For a celestial WCS (see astropy.wcs.WCS.celestial) returns pixel area of the image pixel at the CRPIX location once it is projected onto the “plane of intermediate world coordinates” as defined in Greisen & Calabretta 2002, A&A, 395, 1061.
Note
This function is concerned only about the transformation “image plane”->”projection plane” and not about the transformation “celestial sphere”->”projection plane”->”image plane”. Therefore, this function ignores distortions arising due to non-linear nature of most projections.
Note
In order to compute the area of pixels corresponding to celestial axes only, this function uses the celestial WCS object of the input wcs. This is different from the proj_plane_pixel_scales function that computes the scales for the axes of the input WCS itself.
Parameters: | wcs : WCS
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Returns: | area : float |
Raises: | ValueError |
Notes
Depending on the application, square root of the pixel area can be used to represent a single pixel scale of an equivalent square pixel whose area is equal to the area of a generally non-square pixel.