Improving Broadband Acoustic Doppler Current Profiler with Orthogonal Coprime Pulse Pairs and Robust Chinese Remainder Theorem

Chi, Cheng; Vishnu, Hari; Beng, Koay Teong

doi:10.1109/oceanskobe.2018.8559092

Cited by 5 publications

(4 citation statements)

References 12 publications

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“…An orthogonal coprime signal is designed in [8]; the integer n can be obtained by robust CRT. C. Chi [20] proposed an unwrapping combined signal that contains three pulses y 0 , y 1 , and y 2 , where the time delay between pulses y 0 and y 1 is τ 1 , and the one between pulses y 1 and y 2 is τ 2 . Phase wrapping can be eliminated or weakened when τ 1 , τ 2 satisfies Equation (15).…”

Section: Orthogonal Combined Signalmentioning

confidence: 99%

“…Comparing with the combined signal [19], the orthogonal combined signal has higher accuracy in current velocity measurement. Besides, comparing with orthogonal coprime signal [8,20], orthogonal combined signal omits the steps of designing the coprime length of signal and resolving the velocity ambiguity, which can reduce the amount of computation. The proposed signal is easier to design than orthogonal coprime signals and theoretically has higher precision.…”

Section: Echo Signal Processingmentioning

confidence: 99%

“…The sound speed in water is set to 1500 m/s. The Doppler frequency shift is 2400 Hz, and the real current velocity is 3 m/s [8,19,20]. The transducer is oriented vertically downward, thus the multipath problem can be ignored.…”

Section: Design Example Of the Orthogonal Combined Signalsmentioning

confidence: 99%

“…In recent years, N. Han [19] designed a combined signal for solving the ambiguity in current velocity measurement, discussed the design methods based on time delay and frequency, and improved the measurement accuracy. In addition, Chi Cheng [8,20] proposed an orthogonal coprime signal, which is composed of two sub-signals with different frequencies and the signal length is prime to each other. Then, the robust Chinese remainder theorem (CRT) was used to relax the limit of the ambiguity velocity of conventional BBADCPs, while the complexity also increased.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Using Orthogonal Combined Signals in Broadband ADCP for Improving Velocity Measurement

Lin¹,

Yuan²,

Cheng³

2020

JMSE

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Broadband Acoustic Doppler Current Profiler (BBADCP) is a widely used technology in velocity measurements. To adapt to the varied water environment and different measurement requirements, flexible tuning of transmitted signal parameters will improve the feasibility and accuracy of velocity measurement. Compared with the conventional signal, the orthogonal combined signal designed in this paper can generate a wealth of signal combination examples and improve the accuracy of the velocity measurement under the same conditions. The proposed orthogonal combined signal consists of two orthogonal sub-signals with a symmetrical spectrum. Each is designed based on time delay to eliminate or weaken the current velocity ambiguity. Then, the processing method of the received signal when the pulse signals are the same or different coded signal is discussed. The numerical simulation results show that, when using the proposed method, the standard deviation of the estimated current velocity has different degrees of reduction at different current velocities. Our simulation also shows that, compared to the convention method, the proposed method can improve the SNR by 10 dB. This can help significantly increase the scope of the configuration.

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Section: Orthogonal Combined Signalmentioning

confidence: 99%