Navigational method and related equipment - uses sine-cosine potentiometer and makes incremental positional coordinate changes according to mathematical formulae

摘要

The method of position determination involves making constant increments dx, dy in the known coordinates X deg. and Y deg. of latitude and longitude, where dx=Vr cos Cr/dt and dy= Vr sin Cr/dt where Vr is the actual velocity of the moving vehicle Cr is the true heading, and dt is the time interval between two successive increments. The instrument for putting this technique into practise includes a sine-cosine potentiometer (O) supplied by voltages - Va, + Va which prepresent the apparent velocity. The potentiometer provides the components Vr cos Cr and Vr sin Cr. The actual velocity Vr is determined from the apparent velocity (Va) and the drift (d) while the true heading Cr is determined from the magnetic heading (Cm) and the declination (D).