The small imaging size of targets over long distances results in the loss of geometry and spatial features. Current methods are subject to sampling limitations and cannot accurately capture the spatial features of sub-pixel targets. This paper proposes a method to accurately locate and extract the fine spatial features of sub-pixel targets through aperture coding and micro-scanning imaging. First, the formation mechanism of imaging features for sub-pixel targets is analyzed. Second, the optical aperture is anisotropically coded in different directions to modulate the spreading spots of the target. The primary spreading direction and the center of the anisotropic spreading spots are extracted. The contour and the location of the target are determined from the spreading length and the intersections of the primary spreading directions. Then, the target is sampled by different detector units through various micro-scanning offsets. The pixel units containing different sub-pixel components of the target after offset are determined based on the location results. The fine spatial distribution of the sub-pixel target is reconstructed based on the intensity variations in the pixel units containing the target. Finally, the accuracy of the sub-pixel target fine spatial feature extraction method is validated. The results show a sub-pixel localization error of less than 0.02 and an effective improvement of the sub-pixel target spatial resolution. This paper provides significant potential for improving the ability to capture spatial features of targets over long distances.

中文翻译：

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基于孔径编码和微扫描成像机制的亚像素目标精细空间特征提取方法

长距离目标的成像尺寸较小，导致几何和空间特征的丢失。目前的方法受到采样限制，无法准确捕捉亚像素目标的空间特征。本文提出一种通过孔径编码和微扫描成像精确定位和提取亚像素目标精细空间特征的方法。首先，分析了亚像素目标成像特征的形成机制。其次，光学孔径在不同方向上进行各向异性编码，以调制目标的扩散光斑。提取主要扩散方向和各向异性扩散点的中心。目标的轮廓和位置是根据扩展长度和主要扩展方向的交点确定的。然后，通过各种微扫描偏移，由不同的探测器单元对目标进行采样。根据定位结果确定偏移后目标包含不同子像素分量的像素单元。基于包含目标的像素单元的强度变化来重建子像素目标的精细空间分布。最后验证了亚像素目标精细空间特征提取方法的准确性。结果表明，亚像素定位误差小于0.02，有效提高了亚像素目标空间分辨率。本文为提高捕获远距离目标空间特征的能力提供了巨大的潜力。