Tandem-L: Monitoring the Earth's Dynamics with InSAR and Pol-InSAR
Alberto Moreira(1), Gerhard Krieger(1), Irena Hajnsek(1), Kostas Papathanassiou(1), Michael Eineder(1), Francesco De Zan(1), Marwan Younis(1) and Marian Werner(1)
(1) German Aerospace Center, Münchner Strasse 20, 82230 Oberpfaffenhofen, Germany
Tandem-L is a proposal for an innovative interferometric radar mission that enables the systematic monitoring of dynamic processes on the Earth surface. Important application examples are global forest height and biomass inventories, measurements of Earth deformations due to tectonic processes, observations of 3-D structure changes in ice, and the monitoring of ocean surface currents. The innovative mission concept and the high data acquisition capacity of Tandem-L provide a unique data source to observe, analyze and quantify a wide range of mutually interacting processes in the bio-, litho-, hydro- and cryosphere. By this, Tandem-L will be an essential step to advance our understanding of the Earth system and its climate dynamics.
The Tandem-L mission concept relies on a systematic data acquisition strategy using a pair of cooperating L-band SAR satellites flying in close formation. The satellite system is operated in two basic data acquisition modes:
1) The 3-D structure mode employs fully-polarimetric single-pass SAR interferometry (Pol-InSAR) to acquire structural parameters and quasi-tomographic images of volume scatterers like vegetation, sand, and ice.
2) The deformation mode employs repeat-pass interferometry (InSAR) in an ultra-wide swath mode to measure small shifts on the Earth surface with millimetric accuracy and short repetition intervals.
This paper provides an overview of the Tandem-L mission concept and its main application areas. Performance predictions show the great potential of Tandem-L to acquire a wide range of bio- and geophysical products with high accuracy on a global scale. Furthermore, innovative technical aspects like for example the use of digital beamforming to improve performance and coverage will be presented.