Short pulse multi-frequency phase-based time delay estimation.

Area of Science:

• Signal Processing
• Acoustics
• Metrology

Background:

• Phase ambiguity is a common challenge in time delay estimation when distances exceed a full wavelength.
• Accurate distance determination is crucial in various applications, including underwater acoustics and radar.

Purpose of the Study:

• To present a novel time delay estimation approach based on phase difference detection.
• To address the phase ambiguity problem using a multiple-frequency continuous wave pulse.
• To achieve high-resolution distance measurements in challenging environments.

Main Methods:

• Utilizing a multiple-frequency short continuous wave pulse for phase difference detection.
• Leveraging the lowest frequency difference for an unambiguous range and higher frequencies for finer resolution.
• Employing phase detection via the discrete Fourier transform (DFT).

Main Results:

• Demonstrated effectiveness through theoretical and practical examples.
• Validated using underwater acoustic measurements in simulated noisy conditions.
• Achieved resolutions better than 1/50th of a wavelength, even with -5 dB additive Gaussian noise.

Conclusions:

• The presented method effectively resolves phase ambiguity in time delay estimation.
• The algorithm offers simple implementation and high accuracy, suitable for noisy environments.
• This technique provides a robust solution for precise distance determination using phase differences.