Daniela Borla Tridon

TanDEM-X: DEM acquisition in the third year era

TerraSAR-X add-on for digital elevation measurement (TanDEM-X) is a space-borne X-band SAR mission designed to derive a digital elevation model (DEM) of the Earth’s land surface with an unprecedented relative vertical accuracy of 2 m at a 12 m posting. To achieve this goal, the two satellites fly in close controlled formation with the opportunity to adjust flexible along- and across-track baselines. A combination of multiple acquisitions with different baseline lengths is required to allow stable phase unwrapping and to achieve the high height accuracy. This paper provides an overview of the TanDEM-X acquisition plan for the third year over Antarctica, mountainous areas and deserts. Critical aspects of the areas to be acquired are presented and the acquisition strategy is illustrated. Moreover, the formation flight and the baselines are compared to the ones of the previous years in terms of their impact on the height of ambiguity and on the performance with respect to the interferometric quality.

TanDEM-X global DEM quality status and acquisition completion

TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurements)is an interferometric SAR mission flying two radar satellites in close orbit formation. Its primary goal is the production of a homogeneous global digital elevation model (DEM) of unprecedented accuracy. Since 2010 all land surfaces have been mapped at least twice and difficult terrain even up to four times. While data acquisition for the DEM generation will be concluded in August 2014 it is expected to complete the processing of the global DEM by the end of 2015. This paper gives a status update on the current acquisition planning and presents quality results from a huge data base of more than 400,000 single DEM scenes and 1700 final DEM products.

TanDEM-X going for the DEM: Acquisition, performance, and further activities

TanDEM-X is an innovative spaceborne X-band SAR mission designed to derive a digital elevation model (DEM) of the Earths land surface with an unprecedented relative vertical accuracy of 2m at a 12m posting. The global DEM is derived from interferometric SAR acquisitions performed by two radar satellites flying in close orbit formation, with adjustable baselines in cross- and in along-track directions. This paper provides an overview of the present mission status in terms of acquisition strategy and a quality summary of the currently available parts of the TanDEM-X global DEM in terms of absolute and relative height accuracy.

Tandem-L observation concept - contributions and challenges of systematic monitoring of earth system dynamics

Tandem-L is a proposal for a spaceborne L-band SAR mission that aims at the global monitoring of dynamic processes on the Earth. The mission will acquire an enormous amount of data for different applications. These data will be used to provide information concerning biosphere, geosphere, cryosphere, and hydrosphere. Within the scope of this mission, an observation concept has to be developed in order to fulfill all the scientific requirements and clarify the necessary system resources. A sophisticated planning and optimization process has been implemented. It combines the predetermined satellite resources, ground station network, and the scientific requirements to generate an acquisition timeline on individual data take level. The resulting timeline fulfills all requirements for the various scientific applications and can be used to analyze different aspects of the mission, e.g. data volumes and orbit usage are necessary to refine the on-board and ground resources.