Geomatics Technology for CERES

Problem

CERES will provide province and state-wide access to environmental information of all types, housed in a variety of information management systems. For this information to be useful to users, it must be organized and presented in a consistent, coherent structure. Current systems for network browsing are limited to a very simple set of presentations - ie text files, raster graphics, and possibly audio/video clips.

Even the more sophisticated browsers such as Mosaic do not provide datasets to users in a form suitable to further analysis or explorations. WAIS adds capabilities for spatial query and basic geoprocessing (clip, select, etc), though at the expense of multi-media capabilities. In all cases, the information presented to users is in the form originally created by the data developer. For geographic information, this means coverages in a particular data structure (eg, Arc/Info, GRASS, Genamap, etc). More importantly for effective use, it means the data dictionary describing the content of the coverage, the attributes assigned to specific features, and the catalog of attribute definitions are all determined by the data provider.

Full disclosure of data structure types and attributes is a necessary component of information understanding, but it is insufficient for purposes of detailed analysis, using the tools the user may have at hand, without significant processing of the data into a common, canonical form. Moreover, a priori knowledge of data structure and content does not support dataset integration or provide the mechanisms for cross-comparison of divergent types. That is, information collected in response to a specific query may be too diverse to allow direct comparison without significant post-processing.

Example: A query for information about landcover within the drainages of Lake Tahoe could result in a vegetation polygon coverage using the Anderson land classification, a classified Thematic Mapper image derived from bands 1,2, and 4, and a stream network with gage observations at a set of latitude/longitude points. Associating specific landcover types with observed spectral response, and extrapolating those associations to other areas for comparison with stream flow, would require the user to convert all three datasets to a common format and implement a common schema covering all three datafiles.

Objectives

The overall goal of CERES is to craft an architecture for geographic information sharing that enables users to locate, access, visualize, query, and analyze heterogeneous geospatial data across a network. The resulting system must support both high-level browsing and integration of selected data into a common framework for complex queries and analyses.

The following objectives must be realized for this goal to be achieved:

A high-level architectural view shows the relation among different datastores, catalogs, and interface protocols.

The end product will be a set of tools and procedures that utilizes the protocols and technology of the Open GIS Interoperability Specification (OGIS) to advance the functionality of CERES. Specifically, this effort will create an OGIS environment for CERES -- a somewhat more detailed statement of the specification that focusses on the data cataloguing, modeling, and presentation requirements of CERES. Within this environment, will be constructed a series of locales that provide the substantive functionality needed within each of the CERES bioregions.

Strategic Plan

The CERES environment and its member locales will be designed and implemented in a series of stages: