A technique for the identification and analysis of icebergs in synthetic aperture radar images of Antarctica

This paper describes an image analysis technique developed to identify iceb ergs depicted in synthetic aperture radar images of Antarctica and to deter mine the outlines of these icebergs. The technique uses a pixel bonding pro cess to delineate the edges of the icebergs. It then separates them from th e background water and sea ice by an edge-guided image segmentation process . Characteristics such as centroid position and iceberg area were calculate d for each iceberg segment and placed in a file for input to appropriate st atistical data analysis software. The technique has been tested on three ER S-1 SAR sub-images in which it succeeded in identifying virtually all segme nts containing icebergs of size six pixels or larger. The images were first passed through an averaging filter to reduce speckle. This process produce d a pixel size of 100 m x 100 m. As implemented, the technique overestimate s iceberg areas by about 20% on average and the detection rate falls off ra pidly for icebergs less than six pixels in size. Performance in these areas is expected to improve when additional stages, based on a more detailed an alysis of pixel intensity, are implemented.