ABSTRACT
The Wadden Sea on the continental North Sea coast is the world’s largest coherent intertidal area, and it needs frequent and accurate surveillance. However, the radar backscattering mechanisms of sediments and habitats are not fully understood. In this chapter, we demonstrated the influence of environmental conditions on the radar return of intertidal sediments and habitats, and further proposed new indicators for bivalve (oysters and blue mussels) beds, derived from dual-polarization TerraSAR-X, Radarsat-2, and ALOS-2 images of the German Wadden Sea. Our analyses are based on the Kennaugh element framework, whose elements are used to gain information on the total intensity at both co-polarizations and on the relative strength of even- and odd-bounce backscattering. Results show that continuous bivalve bed monitoring is possible using dual-polarization SAR acquisitions at all radar wavelengths. In addition, the actual water level, seasonal change, and local wind speed change the strength of the radar return, but also the backscattering mechanism.
