基于对比度的双波段被动红外测距

Passive IR Ranging Based on Contrast in Dual-band Radiation

建立了基于双波段对比度观测的被动测距算法。应用瞬时视场概念结合美国海军红外辐射传输模型描述大气透过率造成的衰减,在3.4～5μm,8～12μm波段上得到了目标对比度与探测距离的关系式。分析表明在相邻两个探测距离上可得到4个形如lnx＋bx＋c=0的超越方程。通过求解该超越方程组,即可获得相应的目标距离。最后,给出了本文算法的理论误差曲线,分析表明该测距误差小于对比度的测量误差,适用于工作在海域的对比度受限系统对点目标的距离估计。

A passive IR ranging algorithm based on contrast in dual-band radiation was established. With the instantaneous field of view concept and the U.S. navy model combined, the relation equation of a target＇s contrast detected at 3.4～5μm and 8～12μm band via the distance from detector to the target itself is achieved. It showed that 4 transcendental functions such as lnx ＋ bx ＋ c = 0 can be obtained at two adjacent detecting distances, and then, the detecting distance can be gained by solving those 4 transcendental functions. At last, it＇s illustrated by the theoretic ranging error curve that the relative ranging error is less than the contrast-detected error, this scheme is validity to point target ranging through a contrast-limited system in maritime space.