TanDEM-X: A Satellite Formation for High-Resolution SAR Interferometry

• Published in: IEEE transactions on geoscience and remote sensing Vol. 45; no. 11; pp. 3317 - 3341
• Main Authors: Krieger, G., Moreira, A., Fiedler, H., Hajnsek, I., Werner, M., Younis, M., Zink, M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bistatic SAR; Calibration; Collection; Data acquisition; digital elevation model (DEM); Digital elevation models; Discrete element method; Flight; formation flying; Interferometry; microwave remote sensing; Missions; multistatic SAR; Performance analysis; Radar imaging; Radar measurements; Radar satellites; Remote sensing; Satellites; Spaceborne radar; synchonization; Synchronism; synthetic aperture radar (SAR)
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.2007.900693

TanDEM-X (TerraSAR-X add-on for digital elevation measurements) is an innovative spaceborne radar interferometer that is based on two TerraSAR-X radar satellites flying in close formation. The primary objective of the TanDEM-X mission is the generation of a consistent global digital elevation model (DEM) with an unprecedented accuracy, which is equaling or surpassing the HRTI-3 specification. Beyond that, TanDEM-X provides a highly reconfigurable platform for the demonstration of new radar imaging techniques and applications. This paper gives a detailed overview of the TanDEM-X mission concept which is based on the systematic combination of several innovative technologies. The key elements are the bistatic data acquisition employing an innovative phase synchronization link, a novel satellite formation flying concept allowing for the collection of bistatic data with short along-track baselines, as well as the use of new interferometric modes for system verification and DEM calibration. The interferometric performance is analyzed in detail, taking into account the peculiarities of the bistatic operation. Based on this analysis, an optimized DEM data acquisition plan is derived which employs the combination of multiple data takes with different baselines. Finally, a collection of instructive examples illustrates the capabilities of TanDEM-X for the development and demonstration of new remote sensing applications.