Output Product: MOC Footprint Mask

Data product name

VMPZIDMOCBitMask

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 contains essentially a container for a map for one or more flags in the bitmask as defined in the MER definition.

It includes in BitMaskMOC a container with a FITS file (of type le3.id.vmpz.mocbitmask) describing the flag(s) selected, in MOC HEALPix format (one bit per column), 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). The bit selected is also indicated in the product. Finally, the mask parameters BitMaskMOCParams 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]

  10. BITSEL: identifier of the bit of combination of bits reported in the bitmask (e.g. 0 for least significant bit,..,18) [StringKeyword]

    and basic software parameters:

  11. SOFTNAME: name of software used [StringKeyword]

  12. SOFTVERS: version of software used [StringKeyword]

Partial MOC Footprint Table (First Extension, Binary Table)

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

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

  2. TFORM1 (= ‘K’) [StringKeyword]

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

  4. TFORM2 (= ‘E’) [StringKeyword]

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

  6. ORDERING (= ‘NUNIQ’) [StringKeyword]

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

  8. MOCORDER (best HEALPix order) [IntegerKeyword]

  9. MOCTYPE [StringKeyword]

  10. DATE [StringKeyword]

  11. EXTNAME (= ‘BIT_MASK’) [StringKeyword]

The table is then expected to contain the following columns:

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

  2. WEIGHT: weight associated to pixel in [0,1] indicating the fraction of the pixel actually flagged by the bitN of the mask (1: fully masked regions) [E, float32]

Warning

We have here a solution where we collect just one bit/a combination of bits in the bitmask for a single band of an instrument in a MOC HEALPix file. Note that the conversion frame->HEALPix implies that we lose the binary format if we want the fraction of sky flagged or not in a HEALPix pixel - and therefore we need the single bit products. The alternative is to have a vectorial form, e.g TFORM2=’19E’