coordinates-EXPID¶

Summary:: Coordinates data used and produced by fiber positioning, FVC and positioner calibration.
Naming Convention:: coordinates-EXPID.fits, where EXPID is the zero-padded 8-digit exposure ID.
Regex:: coordinates-[0-9]{8}\.fits
File Type:: FITS, 1 MB

Contents¶

Number	EXTNAME	Type	Contents
HDU0	COORDS	IMAGE	Empty HDU
HDU1	DATA	BINTABLE	Coordinates data
HDU2	STATIONARY	BINTABLE	Reference stationary positions

FITS Header Units¶

HDU0¶

EXTNAME = COORDS

This HDU contains header keywords with summary information for the exposure.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type
TILEID	4403	int
TILERA	170.239	float
TILEDEC	-7.093	float
FIELDROT	0.0210480650645507	float
FA_PLAN	2022-07-01T00:00:00.000	str
FA_HA	-6.72	float
FA_RUN	2022-01-03T17:00:31+00:00	str
FA_M_GFA	0.4	float
FA_M_PET	0.4	float
FA_M_POS	0.05	float
REQRA	170.239	float
REQDEC	-7.093	float
FIELDNUM	0	int
FA_VER	5.4.0	str
FA_SURV	main	str
EXPID	103659	int
FLAVOR	science	str
SEQUENCE	DESI	str
GUIDECAM	GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8	str
ACQCAM	GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8	str
GUIDTIME	5.0	float
ACQTIME	15.0	float
FOCUSCAM	FOCUS1,FOCUS4,FOCUS6,FOCUS9	str
FOCSTIME	60.0	float
SKYCAM	SKYCAM0,SKYCAM1	str
SKYTIME	60.0	float
SPCGRPHS	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str
CCDSPECS	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str
ILLSPECS	SP0,SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,SP9	str
OBSTYPE	SCIENCE	str
EXPTIME	None	Unknown
ESTTIME	3705.79	float
MAXTIME	5400.0	float
MINTIME	300.0	float
REQTIME	1860.0	float
MIDTIME	915.0	float
NIGHT	20211010	int
SEQSTART	2022-01-14T11:03:08.447408	str
POSRMS	0.0091	float
TURBRMS	None	Unknown
POSENABL	4268	int
POSDISAB	711	int
POSONTGT	4268	int
POSONFRC		float
POSCVFRC	0.1743	float
POSCYCLE	1	int
POSCNVGD	744	int
CONVERGD	F	bool

Empty HDU.

HDU1¶

EXTNAME = DATA

Data used and produced by the fiber positioning loop.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	240	int	width of table in bytes
NAXIS2	5133	int	number of rows in table

Required Data Table Columns¶

Name	Type	Units	Description
PETAL_LOC	int64		Petal index number
DEVICE_LOC	int64		Index of fiber on petal
POS_Q	float64		TODO: description needed
POS_S	float64		TODO: description needed
POS_FLAGS	float64		TODO: description needed
POS_X	float64		TODO: description needed
POS_Y	float64		TODO: description needed
TARGET_RA	float64	deg	Barycentric right ascension in ICRS
TARGET_DEC	float64	deg	Barycentric declination in ICRS
FA_X	float32		TODO: description needed
FA_Y	float32		TODO: description needed
FA_FIBER	float64		TODO: description needed
FOR_DX_1	float64		TODO: description needed
FOR_DY_1	float64		TODO: description needed
FOR_X_1	float64		TODO: description needed
FOR_Y_1	float64		TODO: description needed
FLAGS_FOR_1	int64		TODO: description needed
FOR_OFFSET_1	float64		TODO: description needed
EXP_Q_1	float64		Expected focal plane Q position after correction move 1
EXP_S_1	float64		Expected focal plane S position after correction move 1
FLAGS_EXP_1	int64		Expected focal plane flags after correction move 1
EXP_X_1	float64		Expected focal plane X position after correction move 1
EXP_Y_1	float64		Expected focal plane Y position after correction move 1
FVC_X_1	float64		FVC position in pixels predicted by PlateMaker after correction move 1
FVC_Y_1	float64		FVC position in pixels predicted by PlateMaker after correction move 1
FLAGS_FVC_1	int64		FVC flags after correction move 1
CNT_X_1	float64		Matched position in FVC pixels after correction move 1
CNT_Y_1	float64		Matched position in FVC pixels after correction move 1
FLAGS_CNT_1	int64		FVC flags on matched position after correction move 1
CNT_MAG_1	float64	mag	FVC estimated magnitude after correction move 1
CNT_ERR_1	float64	mag	FVC estimated magnitude after correction move 1

HDU2¶

EXTNAME = STATIONARY

Refererence stationary fiber positions used when correcting for turbulence.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	358	int	width of table in bytes
NAXIS2	796	int	number of rows in table

Required Data Table Columns¶

Name	Type	Description
PETAL_LOC	int64	Petal index number
DEVICE_LOC	int64	Index of fiber on petal
ZENITH_X	float64	TODO: description needed
ZENITH_Y	float64	TODO: description needed
MODEL_X	char[163]	TODO: description needed
MODEL_Y	char[163]	TODO: description needed
STATCOR_X_0	float64	TODO: description needed
STATCOR_Y_0	float64	TODO: description needed
STAT_X_0	float64	TODO: description needed
STAT_Y_0	float64	TODO: description needed
STATCOR_X_1	float64	TODO: description needed
STATCOR_Y_1	float64	TODO: description needed
STAT_X_1	float64	TODO: description needed
STAT_Y_1	float64	TODO: description needed

Notes and Examples¶

For the SURVEY=cmx m33 tile (TILEID=80615) tile and all the SURVEY=sv1 tiles (except TILEID=80971-80976, the dc3r2 ones), proper-motion correction was applied at the fiberassign design step; thus the following columns can have different values than in the desitarget products: TARGET_RA, TARGET_DEC, REF_EPOCH, PLATE_RA, PLATE_DEC, and PLATE_REF_EPOCH.