1. Integration of TerraSAR-X, RapidEye and airborne lidar for remote sensing of intertidal bedforms on the upper flats of Norderney (German Wadden Sea)
- Author
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Winny Adolph, Alexander Bartholomä, Christian Heipke, Hubert Farke, Alena Schmidt, Manfred Ehlers, and Richard Jung
- Subjects
Bedform ,010504 meteorology & atmospheric sciences ,0211 other engineering and technologies ,Intertidal zone ,02 engineering and technology ,Environmental Science (miscellaneous) ,Oceanography ,01 natural sciences ,law.invention ,Remote Sensing ,Wadden Sea ,law ,Earth and Planetary Sciences (miscellaneous) ,Radar ,RapidEye ,Digital elevation model ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Lidar ,Intertidal Bedforms ,Geotechnical Engineering and Engineering Geology ,DTM ,Remote sensing (archaeology) ,Temporal resolution ,Satellite ,Geology ,Environmental Monitoring ,TerraSAR-X - Abstract
The Wadden Sea is a large coastal transition area adjoining the southern North Sea uniting ecological key functions with an important role in coastal protection. The region is strictly protected by EU directives and national law and is a UNESCO World Heritage Site, requiring frequent quality assessments and regular monitoring. In 2014 an intertidal bedform area characterised by alternating crests and water-covered troughs on the tidal flats of the island of Norderney (German Wadden Sea sector) was chosen to test different remote sensing methods for habitat mapping: airborne lidar, satellite-based radar (TerraSAR-X) and electro-optical sensors (RapidEye). The results revealed that, although sensitive to different surface qualities, all sensors were able to image the bedforms. A digital terrain model generated from the lidar data shows crests and slopes of the bedforms with high geometric accuracy in the centimetre range, but high costs limit the operation area. TerraSAR-X data enabled identifying the positions of the bedforms reflecting the residual water in the troughs also with a high resolution of up to 1.1 m, but with larger footprints and much higher temporal availability. RapidEye data are sensitive to differences in sediment moisture employed to identify crest areas, slopes and troughs, with high spatial coverage but the lowest resolution (6.5 m). Monitoring concepts may differ in their remote sensing requirements regarding areal coverage, spatial and temporal resolution, sensitivity and geometric accuracy. Also financial budgets limit the selection of sensors. Thus, combining differing assets into an integrated concept of remote sensing contributes to solving these issues.
- Published
- 2016
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