In the next step, objects are reallocated among the classes according to the relative similarity between objects and clusters based on distance analysis (e.g., Euclidian, diagonal, or Mahalanobis). Reallocation continues by iteration until a stable result is reached, in which similar objects with similar reflectance (or backscatter) characteristics are grouped together in each cluster. The advantage of k-means clustering, as well as other unsupervised methods is that they require no prior training data. Therefore, it is suitable for application to remotely sensed data for remote regions, such as high northern latitudes, where collection of training samples is difficult due to accessibility. In the first stage of the ice mapping algorithm, the fuzzy k-means was used on the backscatter-filtered images to create 10 classes. We examined a different number of backscatter classes as inputs in the classifier to select the optimal number of classes with respect to the separation of ice classes with slight differences in backscatter values, such as open water and thermal ice, juxtaposed ice and consolidated ice.