Foreword

In 1991 the Spatial Archive and Interchange Format (SAIF, pronounced safe) was accepted as a draft standard for the exchange of geographic data by the Canadian General Standards Board, Committee on Geomatics. Since that time several upgrades have been made, culminating in the current document. SAIF has been approved (1993) through the CGSB process as a national standard in Canada.

The present document, Release 3.1, contains a number of significant changes made in response to two related efforts.

1. The first involves the development of the ISO SQL Multimedia Spatial standard. A new release of SQL, SQL3, is being developed. SQL/MM will be a companion standard. The SQL/MM Spatial is a component of SQL/MM intended to address the management of spatial and spatiotemporal data in the context of database management systems.
2. The second effort concerns the development of the Open Geodata Interoperability Specification (OGIS) under the auspices of the Open GIS Foundation (OGF). The OGF has been designated (1994) by the U.S. Federal Geographic Data Committee as the lead organization responsible for defining an interoperability specification suitable for geoprocessing activities.

Harmonization of SAIF, SQL/MM Spatial and OGIS is leading to a common understanding of geomatics data. Integration with DIGEST and SDTS is also being addressed.

This document describes SAIF in four chapters.

Chapter 1: Technical Overview, including SAIF's design objectives, the major components of SAIF, and the notion of profiles.

Chapter 2: Data Model, consisting of the meta model, data model, modelling paradigm, and schema definitions.

Chapter 3: SAIF Standard Schema, consisting of the definitions of more than 300 data types based on the data model constructs.

Chapter 4: SAIFtalk, including: (i), a class syntax notation, serving as an object oriented data definition language, and allowing users to define their own classes as extensions to SAIF, and (ii), an object syntax notation, permitting the construction of ASCII representations of instances of objects.

Companion documents in the reference series describe binary encoding, SAIF profiles, and the SAIF Toolkit. For further information about Release 3.1 and related materials, please contact:

SAIF Info,
Surveys and Resource Mapping Branch,
B.C. Ministry of Environment, Lands and Parks,
Fourth Floor, 1802 Douglas Street,
Victoria, BC CANADA
V8T 4K6
Tel: (604) 387-1353
Fax: (604) 356-7831