Stakeholders involved in distributing and accessing geospatial data agree that the first stage in achieving this goal is documenting data sets or creating metadata. Organisations handling standards (FGDC, ISO/TC211, OpenGIS) have identified metadata as a priority in their work and geospatial data infrastructures such as the Canadian Geospatial Data Infrastructure (CGDI) often start with the implementation of services related to metadata (discovery, evaluation, access).
However, the gathering of metadata is often a tedious and frustrating task that has to be performed on top of data management in spatial warehouses. Metadata standards are complex and cannot be readily applied to data managed in spatial warehouses where a data set can be defined as any object.
Intelec has developed, under a GeoInnovations project, a multi-standard, multilingual metadata cataloguing tool: the M3Cat. CubeWerx and SoftMap also provide warehouse products to manage geospatial data. With their products, the three companies aim to improve metadata collection and management to facilitate the presence of their clients on the CGDI.
The following figure illustrates the current situation concerning integrated management of data and metadata. Briefly, data warehouses (and GIS) store data, and manage this data using a small amount of metadata. Other programs man age the bulk of this data using metadata and therefore allowing the client to find, comprehend, and access the data more efficiently. At the moment, there are no ways for updates that occur in the data sets to be translated into the metadata management programs, and vice versa.
The project objectives were to develop tools that allow the integration of metadata servers in a Web environment using protocols similar to OpenGIS standards. These tools, available as an Integrated Web Catalogue (IWCat) service, allow:
- the update of metadata in M3Cat from catalogues in data warehouses (CubeSTOR, SoftMap);
- queries to catalogues in data warehouses from M3Cat;
- queries to M3Cat from data warehouses.
The project outcomes were :
- an exchange Protocol between M3Cat, CubeSTOR and SoftMap;
- a new version of M3Cat;
- additional tools in CubeSTOR;
- additional tools in SoftMap.
- suppliers will be able to:
- update their metadata catalogues from their data warehouses;
- propagate metadata updates from a data set to all the objects it contains;
- improve the connection of their metadata to the CGDI.
- users will be able to:
- query additional information on the data from data warehouses;
- identify, when querying the CGDI, available data sets and specific data elements (concept of evolution from a data set to the information).
Because the management of metadata becomes faster and more efficient with IWCat, suppliers can devote more time to the improvement of their data. In this way, more time can be devoted to gathering new data, increasing data precision, and adding updates.
Because searches of metadata are intricately linked to the data sets, users can better discover the data of interest, which will be of better quality and will be better documented. This ensures a more efficient use in the users’ fields (forestry, mines, etc ...).
The project was a good example of partnerships between the Federal Government, Provincial Governments, the Private Sector and Universities.
The IWCat service was developed by Intelec and its partners CubeWerx, SoftMap Technologies and the Centre for Research in Geomatics (CRG) of Laval University. It has been tested with six governmental organisations involved in the management of geospatial data:
- the Department of National Defence;
- Environment Canada;
- the Canadian Centre for Remote Sensing;
- the Canadian Forest Service;
- the Earth Sciences Sector of Natural Resources Canada;
- the Quebec Ministry of Natural Resources.