Yu Jing, Li Yaan
School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China.
Sensors (Basel). 2016 Jun 30;16(7):1017. doi: 10.3390/s16071017.
Motion parameter estimation of a ground moving target is an important issue in synthetic aperture radar ground moving target indication (SAR-GMTI) which has significant applications for civilian and military. The SAR image of a moving target may be displaced and defocused due to the radial and along-track velocity components, respectively. The sharpness cost function presents a measure of the degree of focus of the image. In this work, a new ground moving target parameter estimation algorithm based on the sharpness optimization criterion is proposed. The relationships between the quadratic phase errors and the target's velocity components are derived. Using two-dimensional searching of the sharpness cost function, we can obtain the velocity components of the target and the focused target image simultaneously. The proposed moving target parameter estimation method and image sharpness metrics are analyzed in detail. Finally, numerical results illustrate the effective and superior velocity estimation performance of the proposed method when compared to existing algorithms.
地面移动目标的运动参数估计是合成孔径雷达地面移动目标指示（SAR-GMTI）中的一个重要问题，在民用和军事领域都有重要应用。移动目标的SAR图像可能会分别由于径向和沿航迹速度分量而发生位移和散焦。清晰度代价函数表示图像的聚焦程度。在这项工作中，提出了一种基于清晰度优化准则的新型地面移动目标参数估计算法。推导了二次相位误差与目标速度分量之间的关系。通过对清晰度代价函数进行二维搜索，我们可以同时获得目标的速度分量和聚焦的目标图像。详细分析了所提出的移动目标参数估计方法和图像清晰度度量。最后，数值结果表明，与现有算法相比，所提方法具有有效且优越的速度估计性能。
