目标红外辐射特性的研究对红外探测距离的预测和评估具有重要的意义。分析了基于红外图像的面目标红外辐射特性反演方法用于反演点目标特性时的局限和不足。通过对红外图像上点目标的提取, 结合辐射基本理论, 推导了目标辐射亮度、像元数和目标整体辐射强度之间的关系, 提出了一种针对小目标态势下旋翼飞机的红外辐射特性反演算法, 并利用该算法对某型旋翼飞机的红外辐射强度进行了反演计算, 得到了不同观测角度下3~5 m波段红外辐射强度分布。结果表明, 该方法可以实现远距离小目标红外辐射强度的反演, 对于红外侦察系统的作用距离评估具有一定的意义。

The study of infrared radiation properties of military targets is important for the evaluation of IR detection range. The limitation and defect of the IR property inversion method based on infrared images when it is used to inverse the properties of point targets are analyzed. According to the principle of radiation measurement, the mathematical relationships among the radiance, pixel grey value and radiation intensity are deduced by extracting the point target in an IR image. A new algorithm for inversing the IR radiation properties of a helicopter in point target detection is proposed and is used to inverse the infrared radiation intensity of a certain military helicopter. The radiation intensity distribution of the helicopter at different observational angles in the waveband of 3 to 5 m is calculated. The results show that the algorithm can implement the inversion of IR radiation properties of small targets in far distance. It is of significance to the evaluation of infrared radiation detection range of IR reconnaissance systems.