fba

Summary:: The fiberassign file contains the fiber positioner configuration information for each exposure for the given randoms.
Naming Convention:: fba-{TILEID}.fits, where {TILEID} is the 8-digit exposure ID.
Regex:: fba-[0-9]{6}.fits
File Type:: FITS, 1 MB

Contents

Number	EXTNAME	Type	Contents
HDU0	PRIMARY	IMAGE	Headers
HDU1	FASSIGN	BINTABLE	Target assignments for each fiber
HDU2	FTARGETS	BINTABLE	List of targets that are reachable by a positioner
HDU3	FAVAIL	BINTABLE	All possible (TARGETID, FIBER, LOCATION) assignments

EXTNAME = PRIMARY

No data, but some useful header keywords

This HDU has no non-standard required keywords.

Empty HDU.

Required Header Keywords Table

KEY	Example Value	Type
TILEID	30	int
TILERA	179.719	float
TILEDEC	-0.016	float
FIELDROT	0.000298543513740412	float
FA_PLAN	2022-07-01T00:00:00.000	str
FA_HA	0.0	float
FA_RUN	2021-04-10T21:28:37+00:00	str
REQRA	179.719	float
REQDEC	-0.016	float
FIELDNUM	0	int
FA_VER	2.3.0	str
FA_SURV	sv3	str

EXTNAME = FASSIGN

The target assignments for each fiber of this tile

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
TILEID	30	int
TILERA	179.719	float
TILEDEC	-0.016	float
FIELDROT	0.000298543513740412	float
FA_PLAN	2022-07-01T00:00:00.000	str
FA_HA	0.0	float
FA_RUN	2021-04-10T21:28:37+00:00	str
REQRA	179.719	float
REQDEC	-0.016	float
FIELDNUM	0	int
FA_VER	2.3.0	str
FA_SURV	sv3	str
DESIDR	edr	str	DESI Data Release

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	Target right ascension
TARGET_DEC	float64	deg	Target declination
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

EXTNAME = FTARGETS

Unique list of targets reachable by a positioner

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	49	int	width of table in bytes
NAXIS2	16584	int	number of rows in table
TILEID	30	int
TILERA	179.719	float
TILEDEC	-0.016	float
FIELDROT	0.000298543513740412	float
FA_PLAN	2022-07-01T00:00:00.000	str
FA_HA	0.0	float
FA_RUN	2021-04-10T21:28:37+00:00	str
REQRA	179.719	float
REQDEC	-0.016	float
FIELDNUM	0	int
FA_VER	2.3.0	str
FA_SURV	sv3	str
DESIDR	edr	str	DESI Data Release

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
TARGET_RA	float64	deg	Target right ascension
TARGET_DEC	float64	deg	Target declination
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

EXTNAME = FAVAIL

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

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	16	int	width of table in bytes
NAXIS2	18420	int	number of rows in table
TILEID	30	int
TILERA	179.719	float
TILEDEC	-0.016	float
FIELDROT	0.000298543513740412	float
FA_PLAN	2022-07-01T00:00:00.000	str
FA_HA	0.0	float
FA_RUN	2021-04-10T21:28:37+00:00	str
REQRA	179.719	float
REQDEC	-0.016	float
FIELDNUM	0	int
FA_VER	2.3.0	str
FA_SURV	sv3	str
DESIDR	edr	str	DESI Data Release

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