A ship-handling simulator: sea wave modeling

The different mathematical models are implemented for ship handling simulators. The main parts of ship handling simulator are: mathematical model of own ship (library of some ship models), mathematical model of environment (waves, wind and current), various port layouts etc. The characteristics of sea disturbances have to be defined quantitatively during the design of ship simulators (ship handling, ship navigation, marine engine simulators, etc.). The convenient data are available in the form of the energy spectral density functions (Pierson-Moskowitz, Jonswap, Voznesensky-Netsvetaeva, Darbyshire, Tabain, Davidon). Following a linear theory, using the spectral factorization techniques, the sea spectrum has been modeled by transfer function representation (colored filter). An algorithm of non-linear regression for rationalization of sea spectrum, described by the Pierson-Moskowitz expression, is given in the paper. The results of the computer simulation are presented.