采样式成像系统中混叠影响的初步研究

Preliminary Research on the influence of Aliasing in the Sampled Imaging System

由于采样的固有局限性 ,绝大多数可见和红外的采样式成像系统都存在着不同程度的频率混叠 (或者虚假响应 )问题。伴随着对高分辨率遥感图像的追求 ,采样式成像系统中混叠对图像质量的影响程度一直是人们所关心的问题 ,并提出了不少混叠的量化及容忍程度的方法和标准。文章采用Shade提出的混叠标准 ,对当今的IKONOS、Quickbird、Pleiades等卫星上的高分辨率空间相机进行了仿真和计算 ,分析了这些采样式成像系统中频率混叠的程度 。

Because of the inherent feature of sampling, most optical and infrared sampled imaging systems suffer from different amounts of aliasing (or spurious response). With the rising demands of high resolution images, the problem that people always care about is the extent of aliasing affecting the final image quality in sampled imaging systems. Meanwhile many measures of aliasing quantification and criteria of aliasing tolerance have been proposed. In the paper, Shade's aliasing criteria is introduced. Based on it, simulation and calculation are carried out, about the payloads of high-resolution space camera on the satellites of IKONOS, Quickbird and Pleiades. Finally, the aliasing extent of these sampled imaging systems is analyzed, and the simulating results are discussed.