The main goal of tracking systems is providing the observer with a proper safety assessment, including a possibility of proper and effective trial manoeuvre planning. For the trial manoeuvre accuracy examination, some typical scenarios were simulated in a radar simulator. The research results of trial function accuracy are presented in the article.

One of the most important factors of the tracked target movement estimation accu-racy is precise information on own ship’s true course and speed. If this information is incorrect due to constant error, the computed true course and speed of the tracked target could be false. The research herein presented has dealt with the estimation accu-racy in the case when the information on true speed of own ship is false.

One consideration required in the resolution concerning radar and automatic radar plotting aid (ARPA) equipment is the possibility of an automatic drift calculation being realized in the base of fixed target tracking. This information is very important to providing safe navigation, especially in restricted areas. This paper presents an analysis of the present regulations contained in IMO resolutions and the results of an experiment conducted in the ARPA simulator. The aim of the simulations was to verify the reliability of the information presented on the ARPA display and to determine the accuracy of the automatic drift calculation implemented in the simulator.

A number of factors affect the safety of navigation, the collision of two ships being one of them. In ship encounter situations, certain principles of behaviour set forth by regulations are in force. Traditionally, a navigational situation is evaluated by identifying the closest point of approach for the passing ships and by comparing it with the assumed safe distance. Then it is necessary to use technical aids: radar and Arpa (depending on the regulations). In Arpa, navigational situation information is mainly presented in the form of vectors. The other presentation that can be used in an encounter situation is the predicted point of collision (PPC). This is the point or points toward which one’s own ship should steer at her present speed (assuming that the target does not manoeuvre) in order for a collision to occur. This paper presents original results of a study into the assessment of ship encounter situations based on PPC. The methods (analytical and graphical) of PPC as a set of circles are elaborated and an analysis of a ship encounter situation performed.

At present, providing a clear presentation of the navigational situation around a navigator’s own ship (OS) is one of the most important issues facing device manufacturers. Integration of navigational devices on the bridge has made it possible to transfer information and present it in the form chosen by the navigator screen. However, this may cause a decrease in the clarity of information and hamper its interpretation. The ability to select the best information, and that which is most needed at a given moment, depends on navigator proficiency. Vectors are still the basic form of the graphic presentation of radar-tracked object data. However, the ability to track more objects at the same time in crowded areas results in a decrease in readability and can cause errors. This article introduces the possibility of presenting information about collision danger in the form of Dangerous Courses Sectors (DCS) together with an analysis of changes in these during typical ship encounter situations. DCS are calculated on the base of Dangerous Passing Areas (DPA) as bearings on the marginal points of these areas.