Annotation: Interacting between Geographic Information System (GIS) database and an image generated by the maritime radar sensor is a challenging task. In this paper two methods of possible real-time interaction between a radar signal and GIS will be described. Marine radar sensor can be placed on the moving platform, such as an object floating on the sea or can be positioned on the land for the coastal surveillance. The result of the radar sensor work is a bitmap produced by the original DSP based radar processor. Both mentioned methods could be considered as intelligent filters. One-method implements the filter like a surface mask based on GIS data, which splits raw radar signal in two categories (from land or from sea). Another method is focused on classifying detections, which are the results of the point-like detector. Commercial PC-based equipment is used. Both methods are implemented in a real system and can be used while the radar is operating.