CAN/CGSB-171.1-95

1.1 High Level Design Objectives The Spatial Archive and Interchange Format was developed as a means of sharing spatial and spatiotemporal data. SAIF's primary objectives are as follows: 1. it must be appropriate for modelling and moving data in general; that is, it should be able to deal with both spatiotemporal and traditional information, 2. it must handle virtually any kind of geographic data, including those: (i), with or without extensive attribute descriptions, and (ii), with geometry defined by vector or raster structures in two or three dimensions, (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 and relationships can be handled (e.g., moving oil spills, vehicle navigation, general monitoring activities), 4. it must address data management requirements (such as support for updates, ability to integrate with multimedia data, applicability to both large and small data volumes, the ability to interface well with database queries, and compatibility with catalogue developments), 5. it must be suitable for effective operations in network environments, as well as appropriate for conventional file transfer on magnetic or optical media, 6. it must be easy to use and cost effective, and it must be easy to maintain and extend in response to users' needs and changing technology (without demanding major investments on the part of the data providers or data users), 7. it should harmonize with new SQL database developments and open GIs initiatives, as well as other geographic standards such as DIGEST and SDTS. SAIF is designed to facilitate interoperability, particularly in the context of data exchange. It also represents an efficient means of archiving data in a vendor neutral format. An overriding consideration with SAIF is to be able to treat geographic data as simply another kind of data; that is, the roots of SAIF are in the information sciences.