Abstract
We propose new indicators for bivalve (oyster and mussel) beds on exposed intertidal flats, derived from dual-copolarization (HH + VV) TerraSAR-X, Radarsat-2, and ALOS-2 images of the German North Sea coast. Our analyses are based upon the Kennaugh element framework, and we show that different targets on exposed intertidal flats exhibit different radar backscattering characteristics, which manifest in different magnitudes of the Kennaugh elements. Namely, the inter-channel correlation’s real (K3) and imaginary (K7) part can be used to distinguish bivalve beds from surrounding sandy sediments, and together with the polarimetric coefficient (i.e., the normalized differential polarization ratio, K0/K4) they can be used as indicators for bivalve beds using multi-frequency dual-copolarization SAR data. Our results show that continuous bivalve bed monitoring is possible using dual-copolarimetric SAR acquisitions at all radar wavelengths.
Highlights
Intertidal flats are coastal areas between the land and the open sea that are at risk due to climate change, sea level rise, marine pollution, and invasive species [1–3]
We have introduced new polarimetric Synthetic Aperture Radar (SAR) indicators for bivalve beds on exposed intertidal flats that are based on dual-copol SAR data
The proposed indicators for bivalve beds consist of the normalized real (K3) and imaginary (K7) parts of inter-channel correlations, as well as on the polarization coefficient, i.e., the normalized differential polarization ratio, PC = K4/K0
Summary
Intertidal flats are coastal areas between the land and the open sea that are at risk due to climate change, sea level rise, marine pollution, and invasive species [1–3]. Further analyses of indicators based on L-band data are rare, and the present paper is to propose polarimetric SAR indicators for the detection of bivalve beds that work at all wavelengths. Further research is needed on the capabilities of existing or newly acquired dual-copolarization (dual-copol; HH + VV) SAR data [23] for monitoring intertidal flats, especially for the detection and classification of sediments and bivalve beds. We follow on those works using, among others, TerraSAR-X (TSX), Radarsat-2 (RS2), and ALOS-2 (AL2) data, with the specific aim to propose indicators for bivalve beds that were derived from dual-copol SAR data acquired at all wavelengths (X-, C-, and L-band). It is difficult to infer the spatial extent of bivalve beds using intensity channels This motivated us to use polarRiemmoetetrSiecnsi.n20f1o7r,m9, 1a0t4i7on available at all wavelengths (X-, C-, and L-band). Effectiveness in detecting bivalve beds using X-band data as previous works, and using data at longer radar wavelengths (C- and L-band)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
