Formation flying for along-track interferometric oceanography-First in-flight demonstration with TanDEM-X

Beyond its primary mission objective, the TanDEM-X formation flying mission provides a unique test bed for demonstrating new SAR techniques such as Along-Track Interferometry (ATI) for ocean current measurement. In this paper we discuss the ATI formation control requirements and the limitations imposed by the implemented Helix-formation. We propose two ATI scenarios and verify their feasibility by means of software simulation and in-flight demonstration. In particular, flight results of the very first ATI experiment are presented, demonstrating the high potential of TanDEM-X for mapping ocean currents.