Abstract
Exact measurement of heaving and rolling for ship is important in exact searching for the seabed patterns by a sonar. From this point of view, the authors developed before an automatic measurement system which measures the heaving and rolling of ship by using two servo-type accelerometers appropriately located on the deck. In the development, pitching was assumed to be neglected because the measurement system is usually set up on a compar-atively large ship. But, practically, there is often the case where the system is used by not so large-sized ship. This case, pitching can not be neglected and thus the effect of the pitching must be taken into account in the development of the measurement system.
The paper proposes more general measurement system of heaving and rolling which uses three servo-type accelerometers in order to be able to reflect even on the effect of the pitching.
