Method of determining depth values for the surface profile of the bottom of a body of water

Abstract

A method of determining depth values for the bottom profile of a body of water from pulse transit times and sounding directions by means of a fan beam echo sounder that measures transversely to the longitudinal axis of the ship, whose transducer array is installed at an angle obliquely to the vertical elevation axis of the ship and wherein the pulse transit times are measured and stored in association with the sounding directions, with the sounding directions .alpha..sub.oi being calculated from data furnished by the transducer array and by the transducer signals as well as by means of a predeterminable sound velocity c.sub.o at the surface of the transducer array. For each transducer array, selected depth values are determined in the vertical sounding direction .alpha..sub.ov and in a sounding direction .alpha..sub.On that is normal to the plane of the transducer array. Estimated depth values for an estimated profile are determined for all remaining sounding directions .alpha..sub.Oi by means of the selected depth values of the profile of the bottom of the body of water. For at least one of the remaining sounding directions, the estimated depth value is compared with the depth value determined as the depth measurement value from the measured pulse transit time and a correction factor k is determined for the sound velocity c.sub.O. The depth values for the bottom profile of the body of water are determined from the stored pulse transit times and from the sounding directions calculated for the corrected sound velocity c.sub.1.

Dependencies are inferred from the claim text.