Output Product: HEALPix Footprint Mask¶

Data Product Name¶

DpdHealpixFootprintMaskVMPZ

Data Product Custodian¶

IDVMPZ

Name of the Schema File¶

euc-le3-id-vmpz-HealpixFootprintMask.xsd

Last Edited for DPDD Version¶

2.0

Processing Elements Creating / Updating / Using the Product¶

Creators:

VMPZ_Main (LE3_VMPZ_ID_Main)

Consumers:

VMPZ_Visibility (LE3_VMPZ_ID_Visibility)

Processing function using the data product¶

2PCF-WL, PK-WL, 2PCF-GC, 3PCF-GC, PK-GC, DET-CL, PROF-CL, VMSP-ID
SWG-GC, SWG-WL, SWG-CL

Proposed for inclusion in EAS/SAS¶

This product is proposed for inclusion in SAS: yes

This product is used by different PFs in OU-LE3 and expected to be used in scientific analysis in SWG-GC, SWG-WL and SWG-CL.

Data Product Elements¶

Header:: object of type sys:genericHeader
Data:: object of type vmpzid:footprintMaskHealpixVMPZ
QualityFlags:: object of type dqc:sqfPlaceHolder
Parameters:: object of type ppr:genericKeyValueParameters

Detailed Description of the Data Product¶

This output product is essentially the footprint of the survey for a given band/instrument. This product is equivalent to apply weights > 0 on the coverage mask.

The FootprintMaskHealpix metadata includes a container with a FITS file (of type le3.id.vmpz.healpixfootprintmask) describing the footprint for the survey in partial HEALPix format, for a given observed band/instrument (Euclid/EXT), and a raw description with polygons of the envelope of the sky covered is added as well to ease future queries on the product (SpatialCoverage metadata, see spatialFootprint). Finally, the mask parameters FootprintMaskHealpixParams can optionally be associated to the product.

Keywords (Primary HDU)¶

The primary HDU is expected to contain the following keywords, characterizing important parameters of the input product:

HDU PRIMARY: header
	Name	Description	Value
Keywords	SIMPLE		logical
	BITPIX		integer
	NAXIS		integer
	EXTEND		logical
	DATE-OBS	e.g. Start date for observations considered	string
	DATE-END	e.g. End date for observations considered	string
	TELESCOP	e.g. Euclid or -1	string
	INSTRUME	e.g. VIS or -1	string
	FILTER	e.g. VIS or -1	string
	FILTLST	index for combination of filters if intersection of footprints	string
	TILEID	e.g. 5237, or -1 if not single tile	integer
	LISTID	Product ID for a MER list of tiles	string
	NSIDE_WK	Nside used for mosaic;frame to HEALPix	string
	BITSEL	e.g. Bit mask selection applied based on MER binary values	string
	SOFTNAME		string
	SOFTVERS		string
	SOFTINST		string

Some Keyword not in FDM #. FILTLST: selection of filter if intersection of multiple footprints [StringKeyword] #. TILEID: identifier of the MER Tile processed (-1 if multiple Tiles) [IntegerKeyword] #. LISTID: identifier of a MER list of tiles product (-1 if single Tile) [StringKeyword] #. NSIDE_WK: Nside parameter used for frame->HEALPix [StringKeyword] #. BITSEL: combination of bits reported in the bitmask (32 binary digits, each 0 or 1,

following the standard most significant bit first convention) [StringKeyword] and basic software parameters:

SOFTNAME: name of software used [StringKeyword]
SOFTVERS: version of software used [StringKeyword]
SOFTINST: institute developing the software [StringKeyword]

Partial HEALPix Footprint Table (First Extension, Binary Table)¶

The following keywords are used to describe what HEALPix conventions are followed:

HDU FOOTPRINT_MASK: header
	Name	Description	Value
Keywords	XTENSION		string
	BITPIX		integer
	NAXIS		integer
	NAXIS1		integer
	NAXIS2		integer
	PCOUNT		integer
	GCOUNT		integer
	TFIELDS		integer
	TTYPE1		string
	TFORM1		string
	TTYPE2		string
	TFORM2		string
	TTYPE3		string
	TFORM3		string
	PIXTYPE		string
	ORDERING		string
	COORDSYS		string
	EXTNAME		string
	NSIDE		integer
	INDXSCHM		string

HDU FOOTPRINT_MASK: 3 columns table
	Name	Description	Unit	Format
Columns	PIXEL	Index of the HEALPix pixel cell	NA	FITS K
	WEIGHT	Mask value, ranging from O to 1	NA	FITS E
	ERROR	Mask error value	NA	FITS E

TTYPE1 (= ‘PIXEL’) [StringKeyword]
TFORM1 (= ‘K’) [StringKeyword]
TTYPE2 (= ‘WEIGHT’) [StringKeyword]
TFORM2 (= ‘E’) [StringKeyword]
PIXTYPE (= ‘HEALPIX’) [StringKeyword]
ORDERING (= ‘RING’ or ‘NESTED’) [StringKeyword]
COORDSYS (= ‘C’=celestial, ‘E’=ecliptic or ‘G’=galactic) [StringKeyword]
EXTNAME (= ‘FOOTPRINT_MASK’) [StringKeyword]
NSIDE [IntegerKeyword]
INDEXSCHM (= ‘EXPLICIT’) [StringKeyword]

The table is then expected to contain the following columns:

PIXEL: index of pixel [K, int64]
WEIGHT: weight associated to pixel (0 or 1) indicating the fraction of the pixel actually covered by the footprint (1: fully not observed regions) [E, float32]