SHIP SPEED MEASUREMENT METHOD WITH DOPPLER LOG Russian patent published in 2019 - IPC G01S15/58 

FIELD: measurement technology.

SUBSTANCE: invention relates to the field of navigation, namely to the methods and devices for measuring a ship’s absolute speed. Solved technical problem is improvement of operational characteristics of Doppler log. Technical result is achieved by using the following two technical solutions: 1) by selection of probing signal duration T_PS from minimum function

where

Δƒ – expansion of echo signal spectrum as a result of rolling; ψ′_em, ψ′_rec – rate of changing bank angle of ship during emission of probing signal and reception of echo signal, degrees/s; T_PS is duration of probing signal, s; ƒ_PS is the probing signal frequency, Hz; ƒ_ES echo signal frequency, Hz; V is ship speed, m/s; ψ_em is angle between direction of emission and direction vertically downwards, degrees; ψ_rec is angle between direction of echo signal arrival and direction vertically downwards, degrees; C_sd is sound velocity in water at receiving-emitting antenna position, m/s; 2) by radiation at one vessel speed measurement cycle N_PS tone probing signals, number of which is determined by formula , where H is depth under keel, C_sd is sound velocity in water, frequency measurement of each detected echo and averaging of measured frequencies of all detected echo signals (ill. 5).

EFFECT: high accuracy of measuring ship speed in rolling conditions.

1 cl, 5 dwg