| 摘要 |
PURPOSE:To increase the accuracy of a sonar with respect to a signal frequency, an azimuth and an S/N ratio, and to make the adjusting of a sonar easily, by using a digitally generated sonar inspecting false signal. CONSTITUTION:An output from a shifting register 11 in M system is applied to a buffer register 15. The register 15 is adapted to generate a value of each of three samples in the M system owing to the shift locking of an output from a product gate 14, and its repeated freaquency becomes 1/3 of that of a clock frequency at a terminal 26. When a clock frequency is set to a level higher than that of an acoustic frequency of a sonar with a band of each BPF set equal to the acoustic frequency, a false having amplitude information can be obtained. An output from a ternary counter 13 is subjected to frequency divider 17, level-shifted 18 and frequency- divided 19 and then, applied through a byffer inverter 20 to resistor networks 21-23. Outputs from the BPF's 16 are added 24 to outputs from the resistor networks 21-23, and outputs from 24 are applied to terminals 37-39 corresponding to directional channels for wave receivers. |
