基于红外辐射特性的单波段红外图像被动测距

以单波段红外图像被动测距为研究背景,首先分析了凝视型红外探测系统的工作原理,将其工作过程分为入瞳前和入瞳后两个不同的阶段,其中第一阶段与目标距离相关,而第二阶段则决定于红外探测系统本身的传递函数,而后对图像像素灰度与入瞳处辐亮度之间的关系进行了表述;然后针对点目标与面目标的成像特点,分别计算了相应的目标与背景的入瞳处幅亮度差,得出:两者的红外辐射特性存在一致性.基于短时间内目标近似匀速运动的假设,推导了单波段红外图像被动测距方法.最后利用外场实测中长波红外图像对该算法进行了验证,并对测距结果和测距误差进行了详细分析.

Single-band IR passive ranging based on IR radiation characteristics

Passive ranging of single-band infrared searching and tracking (IRST) was regarded as research background. Firstly, the work principle of staring IRST system was analyzed, and the imaging process of staring infrared imaging system was divided into before and after entrance pupil two stages,the first stage was related to the target distance,and the second stage only relied on the transfer function of the IR imaging system,then the relationship between the radiance before entrance pupil and gray of image pixel was discussed;Secondly,the radiance difference of the interested target and background at entrance pupil was counted according to the imaging characteristics of the point and surface targets,and the coherence of their infrared radiation characteristics was validated. Thirdly, according to the hypothesis that the target had an even speed in short time interval, the ranging algorithm was deduced based on single-band IR image. Lastly the algorithm was validated by long-wave infrared images of outfield, and the ranging result and error were analyzed.