lsst.skymap

The skymap package provides tools for creating pixelizations of the sky to define tracts and patches for imaging data.

A sky map describes a pixelization of image data that covers most or all of the sky. The imaging data is arranged as a sequence of overlapping rectangular “tracts”. Each tract is, in essence, a single large exposure. However, tracts are typically too large to fit into memory, so tracts are subdivided into rectangular, possibly overlapping “patches”. The patch size is chosen to easily fit into memory.

Contributing

lsst.skymap is developed at https://github.com/lsst/skymap. You can find Jira issues for this module under the skymap component.

Python API reference

lsst.skymap Package

Functions

makeSkyPolygonFromBBox(bbox, wcs)

Make an on-sky polygon from a bbox and a SkyWcs

Classes

BaseSkyMap([config])	A collection of overlapping Tracts that map part or all of the sky.
BaseSkyMapConfig
BaseTractBuilder(config)	Base class for algorithms that define patches within the tract.
CellInfo(index, innerBBox, outerBBox, …)	Information about a cell within a patch of a tract of a sky map.
CellTractBuilder(config)
DiscreteSkyMap(config[, version])	Discrete sky map pixelization.
DodecaSkyMap([config])	Dodecahedron-based sky map pixelization.
DodecaSkyMapConfig
EquatSkyMap([config])	Equatorial sky map pixelization, e.g.
EquatSkyMapConfig
Index2D	Two dimensional index for patches and cells.
LegacyTractBuilder(config)
PatchInfo(index, innerBBox, outerBBox, …)	Information about a patch within a tract of a sky map.
TractInfo(id, tractBuilder, ctrCoord, …)	Information about a tract in a SkyMap sky pixelization

lsst.skymap.detail Package

Functions

coordFromVec(vec[, defRA])	Convert an ICRS cartesian vector to an ICRS lsst.geom.SpherePoint
makeSkyPolygonFromBBox(bbox, wcs)	Make an on-sky polygon from a bbox and a SkyWcs

Classes

Dodecahedron([withFacesOnPoles])	A dodecahedron with positions of faces and associated vertices.
Index2D	Two dimensional index for patches and cells.
WcsFactory(pixelScale, projection[, …])	A factory for creating Wcs objects for the sky tiles.

Class Inheritance Diagram

lsst.skymap.cachingSkyMap Module

Classes

CachingSkyMap(numTracts[, config, version])

A SkyMap that generates its tracts on request and caches them.

Class Inheritance Diagram

lsst.skymap.healpixSkyMap Module

Classes

HealpixSkyMapConfig	Configuration for the HealpixSkyMap
HealpixSkyMap(config[, version])	HEALPix-based sky map pixelization.

Class Inheritance Diagram

lsst.skymap.ringsSkyMap Module

Classes

RingsSkyMapConfig	Configuration for the RingsSkyMap
RingsSkyMap(config[, version])	Rings sky map pixelization.

Class Inheritance Diagram