Motion compensation using joint-sub-band phase unwrapping for synthetic aperture sonar.

Shiping Chen,Haining Huang,Peng Wang,Jiyuan Liu,Cheng Chi,Pengfei Zhang,Yu Li

doi:10.1121/10.0009059

Shiping Chen, Haining Huang + Show 5 more

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https://doi.org/10.1121/10.0009059

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Abstract

Displaced phase center antenna (DPCA) micro-navigation has been widely applied in the motion compensation of synthetic aperture sonars (SASs). Estimating the time delay is the most important step for DPCA-based motion compensation. However, at present, the existing methods of estimating the time delay in motion compensation are not sufficiently accurate, which limits the improvement of imaging quality of SASs. This paper proposes a time delay estimation method using joint-sub-band phase unwrapping, which achieves much higher estimation accuracy than the reference method. The experimental results demonstrate that the proposed method dramatically improves the SAS imaging quality, compared to the reference method.

Highlights

Synthetic aperture sonars (SASs) coherently integrate data along a synthetic array to produce high-resolution images or terrain maps of the seafloor, which requires that the estimation of the array path be sufficiently accurate, typically to within a subwavelength.1–5 This is challenging in global positioning system (GPS) denied environments, where even highgrade navigation devices such as inertial measurement unit (IMU) and Doppler velocity log (DVL) may not yield sufficient accuracy.6,7Micro-navigation techniques provide an alternative to motion estimation and compensation
Displaced phase center antenna (DPCA) micro-navigation has been widely applied in the motion compensation of synthetic aperture sonars (SASs)
Displaced phase center antenna (DPCA), commonly referred to as redundant phase centers (RPC)8 is a widely used micro-navigation technique, which operates by forming a virtual phase center array between consecutive pings

Summary

Introduction

Synthetic aperture sonars (SASs) coherently integrate data along a synthetic array to produce high-resolution images or terrain maps of the seafloor, which requires that the estimation of the array path be sufficiently accurate, typically to within a subwavelength. This is challenging in global positioning system (GPS) denied environments, where even highgrade navigation devices such as inertial measurement unit (IMU) and Doppler velocity log (DVL) may not yield sufficient accuracy.6,7Micro-navigation techniques provide an alternative to motion estimation and compensation. Synthetic aperture sonars (SASs) coherently integrate data along a synthetic array to produce high-resolution images or terrain maps of the seafloor, which requires that the estimation of the array path be sufficiently accurate, typically to within a subwavelength.. Synthetic aperture sonars (SASs) coherently integrate data along a synthetic array to produce high-resolution images or terrain maps of the seafloor, which requires that the estimation of the array path be sufficiently accurate, typically to within a subwavelength.1–5 This is challenging in global positioning system (GPS) denied environments, where even highgrade navigation devices such as inertial measurement unit (IMU) and Doppler velocity log (DVL) may not yield sufficient accuracy.. Micro-navigation techniques provide an alternative to motion estimation and compensation. Estimating the time delay between successive pings is the most important step for DPCA-based motion compensation.. Estimating the time delay between successive pings is the most important step for DPCA-based motion compensation. In addition, the precise estimation of time delays between echoes is crucial and essential for other SAS applications, including platform localization/ navigation and interferometry techniques.

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Results

Conclusion