Long-Term Evolution and Current Status of TerraSAR-X and TanDEM-X

Abstract

TerraSAR-X and its almost identical twin satellite TanDEM-X continue to acquire high resolution radar images and digital elevation models with unprecedented accuracy far beyond their expected lifetime. Since launch the SAR image quality and resolution have remained constant which is owed to a very stable instrument but also to an elaborate ground segment. As a result, the bistatic mission, which was designed for 5.5 years to generate a single global digital elevation model, could be extended. In the following and still ongoing TanDEM-X 4D phase, constant updates of the global dataset are acquired showing in particular the three-dimensional elevation and terrain changes over time. Since both satellites are still in good condition, the ongoing missions will be continued providing continuous extension of this unique dataset. In order to validate the good condition of both satellites and give an outlook on the remaining lifetime expectancy, this paper will give a detailed overview of the current status of the satellites’ systems, the remaining onboard consumables and the implemented strategies to extend their lifetime while maintaining the image quality.