| 摘要 |
The present invention relates to an echo sounding system which operates simultaneously at a plurality of ultrasonic frequencies for the purpose of investigating sediments on the seabed. Through automatic gain regulation, averaging over the last soundings and a window electronic system for suppressing unwanted echoes in the water, the highest frequency (f1) is set up on the seabed upper edge. The other echo sounding electronic systems with the falling ultrasonic frequencies (f2, f3,..., fn) are identical in principal to f1 in construction. Starting from the physical fact that a sound signal penetrates further into the seabed the lower the frequency, the window electronic systems of f2, f3,..., fn are each driven by the echo of the next higher sound frequency f1, f2,..., fn-1. This results in echo pulses which are separate from one another, ordered according to frequency, and suitable for digitisation and relay to an EDP system.
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