The use of Service Oriented Architectures (SOA) and, more specifically, Spatial Data Infrastructures (SDI) has grown significantly over the last few years, delivering maps, imagery and other geospatial data online as services and for download. Many government institutions are making available open data and have rushed to set up SOA/SDI environments… often only to deliver the result to the user only via a specific geospatial portal. As a result, the geospatial portal is often becoming the new stovepipe, with systems unable to effectively chain onto a service platform, The users are left with a myriad of geospatial portals, each with different interaction styles, to search through to get to the geospatial data they want.
… the geospatial portal is often becoming the new stovepipe, with systems unable to effectively chain onto a service platform
Custom Geospatial Portal
I am sure I am not the only person that has had to suffer these bespoke geospatial portals, navigating their specific query models, and download tools. Many of the portals are well designed, but the point is I really don’t want to learn how to use a new one for every provider of open source data. Nor do I want to spend hours selecting the data I am interested in manually.
The OGC ISO19115/119 Application Profile of Catalogue Services for the Web (CSW) Service definition is a perfectly good and functional standard for the discovery of basic geographic information. CSW is implemented by a number of Open Source projects (including GeoNetwork and PyCSW), just waiting to provide machine-readable catalogues. We have slowly seen the addition of basic OGC compliant catalogue services such as those used by EU INSPIRE and GEOSS using CSW-ISO, but many organisations are shunning them leaving us with the custom portal they provide as the only way to get at their data.
Custom Geospatial APIs
Probably as bad as dealing with the custom portal, is the tendency for organisations to offer ‘their own web API’ which you can use to search on. But this means if you are to avoid an organization’s portal, you have to get your developers to build a specific interface for each provider. This then often is not financially viable and you soldier on with the specific portal. Some organisations claim to have far more complex and diverse data sources to manage and deliver. Data may be versioned, with change history being important, and may include multiple time and position dimensions such as in meteorological data, live track feeds or full motion video.
Data may be derived from multiple community sources; in this situation, there may be multiple taxonomies, symbolizations and styles to mediate to ensure effective access to information by all users in the enterprise. But again, these requirements are pretty much covered by the more advanced OGC Catalogue standard CSW-ebRIM (Electronic Business Registry Information Model).
Instead of implementing this perfectly workable standard, organisations seem to invent more yet complicated APIs to access their data. Or, they try to deliver catalogue services through a range of other existing standards with geospatial information searchable only in a bespoke way. Picking an especially obscure standard or even using other OGC Standards such as the Web Feature Server (WFS) as a catalogue means there is little or no chance of general interoperability with the rest of the geo community.
Envitia Applies Open Standards
Envitia, an active OGC technical member, applies both of the OGC Catalogue standards, CSW-ISO and CSW-ebRIM and we question why organisations, even organisations which support other OGC standards such as WMS, seem to continually ignore the OGC Catalogue standards. If every government agency that provided open data supported one of the OGC CSW Standards (and it is not that hard to support both) then it would massively increase the accessibility and exploitation of open data in many geo-related communities. And we would all not have to go through the rack of tedium in trying to get at a set of open geospatial data to use in our own innovative new applications.