| 摘要 |
PURPOSE:To enable identification of soil immediately after measurement without numerical calculation of a reflected wave assuming soil, by calculating the levels of the reflected waves received of two sound waves, high and low, transmitted to a water bottom to determine a relative level therebetween. CONSTITUTION:Reflected waves of burst sounds transmitted from transmitters 115 and 125 of low and high sound wave transmitting/receiving sections 11 and 12 are received separately with receivers 116 and 126 and supplied to an arithmetic processing section 13 as digital signal via amplifiers 117 and 127, band pass filters 112 and 122, rectifiers 118 and 126, low pass filters 119 and 129 A/D converters 1110 and 1210. The arithmetic processing section 13 performs a data calculation D for water depth and the thickness of layers by carrying out the setting A of a threshold from an output of the A/D converter 1110, a reading B of a time interval between rises of the respective reflected waves and a data conversion C by a sound velocity sequentially. It also accomplishes a calculation G of a relative level difference between the reflected waves from the water bottom by identifications E1 and E2 of the waveforms thereof from outputs of the A/D converters 1110 and 1210 and calculations F1 and F2 of burst range average levels and performs a processing H to identify soil from the relative level difference thus obtained. Then, the results are displayed 14. |
