啁啾调幅激光强度关联成像雷达研究

Laser intensity correlated imaging is a brand-new staring imaging system, and is provided with super-resolution, high detection sensitivity, high image acquisition efficiency, and the capacity of improving the effect of atmospheric disturbance on imaging quality to a certain extent. In order to solve the bottleneck problems of pulse laser intensity correlated imaging radar, such as the mutual interaction between range resolution and single pulse laser energy, the contradiction between imaging field of view and the brightness of background light, and the inter-coupling between static target and moving target return signals, this project arms at introducing the chirped amplitude modulation technology into laser intensity correlated imaging, and developing a new imaging radar, which is called chirped-amplitude modulated laser intensity correlated imaging radar. This new imaging radar is based on the physical principle of the coherence theory of electromagnetic field and the information theory of compressed sensing theory, and fully employs the property of coherent detection and pulse compression. Through the sufficient research on the imaging mechanism, imaging features, and image reconstruction algorithms, a scheme of chirped-amplitude modulated laser intensity correlated imaging for remote sensing should be proposed. In addition, we carry out the systematic numerical simulation analysis of the scheme and perform the laboratorial principle experimental demonstration. This research not only provides a feasible technical approach for the development of a new generation of high resolution optical remote sensing imaging mechanism, but also establishes favorable theoretical basis and technical support for expanding the technology to other application fields.

激光强度关联成像属于一种全新的凝视成像体制，具备超分辨、高探测灵敏度、高图像获取效率以及一定程度上改善大气干扰对成像质量影响的能力。为了解决窄脉冲激光强度关联成像雷达所碰到的距离分辨率与激光单脉冲能量相互制约、成像视场与背景光亮度相互矛盾以及静止目标与动目标回波信号相互耦合等瓶颈问题，本项目旨在将啁啾调幅技术引入激光强度关联成像领域，发展一种以电磁场相干性理论为物理基础、压缩感知理论为信息论基础、相干探测和脉冲压缩为技术途径的全新成像雷达，称为啁啾调幅激光强度关联成像雷达。通过对该成像雷达的机理、成像特性以及图像重建算法研究，优化设计出一套可用于遥感探测的啁啾调幅激光强度关联成像方案，开展全链路的数值模拟分析并完成实验室的原理验证实验。这项研究不仅为我国发展全新一代高分辨光学遥感成像体制提供了一种可行的技术途径，而且也为该技术拓展到其他应用领域奠定了良好的理论基础和技术支撑。

激光关联成像属于一种全新的凝视成像体制，具备超分辨、高探测灵敏度、高图像获取效率以及一定程度上改善大气干扰对成像质量影响的能力。为了解决窄脉冲激光关联成像雷达所碰到的距离分辨率与激光单脉冲能量相互制约、成像视场与背景光亮度相互矛盾以及传统激光雷达静止目标与动目标回波信号相互耦合等瓶颈问题，本项目将啁啾调幅、脉冲压缩和激光关联成像技术结合起来，建立了包含啁啾调幅方式、随机光场的产生、光场传输、辐照光场与目标相互作用、相干探测、信号分析和处理等过程的啁啾调幅激光关联成像雷达物理和数学模型，确定了啁啾调幅激光关联成像雷达的成像条件以及空间分辨率、测距分辨率和测速分辨率的限制参量；给出了脉冲式直接探测体制、啁啾调幅非相干外差探测体制以及啁啾调幅相干探测体制下的激光关联成像信噪比的定量描述。优化并设计出一套可用于遥感探测的啁啾调幅激光关联成像雷达方案，开发了全链路数值模拟程序、距离-速度信息解耦方法、标量矩阵结构化关联成像和结构压缩感知三维成像等图像重建算法，数值模拟分析并厘清了光源性质、环境、目标特性、系统参数等因素对该成像雷达成像质量的影响。搭建了一套啁啾调幅激光关联成像雷达原理验证实验平台，实现了赝热光源的预置以及背景光的定量模拟控制等功能，演示了啁啾调幅激光关联成像雷达具备测距、测速、成像以及抗强背景光干扰的能力，验证了理论分析和数值模拟结果的正确性。此外，梳理出高增益平衡探测技术和单光子水平下的相干探测机理是下一步重点攻关方向，本项目的研究成果为后续样机研制提供了良好的技术支撑，有望在要地防御、战场态势感知、水下目标探测与识别等领域率先得到应用。