地面点源中波红外探测建模与验证研究

Modeling and Verification of Ground Point Source for Mid-Wave Infrared Detection

红外系统在大范围内对异常热源点目标的探测需要平衡像元分辨率与温度灵敏度之间的关系。在探测器规模一定时,现有星载红外载荷存在幅宽大时灵敏度不够、空间分辨率高时幅宽小的问题。针对上述问题,本文提出利用时间延时积分(time delay intergration,TDI)算法处理图像的大视场异常点热源探测初步方案,在一定条件下,达到探测所需的温度灵敏度要求时,能做到217 km×122 km的理论幅宽。同时搭建了一套高灵敏度红外成像实验系统,开展了测试与模拟探测实验,结果表明本方案在实现202 km×114 km幅宽情况下,灵敏度性能约37 m K,满足大范围异常点热源探测的要求。考虑到目标和背景的太阳光反射率等问题,实际应用时取200 m像元分辨率,对应幅宽128 km×102 km。

The detection of anomalous heat source point targets in a wide range of infrared systems requires a balance between the pixel resolution and temperature sensitivity.Given that the scale of the detector is stable,the existing space-borne infrared payloads have insufficient sensitivity when the amplitude is large and small amplitude when the spatial resolution is high.In response to these problems,in this study,we propose a preliminary plan for detecting heat sources at abnormal points in a large field of view using a time-delay integration(TDI)algorithm to process images.Under certain conditions,the temperature sensitivity requirements for detection can be satisfied and a theoretical width of 217 km×122 km can be achieved.A set of high-sensitivity infrared imaging experimental systems was built,and testing and simulation-based detection experiments were conducted.The results show that the sensitivity performance of this scheme is approximately 37 mK when a width of 202 km×114 km is realized,which fulfills the requirements for detecting a large-scale abnormal point heat source.Considering the solar reflectance of the target and background,a pixel resolution of 200 m is used in practical applications,which corresponds to a width of 128 km×102 km.