Patent ID: 8380374

Claim:
A method for navigating an undersea vehicle ( 12 ), having navigation sensors ( 17 ) for measuring and continuously outputting data of the absolute speed of the undersea vehicle, a Doppler log ( 14 ) for measuring the relative speed of the undersea vehicle in successive measuring operations, and a navigation filter ( 18 ) for calculating navigation data relating to the position, attitude and absolute vehicle speed of the undersea vehicle ( 12 ) using data from navigation sensors ( 17 ) and the measured relative speed values from the Doppler log ( 14 ), said method comprising: subdividing the water area ( 10 ) through which the undersea vehicle ( 12 ) travels into regions having a finite dimension (d) at least in the vertically oriented z axis of a Cartesian coordinate system ( 11 ); determining currents in the water area inside the regions and storing determined currents as region-specific currents ( 1 s), at least during the submerging and/or surfacing phase of the undersea vehicle ( 12 ), wherein said region specific currents ( 1 s) are determined from the relative vehicle speeds (w m n ) measured by the Doppler log ( 14 ) in successive measuring operations and the absolute vehicle speeds (v F (t n )) continuously output by the navigation filter ( 17 ); inputting said stored region-specific currents ( l s) to the navigation filter ( 18 ) dependent upon the region through which the undersea vehicle ( 12 ) is respectively instantaneously traveling; and calculating said navigation data.