Registration of satellite imagery
Automatic registration of satellite imagery to aerial orthophotos
Accurately geo-registering satellite imagery involves significant costs driven by the need to capture Ground Control Points (GCPs) – a time-consuming, manually intensive and highly subjective activity. For large-scale operational activities, the high cost, lack of timeliness and lack of repeatability are critical issues. One application where these are particularly pronounced is in the European Commission’s use of satellite imagery to follow up agricultural subsidy claims. The potential role of the satellite data in claim disputes requires the highest geometrical integrity, while the increasing role of very high-resolution (VHR) imagery demands ever more accurate and costly GCPs.
VHR imagery requires effective and consistent ways to capture GCPs that are accurate down to the sub-metre level. Pre-existing aerial orthoimages can offer a valuable source of such information through automated georeferencing of the VHR imagery to the airborne imagery. This requires an operationally reliable and robust approach to achieve a substantial rationalisation of the orthocorrection process.
Spacemetric specialises in methods that provide an automatic geo-referencing of imagery based on a priori acquisition parameters. The initial model can be enhanced by geometric registration to reference material. The REGISTRATION project aims to develop techniques to register VHR imagery to aerial orthophotos in an operationally robust way. The work will be carried out over a number of test sites within the European Union in cooperation with the Joint Research Centre in Ispra, the Commission body that provides overall coordination of the subsidy control activities with satellite imagery.
Lars-Åke Edgardh, Spacemetric, email@example.com
25 maj 2009