Characterization of seasonal backscatter change in subarctic wetlands and river ice breakup using Radarsat data

• Main Author: Murphy, Marley A.
• Other Authors: Martini, I.P.
• Format: Thesis
• Language: English
• Published: University of Guelph 1998
• Subjects: Radarsat data; seasonal backscatter change; subarctic wetlands; river ice breakup; environmental change; Hudson Bay; Subarctic
• Online Access: https://hdl.handle.net/10214/22328

The first objective of this research was to describe the backscatter response of Radarsat images to seasonal changes in the Hudson Bay Lowland. The second objective was to evaluate the potential of Radarsat images for predicting river ice cover breakup. Six Standard Mode images from spring, summer and fall, 1996 were used for the first objective. The backscatter response from numerous land covers was assessed and plotted over time. Environmental changes influenced backscatter more than incidence angle. Backscatter was low in spring due to the wet snow cover. Backscatter increased to a June peak because of the disappearance of snow and the increasing moisture content of vegetation. A decline into August was tied to declining amounts of water in vegetation and surface layers and a further backscatter decline into November was tied to deposition of new wet snow. Spring was found to be the best time of year for distinguishing between the land covers. Five Fine Mode images were used for the second objective. Three were pre-breakup and two were post-breakup. The images show many features indicative of approaching breakup including cracks, shear zones and texture changes from consistently mottled to distinctly patchy with circular, transverse and longitudinal bright features. Ice backscatter declined 2 to 4 dB from three weeks prior to just before breakup.