| Autor: |
Thaddeus J. Kurpiewski, Byron W. Tietjen |
| Rok vydání: |
2008 |
| Předmět: |
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| Zdroj: |
The Journal of the Acoustical Society of America. 123:2467 |
| ISSN: |
0001-4966 |
| Popis: |
The present invention is directed to a sonar system that includes a transmitter configured to direct multi-frequency transmit signals into a propagation channel. Each multi-frequency transmit signal includes a first frequency and a second frequency. A receiver is tuned to receive multi-frequency return signals propagating in the propagation channel. Each multi-frequency return signal includes a first frequency return signal and a second frequency return signal. The first frequency return signal has a first phase and the second frequency return signal having a second phase. A signal processor is coupled to the receiver. The signal processor is configured to extract the first phase and the second phase from the multi-frequency return signal and calculate a phase difference. The phase difference is the difference between the first phase and the second phase. The phase difference corresponds to an acoustic impedance value of a material disposed in the propagation channel, and may be used to detect and classify a target of interest in background noise. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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