randoms-outside

Summary:: DESI outside-the-footprint random catalogs contain a single binary table covering areas beyond the Legacy Surveys footprint. The columns in this file are simplified compared to the other random catalogs as entries in additional columns would be zeros.
Naming Convention:: randoms-outside-seed-iteration.fits, where seed represents the random seed used to generate the catalog and iteration lists the iteration number of the catalog (several iterations are typically conducted during a given run to generate random catalogs).
Regex:: randoms-outside(-[0-9]+)?-[0-9]+\.fits
File Type:: FITS, 2 GB

Contents

Number	EXTNAME	Type	Contents
HDU0		IMAGE	Empty
HDU1	RANDOMS	BINTABLE	Random catalog table

This HDU has no non-standard required keywords.

Empty HDU.

EXTNAME = RANDOMS

Random catalog table

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	281	int	Width of table in bytes
NAXIS2	1124357626	int	Number of rows in table
DR	9	int	Legacy Surveys (LS) Data Release used to generate randoms
DENSITY	45000	int	Number of random points generated per sq. deg.
SEED	1	int	Seed used to generate supplemental random catalog
ORIGSEED	3	int	Original seed used to generate associated LS random catalog
SUPP	T	bool	`True` if randoms were generated without using LS pixels
RESOLVE	T	bool	`True` if from unique imaging

Name	Type	Units	Description
BRICKID	int32		A unique Brick ID
BRICKNAME	char[8]		Name of the brick
RA	float64	deg	Right ascension at pixel location
DEC	float64	deg	Declination at pixel location
NOBS_G	int16		Number of images at pixel location in LS g (should be zero)
NOBS_R	int16		Number of images at pixel location in LS r (should be zero)
NOBS_Z	int16		Number of images at pixel location in LS z (should be zero)
EBV	float32		Galactic extinction E(B-V) reddening at pixel from SFD98