| 摘要 |
PROBLEM TO BE SOLVED: To provide improvement technology related to preprocessing of A/D conversion.SOLUTION: A signal amplification part 20 includes: a plurality of logarithmic amplifiers (LOG amplifiers). Each logarithmic amplifier applies amplification processing to an analog reception signal obtained from a vibrator corresponding thereto via a reception amplifier with an amplification property corresponding to a logarithmic function. Thereby, a dynamic range of the analog reception signal is compressed. An A/D conversion part 30 includes: a plurality of A/D converters. Each A/D converter applies analog/digital conversion processing to the analog reception signal after the amplification processing obtained from the logarithmic amplifier corresponding thereto to obtain a digital reception signal. A control part 60 determines a maximum level of an echo signal on the basis of the echo signal obtained from a phasing addition part 40, and controls the logarithmic amplifiers of the signal amplification part 20 such that each logarithmic amplifier has the amplification property corresponding to the maximum level. |
