| 摘要 |
The signal appearing at the receiver input of a pulse code active sonar during a return echo period, is sampled, time compressed and stored in a memory. The time compressed sample is successive read-out of memory, with each individual "read-out" hetrodyned with a discretely different doppler compensation frequency signal. The successively processed read-outs are passed through an "on line" correlation detection device to determine presence of a correctly compensated pulse code echo.
|
