a 0.75 arcsec radius in the z band at this location
APFLUX_IVAR_G	float32	nanomaggy^-2	Inverse variance of APFLUX_G
APFLUX_IVAR_R	float32	nanomaggy^-2	Inverse variance of APFLUX_R
APFLUX_IVAR_Z	float32	nanomaggy^-2	Inverse variance of APFLUX_Z
DESI_TARGET	int64		DESI (dark time program) target selection bitmask
BGS_TARGET	int64		BGS (Bright Galaxy Survey) target selection bitmask
MWS_TARGET	int64		Milky Way Survey targeting bits
PRIORITY_INIT	int64		Target initial priority from target selection bitmasks and OBSCONDITIONS
NUMOBS_INIT	int64		Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS
HPXPIXEL	int64		HEALPixel containing this location at NSIDE=64 in the NESTED scheme

HDU5¶

EXTNAME = POTENTIAL_ASSIGNMENTS

A list of targets that could have been assigned to each fiber.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	16	int	width of table in bytes
NAXIS2	163503	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Description
TARGETID	int64	Unique DESI target ID
FIBER	int32	Fiber ID on the CCDs [0-4999]
LOCATION	int32	Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC

HDU6¶

EXTNAME = FASSIGN

Short version of FIBERASSIGN.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	66	int	width of table in bytes
NAXIS2	5020	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Units	Description
FIBER	int32		Fiber ID on the CCDs [0-4999]
TARGETID	int64		Unique DESI target ID
LOCATION	int32		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
FIBERSTATUS	int32		Fiber status mask. 0=good
LAMBDA_REF	float32	Angstrom	Requested wavelength at which targets should be centered on fibers
PETAL_LOC	int16		Petal location [0-9]
DEVICE_LOC	int32		Device location on focal plane [0-523]
DEVICE_TYPE	char[3]		Device type
TARGET_RA	float64	deg	Barycentric right ascension in ICRS
TARGET_DEC	float64	deg	Barycentric declination in ICRS
FA_TARGET	int64		Targeting bit internally used by fiberassign (linked with FA_TYPE)
FA_TYPE	binary		Fiberassign internal target type (science, standard, sky, safe, suppsky)
FIBERASSIGN_X	float32	mm	Fiberassign expected CS5 X location on focal plane
FIBERASSIGN_Y	float32	mm	Fiberassign expected CS5 Y location on focal plane

HDU7¶

EXTNAME = FTARGETS

Short version of TARGETS.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	53	int	width of table in bytes
NAXIS2	145163	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
TARGET_RA	float64	deg	Barycentric right ascension in ICRS
TARGET_DEC	float64	deg	Barycentric declination in ICRS
FA_TARGET	int64		Targeting bit internally used by fiberassign (linked with FA_TYPE)
FA_TYPE	binary		Fiberassign internal target type (science, standard, sky, safe, suppsky)
PRIORITY	int32		Target current priority
SUBPRIORITY	float64		Random subpriority [0-1) to break assignment ties
OBSCONDITIONS	int32		Bitmask of allowed observing conditions
NUMOBS_MORE	int32		Number of additional observations needed

HDU8¶

EXTNAME = FAVAIL

Equivalent to POTENTIAL_ASSIGNMENTS.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	16	int	width of table in bytes
NAXIS2	163503	int	number of rows in table
FA_VER	1.2.1.dev2478	str	Fiberassign code version
FIELDNUM	0	int	Not used, always zero
TILEDEC	28.12	float	[deg] Tile Declination
FA_SURV	main	str	Survey of origin of the targets
TILEID	59096	int	Tile ID
FA_HA	0.0	float	[deg] Design Hour Angle
FIELDROT	0.0	float	[deg] Field rotation
REQRA	348.12	float	[deg] Tile Right Ascension
REQDEC	28.12	float	[deg] Tile Declination
FA_DATE	2022-07-01T00:00:00.000	str	[UTC] Plan field rotations for this date
TILERA	348.12	float	[deg] Tile Right Ascension

Required Data Table Columns¶

Name	Type	Description
LOCATION	int32	Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
FIBER	int32	Fiber ID on the CCDs [0-4999]
TARGETID	int64	Unique DESI target ID