OSGeo Journal

Satellite imagery provides a large amount of useful information. To extract this information and understand them may require huge computing power and processing time. Distributed computing can reduce the processing time by providing more computational power. GRASS, an open source software, has been used for processing the satellite images. To let the GRASS modules benefit from distributed computing, an example module r.vi is ported in both MPI (r.vi.mpi) and Ninf-G (r.vi.grid) programming modules. Their implementation methodologies are the main discussion issue of this paper which will guide the basic way of representing any GRASS raster module in distributed platform. Additionally, a comparative study on modified r.vi, r.vi.mpi and r.vi.grid is presented here. Introduction Satellite image processing plays a vital role for research developments in Remote Sensing, GIS, Agriculture Monitoring, Disaster Management and many other fields of study. However, processing those even increasing spatial resolution satellite images require a large amount of computation time due to its complex and large processing criteria. This seems a barrier for real time decision making. Distributed computing can be a suitable solution to complete the job timely. Cluster and Grid are two well-known distributed systems have been associated with high performance computing of massive CPU bound applications. GRASS GIS (Neteler et al. , 2004) is an open source software/tool, which has been used to process satellite images. Inside GRASS, different modules have been developed for processing satellite images. GRASS module r.vi is developed by (Kamble et al. , 2006), and is used as a test example for this study. Developing the methodology, which enables to run GRASS GIS environment for satellite image processing on distributed computing systems, is the main concerning issue of this paper. Additionally, two different implementation methodologies for distributed r.vi are discussed for two different programming platforms MPI (Message Passing Interface