METHOD AND INSTRUMENT FOR DEPTH SOUNDING BY SUBMARINE REFERENCE POINT

PURPOSE:To sound the depth of the sea bottom surface with high accuracy by providing a high accuracy bathometer on a reference point where the depth of the sea bottom is measured exactly in advance, and on the other hand, mounting the same high accuracy bathometer on a rack base suspended from a supporting vessel, and calculating the suspended depth from a difference pressure portion, etc., of two sets of water depth meters. CONSTITUTION:In a depth sounding method by a submarine reference point, an ultrasonic signal is transmitted from the first transponder 2 of a rack base 10 to a second transponder 13 and from its response time, the plane position of the rack base 10 is derived. Subsequently, from the difference pressure of a seventh and a second bathometers 14, 3, the depth of the rack base 10 is derived. Next, by an inclinometer 16 and a gyro compass 15, the azimuth, the trim angle and the heel angle of the rack base 10 are corrected, the the position coordinate to an ultrasonic sonar 20 is derived three-dimensionally. Therefore, by moving the ultrasonic sonar 20 and scanning the sea bottom, the range to the sea bottom is found, and by a position measuring instrument, the place coordinate and the depth of the sea bottom surface are derived from its range bound data and the position coordinate, and for instance, a contour line diagram, a depth distribution diagram, a cross section diagram, etc., can be outputted from a personal computer.