ECHO SOUNDING APPARATUS AND ECHO SOUNDING METHOD

摘要

This echo sounding device is installed in a moving body, is for sounding an underwater object of measurement, and is provided with: a transmission signal formation unit having a pseudo-noise-sequence generation circuit for generating a pseudo-noise-sequence signal and a modulation circuit for forming a transmission signal by modulating a carrier signal using the pseudo-noise-sequence signal at a transmission timing; a transmission signal formation unit for forming a transmission signal using a pseudo-noise-sequence signal; a transmission unit for transmitting each transmission signal into the water as ultrasound; a reception unit for receiving a reception signal including a true echo, a transmission signal ghost, and a reception signal ghost; a correlator for using the pseudo-noise-sequence signal to carry out correlation processing on the reception signal and thereby measuring the distance to the object of measurement on the basis of the time difference between each transmission signal and the true echo; and a ghost removal circuit for removing the transmission signal ghost and/or reception signal ghost. The transmission signal period is made to be less than or equal to 2D/Vu, where Vu is the speed of sound in water and D is the distance to the object of measurement.