The observation of the surface roughness characteristics of the Rhine plume frontal boundaries by simultaneous airborne thematic mapper and multifrequency helicopter-borne radar scatterometer

Abstract In this paper, we describe how high spatial resolution (10 m) multisensor remote sensing techniques can be used to study the surface roughness characteristics of large scale frontal boundaries (in this case associated with the Rhine Plume). The instrumentation employed in the research consisted of a Daedalus AADS 1268 Airborne Thematic Mapper (ATM) operated by the UK National Environment Council, the HELISCAT helicopter-borne multifrequency microwave scatterometer of the University of Hamburg, and research vessels (R.V.s) from the University of Wales and the Dutch Rijkswaterstaat. The data we present were gathered on 24 April 1991 when calm wind conditions developed within the test area. A sequence of thermal infrared images gathered by the ATM provides a record of the motion of a frontal boundary through this experimental region which is then used to identify the frontal signature in the HELISCAT data. ATM sunglint images show that the front is characterized by a zone of reduced surface roughnes...