This letter considers the design of a two-stage direction of arrival (DOA) scheme for radar systems. Precisely, at the first stage a sparse recovery approach is used to obtain both DOA and complex amplitude estimates of the incoming signal. Since the DOA is evaluated on a predefined grid of bins sampling the antenna azimuth mainbeam, at the second stage, a closed-form complex-valued parabolic interpolation is performed to refine it. By doing so, the angle accuracy is improved, but at the same time maintaining fixed the overall computational complexity. Numerical results show the enhancement provided by the proposed procedure to the initial sparse recovery method.

中文翻译：

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通过稀疏恢复信号的复杂抛物线插值进行DOA细化

这封信考虑了雷达系统的两阶段到达方向（DOA）方案的设计。精确地，在第一阶段，稀疏恢复方法用于获得DOA和输入信号的复振幅估计。由于在第二阶段对DOA是在对天线方位角主波束采样的预定箱格网格上进行评估的，因此将执行封闭形式的复值抛物线插值法对其进行精化。这样，可以提高角度精度，但同时保持固定的整体计算复杂性。数值结果表明，所提出的程序对初始稀疏恢复方法提供了增强。