libera_utils.footprint_matching.geometry.PartialFootprintError

exception libera_utils.footprint_matching.geometry.PartialFootprintError

Raised when the boresight is on Earth but part of the bounding box is not.

At severe viewing zenith angles the footprint stretches so far that the limb-ward corner of its bounding box projects past the Earth’s horizon, even though the boresight still intersects the surface. The box would otherwise silently include a region that is off the Earth.

By default this condition is flagged rather than raised: compute_footprint_bounding_box() truncates the offending rays at the limb and sets BoundingBox.truncated = True (partial coverage). This exception is raised only when the caller opts in with on_limb="raise".

This is a subclass of OffLimbError, so callers that simply except OffLimbError keep working; callers that want to distinguish “no footprint at all” (centroid off-limb) from “footprint clipped by the limb” can catch this subclass specifically.