SAR-X Environ - Environmental Mapping Applications Using TerraSAR-X
Remote sensing has become an operational tool in many areas for environmental mapping applications. Main focus so far has been on the use of optical sensors having a strong drawback due to their dependency on cloud coverage. With upcoming commercial radar sensors, research activities revealed a strong potential of radar data for environmental mapping activities. Nevertheless, their use has been restricted due to low resolution. With the launch of TerraSAR-X in 2007, new SAR data have become available, offering high resolution (up to 1 m) and fully polarimetric data for sophisticated mapping applications. Nevertheless, little is yet known about the information content and application potential in environmental land applications.
Development was performed in co-operation with stakeholders on the user side, comprising the Federal Research and Training Centre for Forests, Natural Hazards and Landscape (BFW) in Austria and the Central American Commission for Environment and Development (CCAD) in El Salvador. Experience in research and space science, applied research as well as commercial implementation and application development are the complementary SAR-X Environ project partner assets.
The results of SAR-X Environ comprised assessments of the functional interdependence between surface parameters like surface/terrain roughness and volume scattering of different vegetation types and TerraSAR-X backscattering information.
The project aimed to develop new forest classification approaches with respect to extent, tree species and structural forest parameters using a combination of TerraSAR-X data together with optical EO data (satellite data and orthophotos) and ALS derived surface and terrain roughness layers.
In addition, a land cover change mapping (1999-2008) in Honduras with specific focus on deforestation/afforestation and forest degradation was performed. In the course of this work a state-of-the-art forest module allowing interoperability with several GI processing environments, was developed for increasing processing efficiency.
Second, a methodology for the derivation of a terrain roughness map was developed and tested within the specified test areas in Austria. Results of the roughness classification were crossvalidated with the Federal Research and Training Centre for Forests, Natural Hazards and Landscape (BFW). A high level of thematic accuracy and a high service level prospect for use in different application domains were achieved.
Finally, the methodologies for the derivation of forest extent, forest type and forest parameter maps generated with SAR and optical data and applied in test areas in Austria and Middle America proved to be highly automated and transferrable to other areas.
In the test site Yoro/Honduras it revealed that forest cover change rates exhibit a significant dependence on the management type and this could subsequently be demonstrated in a large area roll-out financed by the World Bank.
GeoVille Information Systems Group GmbH - Jürgen Weichselbaum
- AIT Austrian Institute of Technology GmbH - Klaus Steinnocher
- Vienna University of Technology, Institute of Photogrammetry and Remote Sensing - Prof. Wolfgang Wagner, Markus Hollaus