Data sets mostly within bounding box (Default)
Provides a search for data sets that fall mostly within the bounding box
specified by the geographic coordinates.

Data sets completely within bounding box
Provides a search for data sets that are completely within the bounding box
specified by the geographic coordinates.

Intersects with the bounding box (includes global data sets)
Provides a search for data sets that intersects with the bounding box
specified by the geographic coordinates. This search will include global or near global data sets in the results.

The spatial search constraint algorithms were provided to NASA/GCMD by Mark Harwood at InPerspective .