In the second stage of ice mapping, the fuzzy k-means classifier was applied to the texture-analyzed images to identify six classes of ice cover types. Only pixels (classes) within the mask from class #1, the first stage of backscatter-based classification, were extracted. These classes were then reclassified to create open water and thermal ice layers. Subsequently, three classes of thermal, juxtaposed and consolidated ice from the first classifying step were mosaicked with two classes of open water and thermal ice from the second step, creating the final ice cover map for the Slave River. Only those imagery information were extracted that coincided with the polygon areas of the river sections which are available from the CanVec database at Natural Resources Canada. Additionally, both co- (HH) and cross- (HV) polarizations were used in the backscatter-based classification of filtered images, while the texture-based classification was used with a single co-polarization (HH) backscatter. The mapping algorithm was primarily developed based on the ice cover conditions on the 21 November 2013 RADARSAT-2 image and then applied to all other images from both studied winters (Table 1). In order to compare the thresholds of backscatter values corresponding to different ice types, the backscatter samples (in dB unit) of each ice type were also extracted
In the second stage of ice mapping, the fuzzy k-means classifier was applied to the texture-analyzed images to identify six classes of ice cover types. Only pixels (classes) within the mask from class #1, the first stage of backscatter-based classification, were extracted. These classes were then reclassified to create open water and thermal ice layers. Subsequently, three classes of thermal, juxtaposed and consolidated ice from the first classifying step were mosaicked with two classes of open water and thermal ice from the second step, creating the final ice cover map for the Slave River. Only those imagery information were extracted that coincided with the polygon areas of the river sections which are available from the CanVec database at Natural Resources Canada. Additionally, both co- (HH) and cross- (HV) polarizations were used in the backscatter-based classification of filtered images, while the texture-based classification was used with a single co-polarization (HH) backscatter. The mapping algorithm was primarily developed based on the ice cover conditions on the 21 November 2013 RADARSAT-2 image and then applied to all other images from both studied winters (Table 1). In order to compare the thresholds of backscatter values corresponding to different ice types, the backscatter samples (in dB unit) of each ice type were also extracted
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