SDI: What it Means for Agencies

Author: David Swann
Date: 18 February 2010

Tags: SDI, Spatial Data Infrastructure, data, standards

In this post, I want to talk about some of the effects that implementing a Spatial Data Infrastructure (SDI) will have for agencies. Specifically, the costs and value of SDI to an agency, and the standards needed for an agency to participate in it.

This is the second of three posts introducing SDI in New Zealand. To catch up on my previous SDI update, see:

• SDI: An Introduction

How much will SDI cost my agency? What value will it have?

Within any one agency, the incremental cost to extend an existing system or program of work to participate in SDI will typically be fairly low. But it is important to appreciate that the incremental value to any one system is not huge: SDI is not a panacea that suddenly creates huge value to a program. The real benefit of SDI is in the aggregation across government; small individual benefits aggregating to create significant advantage to New Zealand as a whole.

What standards will my agency need to implement to participate in SDI?

SDI is all about establishing standardised connections between systems, rather than defining how to build systems. So an agency can build systems according to their own business needs, supplier relationships and internal standards. It's how those systems interact with external systems that matters.

• If an agency's systems are to contribute to SDI, they need at a minimum to provide web services using Open Geospatial Consortium (OGC)standards (they may choose to provide a range of other Web 2.0 services such as KML and REST as well). The minimum requirement is to provide a Web Mapping Service (WMS). A Web Feature Service (WFS) will provide much greater capability for consumers and should be regarded as 'highly desirable'.
• Those services have to be discoverable so should be accompanied by ANZLIC profile of ISO 19139 metadata. There are over 40 fields in this profile and the more that can be populated, the more useful that metadata will be. Twelve fields should be regarded as mandatory.
• If an agency's systems are to benefit from SDI, they will need to be able to query metadata portals - ideally using Catalogue Services for Web (CS-W) - and will need to be able to consume OGC services (WMS at a minimum, WFS ideally).
• That's all! SDI resembles the Internet in many respects in that the underlying standards are relatively easy to implement and yet create real benefits.

This post doesn't cover all the benefits or impacts that implementing SDI will have for a participating agency. They'll be different for every organisation, depending on existing systems and business needs, etc. These are just some of the main points each agency will need to be aware of.

What do you see as some of the other gains and impacts for your agency in participating in SDI? Share your thoughts below or contact us.

Coming up, I'll give an outline of some the current thinking and work going on around implementing SDI, and what the roadmap for it might look like.

David Swann