| 摘要 |
An acoustic echo sounder, particularly used as a fish finder, includes a plurality of transducer elements 41a-41n with associated circuits 4a-4n for detecting acoustic echoes reflected from a sounding area. A receiver 1 includes a first detector 10 for detecting a target region (i.e. the direction of the target) and a second detector 20 for determining quantitative data about the target (e.g. quantity of fish in a school). The first detector 10 causes the signal intensity data to saturate to a certain extent while maintaining information on directions of the target. The second detector 20 amplifies the echo signals from the individual circuits 4a-4n while maintaining a quantitative relationship between one echo signal and another, which does not cause the signal intensity data to saturate. A data synthesiser 16 outputs data to a display 2 which presents an echo sounding picture based on the signal intensity data obtained by the first detector 10 together with the quantitative data (e.g. fish quantity) obtained by the second detector 20. |
