THE PYRAMID SYSTEM FOR MULTISCALE RASTER ANALYSIS

Geographical research requires the management and analysis of spatial data at multiple scales. As part of the U.S. Geological Survey's globa l change research program a software system has been developed that re ads raster data (such as an image or digital elevation model) and prod uces a pyramid of aggregated lattices as well as various measurements of spatial complexity. For a given raster dataset the system uses the pyramid to report: (1) mean, (2) variance, (3) a spatial autocorrelati on parameter based on multiscale analysis of variance, and (4) a monof ractal scaling parameter based on the analysis of isoline lengths. The system is applied to 1-km digital elevation model (DEM) data for a 25 6-km(2) region of central California, as well as to 64 partitions of t he region. PYRAMID, which offers robust descriptions of data complexit y, also is used to describe the behavior of topographic aspect with sc ale.