supplemental skies¶

Summary:: The subpriority files are single binary tables that include the fixed values of subpriority enforced for Main Survey targets. There is one file for each of dark-time and bright-time targets, and one for blank sky locations.
Naming Convention:: subpriorities-TTYPE.fits, where TTYPE is one of dark, bright or sky.
Regex:: subpriorities-[a-zA-Z]+\.fits
File Type:: FITS, 41 - 360 MB

Contents¶

Number	EXTNAME	Type	Contents
HDU0		IMAGE	Empty
HDU1	SUBPRIORITY	BINTABLE	Per-target SUBPRIORITY values

This HDU has no non-standard required keywords.

Empty HDU.

EXTNAME = SUBPRIORITY

Per-target SUBPRIORITY values

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	24	int	width of table in bytes
NAXIS2	2026104	int	number of rows in table
FAPRGRM	“bright”	str	one of “dark”, “bright” or “sky”
INFIL000	“$DESI_ROOT/”	str	zeroth fiberassign file/tile for which fixed SUBPRIORITY values need to be enforced
INFIL001	“$DESI_ROOT/”	str	first fiberassign file/tile for which fixed SUBPRIORITY values need to be enforced
INFILxxx	“$DESI_ROOT/”	str	etc.

Name	Type	Description
TARGETID	int64	Unique targeting ID
SUBPRIORITY	float64	Random subpriority [0-1] to break assignment ties
DESI_TARGET	int64	DESI (dark time program) target selection bitmask