Maritime radar image may be a basis for a perspective ship position fixing system. Images obtained from navigational radars possess usually great amount of information. Using all of these information is usually practically impossible. It is necessary to compress information imbedded in each image to the size acceptable from the practical point of view. Such an effect may be obtained by application of feature extraction methods. This article presents one of such methods that is based on capabilities of modified self-organizing Kohone nneural network.