STRIPACK: Delaunay triangulation and Voronoi diagram on the surface of a sphere

STRIPACK is a Fortran 77 software package that employs an incremental algorithm to construct a Delaunay triangulation and, optionally, a Voronoi diagram of a set of points (nodes) on the surface of the unit sphere. The triangulation covers the convex hull of the nodes, which need not be the entire surface, while the Voronoi diagram covers the entire surface. The package provides a wide range of capabilities including an efficient means of updating the triangulation with nodal additions,or deletions. For N nodes, the storage requirement for the triangulation is 13N integer storage locations in addition to 3N nodal coordinates. Using an off-line algorithm and work space of size 3N, the triangulation can be constructed with time complexity O(NlogN).