Abstract:
Frequency modulation continuous wave (FMCW) laser radar (Ladar) is a new radar system suitable for long-range detection and high-resolution imaging. However, the transmit...Show MoreMetadata
Abstract:
Frequency modulation continuous wave (FMCW) laser radar (Ladar) is a new radar system suitable for long-range detection and high-resolution imaging. However, the transmitted signal inevitably suffers from nonlinear frequency modulation errors which reduce the quality of Ladar imaging. We propose a nonlinear phase estimation and compensation method based on synchrosqueezing wavelet transform (SST). We first use SST to synchrosqueeze the dechirp signal containing a reference range in time-frequency domain and obtain the time-frequency information of the reference dechirp signal. As SST could aggregate the time-frequency distribution of noise, the proposed method is effective even in a noisy environment. A nonlinearity model in time-frequency domain is then built to estimate the nonlinear phase of the transmitted signals by using the time-frequency information of the reference dechirp signal. For the case of long-range detection, we adopt a residual video phase filtering to convert the nonlinear phase of the dechirp signal to range-independent phase errors. Finally, the nonlinearity of the dechirp signal is compensated using the estimated nonlinear phase of the transmitted signals. The experimental and real data tests show that the proposed method effectively improves the resolution of long-range Ladar imaging by compensating for the nonlinearity of the dechirp signal. Its advantage is the effectiveness for noisy and multicomponent FMCW Ladar signals.
Published in: IEEE Geoscience and Remote Sensing Letters ( Volume: 18, Issue: 7, July 2021)
Keywords assist with retrieval of results and provide a means to discovering other relevant content. Learn more.
- IEEE Keywords
- Index Terms
- Wavelet Transform ,
- Nonlinear Estimation ,
- Phase Compensation ,
- Frequency Modulated Continuous Wave ,
- Nonlinear Phase ,
- Nonlinear Compensation ,
- Reference Values ,
- Nonlinear Model ,
- Time Model ,
- Modulation Frequency ,
- Time Frequency ,
- Nonlinear Method ,
- Noisy Environments ,
- Real Test ,
- Noisy Signal ,
- Multicomponent Signal ,
- Imaging Results ,
- Signal Frequency ,
- Polynomial Regression ,
- Target Range ,
- Continuous Wavelet Transform ,
- Reference Signal ,
- Time-frequency Resolution ,
- Range Profile ,
- Hilbert Transform ,
- Degree Of Nonlinearity ,
- Ideal Signal ,
- Instantaneous Frequency ,
- Nonlinear Terms ,
- Signal Curve
- Author Keywords
Keywords assist with retrieval of results and provide a means to discovering other relevant content. Learn more.
- IEEE Keywords
- Index Terms
- Wavelet Transform ,
- Nonlinear Estimation ,
- Phase Compensation ,
- Frequency Modulated Continuous Wave ,
- Nonlinear Phase ,
- Nonlinear Compensation ,
- Reference Values ,
- Nonlinear Model ,
- Time Model ,
- Modulation Frequency ,
- Time Frequency ,
- Nonlinear Method ,
- Noisy Environments ,
- Real Test ,
- Noisy Signal ,
- Multicomponent Signal ,
- Imaging Results ,
- Signal Frequency ,
- Polynomial Regression ,
- Target Range ,
- Continuous Wavelet Transform ,
- Reference Signal ,
- Time-frequency Resolution ,
- Range Profile ,
- Hilbert Transform ,
- Degree Of Nonlinearity ,
- Ideal Signal ,
- Instantaneous Frequency ,
- Nonlinear Terms ,
- Signal Curve
- Author Keywords