This interface to the ERIN Distributed Spatial Data Library [ERIN2] is implemented using an IMAGEMAP imbedded in a Mosaic FORM. In this way thematic and limited spatial queries are possible through the same interface.
This is a workaround solution until a better spatial interface can be associated with WWW clients. See discussion on this matter at Future Requirements.
The user can select a certain type of region, say "STATE", and then either zoom to the region or query what data sets are available for that region using a single mouse click on the image.
Zooming is enabled to a limited set of pre-prepared maps to allow queries to be conducted at a finer level of detail.
Query is effected by selecting one or many themes such as "MARINE" or "CLIMATE", optionally providing additional words to further qualify the query, and then clicking on the image at the appropriate region.
A Common Gateway Interface [CGI] server script written in the perl programming language [perl] picks up the parameters from the FORM and calls the IMAGEMAP program. This works out the geographic location of the mouse click and then calls another CGI script which handles the zoom or query.
Queries may be conducted simultaneously at distributed WAIS servers using yet another CGI script called [SFgate].
A facility is also provided to distinguish between data sets that completely encompass the selected region and data sets that are wholly contained by the region. Partial overlap is harder to cope with and will be addressed in the next version.
A typical query might read like this....
Show all MARINE data sets that pertain to the state of Queensland that mention "reef and pollution". Search for them at the Australian Nature Conservation Agency (ANCA), the Great Barrier Reef Marine Park Authority (GBRMPA), and the ERIN Unit.
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