171-GP-1P

High Level Design Objectives The Spatial Archive and Interchange Format was developed as a means of sharing any information which can be referenced to the earth. SAIF's primary objectives are as follows: 1) it must be appropriate for modelling and transferring virtually any data of interest; that is, it must be practical to use with both geographic and non-geographic information, 2) it must handle a broad range of types of spatial data, including those associated with vector and raster structures in two and three dimensions, and which may or may not have extensive attribute descriptions (e.g., typical topographic, cadastral, and thematic data, but also, subsurface geologic data, climate data, hydrographic data, etc.), 3) it must address time such that temporal events can be handled (e.g., moving oil spills, vehicle navigation, general monitoring activities), 4) it must be able to deal with updating and other data management requirements (such as small data volume size and the ability to interface well with database queries), 5) it must be suitable for operations in telecommunications environments, as well as appropriate for conventional file transfer on magnetic or optical media, 6) it must be easy to use and cost effective (without demanding major investments on the part of the data providers or data users), 7) it must be easy to maintain and extend in response to users' needs and changing technology (with minimal impact to existing SAIF users). SAIF is designed to facilitate data exchange and to help users understand each other's data. It also represents an efficient means of archiving data in a vendor neutral format.