The weight of traditional space optical imaging systems often increases nearly cubically with the increase in aperture size. To overcome this limitation, this study proposes the use of a lightweight harmonic diffractive optical imaging system combined with deep denoiser prior image restoration, to achieve high-resolution, lightweight remote sensing. This research first designed a novel 150-order harmonic diffractive optical element (H-DOE) featuring a 40-mm aperture size and a 320-mm focal length, which is equipped with seven annular zones covering a broad spectral band (500–800 nm). Its slim structure significantly reduces weight and volume, thereby lowering its launch costs. Furthermore, to address the blurring issues encountered in H-DOE imaging tasks and attain enhanced image resolution, this study incorporates an advanced image restoration technique. This technique employs a deep denoiser as a prior module, which is embedded into a model-based image restoration optimization framework. The newly trained deep denoiser utilizes a U-Net architecture integrating a transformer and residual structures and is adept at handling complex noise during the optical imaging process. The experimental results demonstrate that the performance of the proposed image restoration strategy based on a deep denoiser surpasses that of the existing technologies, elevating the resolvable frequency of the modulation transfer function (MTF) of an H-DOE imaging system from 40.58 to 98.55 lp/mm, an enhancement of 142.9%. This significant image quality improvement showcases its vast potential for use in future high-resolution, lightweight remote sensing applications.

中文翻译：

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通过谐波衍射光学成像系统和深度降噪器先验图像恢复实现高分辨率、轻量级遥感

传统空间光学成像系统的重量往往随着孔径尺寸的增加而增加近立方体。为了克服这一限制，本研究提出使用轻量级谐波衍射光学成像系统与深度降噪器先验图像恢复相结合，以实现高分辨率、轻量级遥感。该研究首先设计了一种新颖的150阶谐波衍射光学元件（H-DOE），其孔径尺寸为40毫米，焦距为320毫米，配备七个环形区域，覆盖宽光谱带（500-800 nm） ）。其纤薄的结构显着减轻了重量和体积，从而降低了发射成本。此外，为了解决 H-DOE 成像任务中遇到的模糊问题并获得增强的图像分辨率，本研究采用了先进的图像恢复技术。该技术采用深度降噪器作为先验模块，嵌入到基于模型的图像恢复优化框架中。新训练的深度降噪器采用集成变压器和残差结构的 U-Net 架构，擅长处理光学成像过程中的复杂噪声。实验结果表明，所提出的基于深度降噪器的图像恢复策略的性能超越了现有技术，将H-DOE成像系统的调制传递函数（MTF）的可分辨频率从40.58 lp/提高到98.55 lp/毫米，增强了142.9%。这一显着的图像质量改进展示了其在未来高分辨率、轻型遥感应用中的巨大潜力。