Stem orientation measurement apparatus

摘要

An apparatus to confirm an orientation of the stem of ship by making use of a satellite included in the Global Positioning System. Radio wave signals from the satellite are received by a directional or omnidirectional antenna and the phase difference between a rotating period of said antenna and either the period of distance fluctuation, Doppler fluctuation, phase fluctuation or amplitude fluctuation is detected to obtain an orientation of the satellite which is used to obtain an accurate orientation of the stem relative to a reference direction such as due North.