复杂环境下弱信号红外探测系统灵敏度需求及实现方法研究

针对真实环境条件下远距离对红外弱信号目标的成像探测任务,首先需结合中波及长波红外所选探测谱段分析各类复杂气象条件下大气传输对信号的衰减效应,提出红外系统在复杂环境下有效实现对弱信号目标远距离成像探测的灵敏度需求为系统噪声等效温差(NETD)达到5 mK；然后分析中波及长波红外系统NETD实现5 mK的技术难度,最后选用像素级数字化积分体制实现了甚高灵敏度的中波及长波红外系统并进行了NETD测试和成像探测试验。

Research on sensitivity requirement and implement method of weak signal infrared detecting system during complicated environment

For the imaging detection task of remote infrared weak signal targets under real environmental conditions,firstly,the attenuation effect of atmospheric transmission on signals under various complex meteorological conditions should be analyzed in combination with the selected detection spectrum of medium and long-wave infrared. secondly,it is proposed that the sensitivity requirement of infrared system to effectively realize remote imaging detection of weak signal targets in complex environment is that the system noise equivalent temperature difference (NETD) reaches 5mK. thirdly,after analysis on technical difficulty among possible different methods of achieving a 5mK NETD for the Mid-Wave Infrared(MWIR) and Long-Wave Infrared(LWIR) imaging system is given,the pixel-level digital integration technology is chosen for realizing the high sensitive MWIR and LWIR system. Finally,NETD test and imaging detecting test of the new system in laboratory are accomplished.