Designing a New Raster Sub-System for GRASS-7

Abstract

The paper deals with a design of a new raster sub-system intended for modern GIS systems open for client and server operation, database connection and strong application interface (API). Motivation for such a design comes from the current state of API working in GRASS 6. If found attractive, the here presented design and its implementation (referred as RG7) may be integrated to the future new generation of the GRASS Geographical Information System version 7-8. The paper describes in details the concept of raster tiling, computer storage of rasters and basic raster access procedures. Finally, the paper gives a simple benchmarking experiment of random read access to raster files imported from the Spearfish dataset. The experiment compares the early implementation of RG7 with the current implementation of rasters in GRASS 6. As the result, the experiment shows the RG7 to be significantly faster than GRASS in random read access to large raster files.

Keywords

• GRASS, GIS, raster sub-system, geographical data, 3D rasters