Determination of the precise observed ship’s position using the traffic control systems and applying the geodesic estimation methods

In the sea areas with heavy traffic, there is a great danger of collision or grounding. In order to improve maritime safety at the gulf of Gdańsk in the middle of 90s, a vessel traffic services was installed. The VTS system operators can provide navigational assistance, if the parameters of the ships movement endanger the safety of navigation. For proper functioning of the system there is a network of coastal radars stations whose signal is used to create a radar picture of the navigational situation. In the vts determination of the ship position based on radar observations may lead to large errors. The IMO organization recommends to reject and repeat measurements containing large errors. For a moving ship perform a re-measurement in the same position is not possible. This paper presents possibility of compensation the coordinates of the vessel position based on radar observations using the of M-estimation methods.