More efficient terrain viewshed computation on massive datasets using external memory
Chaulio R. Ferreira, Salles V. G. Magalhães, Marcus V. A. Andrade, W. Randolph Franklin, André M. Pompermayer · 2012
We present a better algorithm and implementation for external memory viewshed computation. It is about four times faster than the most recent and most efficient published methods. Ours is also much simpler. Since processing large datasets can take hours, this improvement is significant. To reduce the total number of I/O operations, our method is based on subdividing the terrain into blocks which are stored in a special data structure managed as a cache memory.