This paper proposes a method to estimate the target velocity using a combination of two hyperbolic frequency-modulated (HFM) signals. The Doppler-shifted time-delay between the two signals compared with the original time-delay is used to estimate the target velocity. One finds that a HFM with an increasing frequency sweep (positive HFM) and one with a decreasing frequency sweep (negative HFM) yield a different time. And a better Doppler estimation can be obtained by using a negative HFM signal followed by a positive HFM signal than the other way around. The method is applied to real data and performance is demonstrated via simulated data.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1121/1.4982724 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Parameter estimation of the hyperbolic frequency-modulated bat calls using hyperbolic scale transform.
J Acoust Soc Am
July 2024
Department of Early Warning Technology, Air Force Early Warning Academy, Wuhan, 430019, China.
Echolocating bats are known to vary their waveforms at the phases of searching, approaching, and capturing the prey. It is meaningful to estimate the parameters of the calls for bat species identification and the technological improvements of the synthetic systems, such as radar and sonar. The type of bat calls is species-related, and many calls can be modeled as hyperbolic frequency- modulated (HFM) signals.
View Article and Find Full Text PDFMultiuser Chirp Spread Spectrum Transmission in an Underwater Acoustic Channel Applied to an AUV Fleet.
Sensors (Basel)
March 2020
SEACom Department, L@bisen Yncréa-Ouest, 29228 Brest CEDEX 2, France.
The objective of this paper is to provide a multiuser transmission technique for underwater acoustic communication in the framework of an Autonomous Underwater Vehicle (AUV) fleet. By using a variant of a Hyperbolically Frequency-Modulated (HFM) signal, we describe a new family of transmission techniques called MultiUser Chirp Spread Spectrum (MU-CSS), which allows a very simple matched-filter-based decoding. These techniques are expected to provide good resilience against multiuser interference while keeping good robustness to Underwater Acoustic (UWA) channel impairments like Doppler shift.
View Article and Find Full Text PDFSpin Lock Adiabatic Correction (SLAC) for B-insensitive pulse design at 7T.
J Magn Reson
November 2019
Melbourne Brain Centre Imaging Unit, The University of Melbourne, Melbourne, VIC, Australia; Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC, Australia. Electronic address:
A new framework for B insensitive adiabatic pulse design is proposed, denoted Spin Lock Adiabatic Correction (SLAC), which counteracts deviations from ideal behaviour through inclusion of an additional correction component during pulse design. SLAC pulses are theoretically derived, then applied to the design of enhanced BIR-4 and hyperbolic secant pulses to demonstrate practical utility of the new pulses. At 7T, SLAC pulses are shown to improve the flip angle homogeneity compared to a standard adiabatic pulse with validation in both simulations and phantom experiments, under SAR equivalent experimental conditions.
View Article and Find Full Text PDFAn Improved Velocity Estimation Method for Wideband Multi-Highlight Target Echoes in Active Sonar Systems.
Sensors (Basel)
August 2018
Key Laboratory of Underwater Acoustic Signal Processing of Ministry of Education, Southeast University, Nanjing 210096, China.
In active sonar systems, the target echoes are usually equivalent to a superposition of the Doppler-scaled reflections from multiple highlights. The reflections overlap with each other both in the time and frequency domain, which results in a decreased velocity estimation performance. Recently, the hyperbolic-frequency modulated signal has been widely employed in sonar systems for moving targets due to its Doppler tolerance, while the precise velocity estimation becomes a great challenge under such conditions.
View Article and Find Full Text PDFA method of velocity estimation using composite hyperbolic frequency-modulated signals in active sonar.
J Acoust Soc Am
May 2017
Science and Technology on Sonar Laboratory, Hangzhou Applied Acoustics Research Institute, Number 715 Pingfeng Road, Hangzhou, 310023, China.
This paper proposes a method to estimate the target velocity using a combination of two hyperbolic frequency-modulated (HFM) signals. The Doppler-shifted time-delay between the two signals compared with the original time-delay is used to estimate the target velocity. One finds that a HFM with an increasing frequency sweep (positive HFM) and one with a decreasing frequency sweep (negative HFM) yield a different time.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!