Description
Summary:In spring 1987 in the Arctic Ocean, a submarine and two remote- sensing patrol aircraft cooperated in concurrent profiling and imaging of the upper and lower sea ice surfaces along the same track. The experiment provided opportunities for validation of airborne remote sensing systems using confirmed ice type and thickness information derived from below. Data collocation was achieved over a large area, north of Ellesmere Island for various combinations of sensors. The submarine was equipped with a narrow beam upward-looking sonar and a sidescan sonar system. A P-3A was equipped with an advanced multichannel microwave radiometer, an electrically scanning microwave radiometer, an airborne oceanographic lidar, a PRT-5 infrared radiometer, aerial cameras and video. A cessna Conquest was equipped with the Intera STAR-2 X-band SAR synthetic aperture radar. The datasets were analysed. Technical work concentrated on a detailed statistical comparison of various remotely sensed data for a 20km and a 60km section. Also 3500km of upward-looking sonar data were analysed statistically. Effort was then concentrated on a rigorous classification of the underice surface. Verification of this surface (based on submarine sonar data) was undertaken to provide an unambiguous ice type map. Results of this work indicate that analysis of X band SAR imagery is not a reliable method of deriving information about the underice surface roughness or position and orientations of ridge keels.