ism3d.xyhelper.sky.linear_offset_coords

ism3d.xyhelper.sky.linear_offset_coords(wcs, center)[source]

Returns a locally linear offset coordinate system.

Given a 2-d celestial WCS object and a central coordinate, return a WCS that describes an ‘offset’ coordinate system, assuming that the coordinates are locally linear (that is, the grid lines of this offset coordinate system are always aligned with the pixel coordinates, and distortions from spherical projections and distortion terms are not taken into account)

Parameters

  • wcs (~astropy.wcs.WCS) – The original WCS, which should be a 2-d celestial WCS

  • center (~astropy.coordinates.SkyCoord) – The coordinates on which the offset coordinate system should be centered.