Estimation of sea state parameters based on PACSCAT motion response data

In order to improve the sailing performance of the Partially Air Cushion Support Catamaran (PACSCAT), we require real-time and accurate estimation of the sea conditions under which the ship is sailing to regulate the air cushion system pressure. In this paper, the PACSCAT's pitching test data in regular and irregular waves and the method of wave spectrum analysis are combined to study the state of the sea. Spectrum and correction analysis is performed for the pitching signal obtained under the condition of irregular head waves of the model test, using the pitching amplitude–frequency response function, to obtain the significant wave height value. The pitching amplitude–frequency response function is obtained from the ship's seakeeping test in regular waves. The pitching response inversion results of a 145 kg model under irregular waves was separated into parameters, and after comparing the inverted significant wave height to the test significant wave height, the results indicate this method can therefore be used in ship motion response signal spectrum analysis.