The azimuth phase coding (APC) technique is known for its very low implementation complexity and its effectiveness for point and distributed ambiguities in conventional synthetic aperture radar (SAR) systems. In recent years, as an extension, the APC technique has been briefly discussed for multichannel SAR systems. However, the properties of the APC technique are no longer guaranteed in the multichannel SAR systems based on the digital beamforming (DBF) on-receive, and only a slight APC gain in the suppression of the range ambiguity can be obtained. In this article, we first provide a more thorough analysis for an APC-multichannel SAR system with respect to a uniform pulse-repetition frequency (PRF). Then, the APC/multichannel SAR system with nonuniform spatial sampling is briefly discussed, and an improved reconstruction approach based on a quadratically constrained optimization model is proposed to increase greatly the APC gain with respect to existing multichannel reconstruction algorithms. This proposed approach allows the minimization of the range ambiguity with a given azimuth-ambiguity constraint. In particular, for some specific PRFs, the proposed method permits a cancellation of the odd-order range ambiguity. Finally, simulation experiments are performed to verify the advantages and effectiveness of the proposed approach.

中文翻译：

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具有非均匀空间采样的 APC/多通道 SAR 系统的二次约束模糊度抑制算法

方位相位编码 (APC) 技术以其非常低的实现复杂度和对传统合成孔径雷达 (SAR) 系统中的点和分布式模糊度的有效性而著称。近年来，作为一种扩展，APC 技术已被简要讨论用于多通道 SAR 系统。然而，基于接收时数字波束成形（DBF）的多通道 SAR 系统不再保证 APC 技术的特性，在抑制距离模糊方面只能获得很小的 APC 增益。在本文中，我们首先针对统一脉冲重复频率 (PRF) 对 APC 多通道 SAR 系统进行更彻底的分析。然后，简要讨论了具有非均匀空间采样的 APC/多通道 SAR 系统，并提出了一种基于二次约束优化模型的改进重建方法，相对于现有的多通道重建算法，大大提高了 APC 增益。这种提议的方法允许在给定方位角模糊度约束的情况下最小化距离模糊度。特别是，对于某些特定的 PRF，所提出的方法允许消除奇数阶距离模糊。最后，通过仿真实验验证了所提出方法的优点和有效性。所提出的方法允许消除奇数阶范围模糊。最后，通过仿真实验验证了所提出方法的优点和有效性。所提出的方法允许消除奇数阶范围模糊。最后，通过仿真实验验证了所提出方法的优点和有效性。