Orthorectification as Preliminary Step for the Fusion of Data from Active and Passive Sensor Systems

One of the main future tasks in the field of reconnaissance and surveillance is the data fusion of heterogeneous systems. For this purpose sensor data of airborne and spaceborne systems, which acquire the data from the same scene, with different spatial and spectral coverage are used. The use of different sensors enables the exploitation and the extraction of information on a higher level, supporting a value adding to the reconnaissance chain, which is especially helpful for the interpretation in urban terrain. A combination of active (SAR, LIDAR) and passive (VIS, IR) sensors is considered. Because of the different imaging properties of the sensor systems it is necessary to transform the datasets into a common coordinate system. For each imaging device a specific transformation equation system is applicable depending on the sensor parameters and supplementary metadata. In this proposal for the used devices the imaging transformation is presented, which allows a common exploitation of the sensor data for the same scenery. An orthorectification method especially for SAR images was developed and applied to airborne SAR data. The spatial accuracy of the transformed sensor data in the common coordinate system is assessed using cadastral data set