PROVIDING SPATIAL DATA SUPPORT AND ACCESS TO FREELY AVAILABLE SATELLITE IMAGERY FOR THE UK ACADEMIC COMMUNITY - A REVIEW OF DATA ACQUISITION AND DATA DELIVERY INFRASTRUCTURE

摘要

The Satellite Image Data Service (SIDS) is now freely available to all UK licensed institutes. The data archive currently consists of a 25m Digital Elevation Model (DEM), ERS 1 & 2, ENVISAT ASAR and MERIS, Landsat 5 & 7, Kinematic Global Positioning Sytem (KGPS) survey and SPOT. Continued funding from the Joint Information System Committee (JISC) for a further five years has enabled the SIDS to order annual acquisitions of optical data and biannual acquisitions of radar for the whole of the UK. Possible new datasets for future acquisition will be discussed in the first part of this paper. The SIDS is committed to investigating innovative methods of providing data delivery to service users; this enables users to efficiently interoperate SIDS data with other spatial data resources. The second part of this paper will cover recent service infrastructure developments e.g. Image Streaming Service, Open Geospatial Consortium (OGC) services, KML and Grid. The SIDS is keen for users to take advantage of the 3D visualisation capabilities of Google Earth and a KML file has been produced which connects to the Image Streaming service. In addition the Grid Enabling MIMAS Services (GEMS) II Project has commenced which aims to demonstrate a use case scenario (urban/rural change detection) using Landsat 5, Landsat 7 and DEM data on the Grid for computer intensive image processing tasks. The GEMS II Project will use the OGC Web Processing Service (WPS) specification as well as the Catalogue Service and Web Coverage Service (WCS). The workflow will be for a user to interact with a client, consulting a catalogue service, deciding on data requirements, then deciding what processes are required to be done on the data (WPS), at which stage a WCS request will deliver the data to the compute node.