I have a dataset coming from weather stations where each vertex used to generate the Voronoi diagram is the lat/long of the station. As such, each cell represents the area whose weather is being reported by the station. I'd like to limit the diameter of each cell to a reasonable distance and generate additional cells for areas with limited coverage. Essentially, for sparsely covered areas I want cells I can associate with either no data or estimated values.

I'm currently using Fortune's algorithm to generate the diagram.

What I'd like to know is what are the standard techniques for:

1. limiting the diameter of a cell,
2. adding points to reduce cell size?

It seems to me that this is a refinement process of either the Voronoi diagram its dual, Delaunay triangulation. The refinement doesn't have to be ideal/optimal, just sufficiently within certain bounds (e.g. within a certain radius of the station's location).