不同位置强光源作用微光电视系统成像特征建模及分析

Feature Quantitative and Simulation Analysis of Low-Light-Level TV Imaging Under Highlight Disturbance at Different Locations

以强光源作用微光电视成像机理为基础,借助端到端成像建模思想,综合考虑强光源作用目标表面辐射特性及系统自动亮度控制特性,建立了不同位置强光作用后系统成像特征量化模型.以模型为基础,利用三维场景仿真平台实时计算强光源作用后地物成像灰度,实现了不同位置微光系统成像数字仿真.结合外场实验数据,通过对比实验结果与仿真结果中目标和背景灰度及目标成像对比度,对仿真模型进行了验证,结果表明:该模型与外场实验数据有较好的一致性,模型可靠性较高.最后探讨了强光作用后不同干扰因素对系统成像质量的影响,当强光源位于系统视场外时,其对目标表面辐射特性的作用是影响系统输出图像质量的主要因素;当强光源位于系统视场内时,其对系统增益的作用则成为主要因素.

Considering the interference of highlight on the radiation characteristics of the target surface and on the signal response characteristic of Low-Light-Level（LLL） TV,a feature quantitative model of LLL TV imaging under highlight disturbance was built based on the mechanism of highlight interference LLL TV imaging and the end-to-end imaging modeling idea. On the basis of the model, the simulation of the output image of LLL TV imaging system after highlight disturbed was performed by real-time calculating the imaging gray of ground objects on the three dimensional scene simulation platform. Contrasting the imaging gray of the target and its background and the imaging contrast of the target in the experimental results with that in the simulation results, the verification of the reliability of the simulation model was performed. The verification results show that the proposed model was greatly consistent with the experimental results and had high reliability. Finally, the influence of different interfering factors on the target imaging contrast was discussed, which showed that the role of highlight to the radiation characteristic of the target surface was the main factor that affecting the system imaging quality when the highlight was outside the field of view of the system, while the role of highlight to the system gain was the main factor when the highlight was in the field of view of the system.