Sean P. Walker and J. Kenneth Salisbury.
Large Haptic Topographic Maps: Marsview and the Proxy Graph Algorithm.
In Proceedings of the 2003 Symposium on Interactive 3D Graphics, pp. 83--92, 2003.

Bibtex:

@InProceedings{ walker:2003:LHTM,
  author = 	"Sean P. Walker and J. Kenneth Salisbury",
  title = 	"Large Haptic Topographic Maps: Marsview and the Proxy
                  Graph Algorithm",
  booktitle = 	"Proceedings of the 2003 Symposium on Interactive 3D
                  Graphics",
  pages = 	"83--92",
  year = 	"2003",
}