A Geometric Simulator for the Hyperspectral Mission Enmap

The hyperspectral satellite EnMAP (Environmental Mapping and Analysis Program) is scheduled to launch in 2014. It is a joint project by the GFZ (Deutsches GeoForschungsZentrum), the DLR (German Aerospace Center), Kayser-Threde and OHB-System. Apart from the project management, the DLR is responsible for the development of the ground segment for EnMAP. One of the key steps of the developed processing chain is the geometric correction of the EnMAP data. As EnMAP uses an in-field separation design, corresponding areas on the Earth are imaged with a time delay of approximately 88 ms. This in combination with attitude controller errors, board instrument vibrations as well as external effects, such as the rotation of the Earth, leads to co-registration inaccuracies between the VNIR and SWIR data. As it is not possible to correct this error by imager design, it has to be corrected after the image acquisition during the geometric correction step. To be able to test and validate if the desired co-registration accuracy of 0.2 pixels can be achieved using the developed geometric processor, a geometric simulator was implemented. The simulator design as well as the co-registration results achieved by the geometric correction are discussed in this paper.