Checks if a map contains any part of the solar limb or equivalently whether the map contains both on-disk and off-disk pixels.
The check is performed by calculating the angular distance of the edge pixels from the center of the Sun. If at least one edge pixel is on disk (less than the solar angular radius) and at least one edge pixel is off disk (greater than the solar angular distance), or the map contains the full disk, the function returns
True. Otherwise, the function returns
GenericMap) – A map in helioprojective Cartesian coordinates.
For coronagraph images such as those from LASCO C2 and C3 the full disk is within the field of view of the instrument, but the solar disk itself is not imaged. For such images this function will return