The supplementary R-tree (SRT) algorithm used for GIS resources allocation in model base system under grid environment

This model base system (MBS) is a computer software system which classify and maintain a great number of models, and support generation, storage, query, running and analysis of models, and the term of Grid refers to a system that enables the integrated, collaborative use of high-end computers, networks, databases, and scientific instruments owned and managed by multiple organizations. Model base system (MBS) for GIS (geographic information system) application in grid, usually utilizes the LDAP (lightweight directory access protocol) to manage the distributed GIS resources in grid. It is imperative to create index rules for the resources location. The paper is mainly about the effective algorithm to create spatial index used for locating GIS resources in grid. Similar to the usage of most GIS spatial database, we use the MBR (minimized boundary rectangle) as the indexed value keys, and push them in a new data structure of R-tree, named the supplementary R-tree, and find that it´s relatively more efficient in seeking and querying spatial data than the other algorithm, such as grid map file (GMF) and R- tree.