Output Product: HEALPix Footprint Mask

Data product name

VMPZIDHEALPixFootprintMask

Data product custodian

VMPZ-ID

Data model tag

(TBF for ML2A)

Name of the Schema file

(TBF for ML2A)

Schema documentation tag

(TBF for ML2A)

Data product elements

(TBF for ML2A)

Processing Element(s) creating/using the data product

VMPZ-ID, (CM-)PK-WL

Processing function using the data product

LE3

Detailed description of the data product

This output product is essentially the footprint of the survey for a given band/instrument. 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:

  1. DATE-OBS: start of observation with format ‘yyyy-mm-ddThh:mm:ss.sss’ [StringKeyword]

  2. DATE-END: end of observation with format ‘yyyy-mm-ddThh:mm:ss.sss’ [StringKeyword]

  3. TELESCOP: name of the telescope [StringKeyword]

  4. INSTRUME: name of the instrument [StringKeyword]

  5. FILTER: name of the filter [StringKeyword]

  6. FILTLST: selection of filter if intersection of multiple footprints [StringKeyword]

  7. TILEID: identifier of the MER Tile processed (-1 if multiple Tiles) [IntegerKeyword]

  8. LISTID: identifier of a MER list of tiles product (-1 if single Tile) [StringKeyword]

  9. NSIDE_WK: Nside parameter used for frame->HEALPix [StringKeyword]

    and basic software parameters:

  10. SOFTNAME: name of software used [StringKeyword]

  11. SOFTVERS: version of software used [StringKeyword]

Partial HEALPix Footprint Table (First Extension, Binary Table)

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

  1. TTYPE1 (= ‘PIXEL’) [StringKeyword]

  2. TFORM1 (= ‘K’) [StringKeyword]

  3. TTYPE2 (= ‘WEIGHT’) [StringKeyword]

  4. TFORM2 (= ‘E’) [StringKeyword]

  5. PIXTYPE (= ‘HEALPIX’) [StringKeyword]

  6. ORDERING (= ‘RING’ or ‘NESTED’) [StringKeyword]

  7. COORDSYS (= ‘C’=celestial, ‘E’=ecliptic or ‘G’=galactic) [StringKeyword]

  8. EXTNAME (= ‘FOOTPRINT_MASK’) [StringKeyword]

  9. NSIDE [IntegerKeyword]

  10. INDEXSCHM (= ‘EXPLICIT’) [StringKeyword]

  11. OBJECT (= ‘PARTIAL’) [StringKeyword]

The table is then expected to contain the following columns:

  1. PIXEL: index of pixel [K, int64]

  2. WEIGHT: weight associated to pixel in [0,1] indicating the fraction of the pixel actually covered by the footprint (1: fully not observed regions) [E, float32]