Towards Automating the Selection of Ground Control Points in Radarsat Images Using a Topographic Database and Vector-Based Data Matching.

Users of Radarsat images need ground control points (GCPs) to georeference their images, to rectify them, and to fuse these images. Because the selection of GCPs is usually done manually, the efficiency of the process depends on the ability of the operator to select a GCP. The present paper introduces a new method to automatically identify GCPs in Radarsat images using a topographic database. First, different strategies are elaborated to fit different contexts (topography, cost, availability of data, etc.). These strategies are then grouped in two approaches, i.e., vector-based data matching and raster-based data matching. Both approaches rely on matching feature classes (in ISO/TC211 parlance), e.g., matching "water bodies" or matching "roads intersections" from the image with their equivalent on the topographic database. A user of this method can easily follow the various steps of the GCPs selection process with the support of software tools. This paper presents in detail the method developed to select GCPs with the feature class "water body" and the vector-bused matching approach, and also presents some applications. [ABSTRACT FROM AUTHOR]