AN OPENGIS WEB MAP SERVER FOR THE ESA MULTI-MISSION CATALOGUE

This paper describes the development and use of a Web Map Service (WMS) interface to the ESA Multi-Mission Catalogue (MUIS). This interface is compatible with the OpenGIS Consortium (OGC) version 1.1.1 specification so that browse products can be returned as geocoded images in a well-know geographic projection. This will allow them to be displayed on a web browser and merged with other EO and GIS data available from servers already supporting the OGC WMS interface. MUIS contains over 200.000 browse image products from a large number of sensors flying on-board ESA and Third Party Mission satellites. The images represent a wide variety of sensor types, such as SAR, sweep scanners, push-broom scanners and conical scanners. The browse images in MUIS are stored in their original sensors coordinate system. This makes it necessary for the WMS server to rectify them to match the geographic projection requested in a WMS query. This process is performed on-the-fly. The full set of EPSG namespace projection codes are supported in the rectification, in addition to the OGC specified AUTO namespace projections. The rectification is based on a rigorous geometrical model for the space/image acquisition, taking sensor model and orbital constraints into account. The acquisition model is reconstructed from the browse metadata. It also makes orthorectification possible, by using an on-line global DEM. The Open GIS Web Map Server for the MUIS catalogue will enable WMS compatible clients to utilize the ESA products in an easy and standardized way