Metadata extension for gvSIG 2.0

The availability of metadata describing data is fundamental in the world of Geographic Information in order to allow the discovery of and access to geodata. Without metadata to identifiy and define the data, external users will be unable to locate them, even though these data might already be available. The production of metadata associated with the data is a laborious task, one which consumes a great amount of resources and therefore is frequently relegated to a second order of priority, despite its importance. Until now gvSIG offered no metadata manager nor editor, making it difficult to publish the existence of our geodata in Catalogue Services (OpenGIS Catalogue Service).

Therefore, the Metadata extension provides gvSIG with the capability of extracting metadata in a semi-automatic and staged fashion, from a collection of well-known formats of data sources. This makes the documentation of data easier and more efficient. The semi-automatic extraction of metadata means that the manager is capable of collecing some metadata directly from the data source, without user intervention, and provides the user with these descriptions of the data he/she is using. Those metadata that cannot be extracted automatically may be edited manually by the user, using a simple metadata editor, and many of these will not need to be repeatedly edited as they are stored in templates for future use.

The entirety of the metadata manager is created and released under the GPL licence, as is the remainder of gvSIG.

Mission of the project

This project aims to provide gvSIG with a metadata extension that permits users to define their own metadata definitions in order to apply these definitions into layers and other gvSIG metadatable objects.

Objectives

In this project the current gvSIG metadata modules are being implemented following the gvSIG 2.0 architecture. In terms of metadata extraction, it will still be too limited, extracting only the current projection of a layer, for instance. However, a major focus has been done in order to allow users to define their own metadata, and extend layers to that definition, so that they can document their own fields. For that, a basic and a full module have been implemented, so gvSIG users can define their own metadata and edit them. The full version includs import and export functionalities as well.

Project milestones

1. Review of current 1.9 metadata library
2. Design new metadata modules for 2.0 Architecture
3. Provide org.gvsig.tools with DynObject edition functionality
4. Provide a graphic module so that users can interact with this functionality
5. Create a basic metadata module that extends from a DynObject to enable easy user metadata creation. This basic module should be compatible with JavaME and CDC.
6. Create a full metadata module that allows both import and export of metadata objects.

Bibliography

• Metadata Start Guide: (to be announced)
• ISO 19139: http://www.iso.org/iso/catalogue_detail.htm?csnumber=32557