红外搜索系统俯仰角测量的大气折射修正

Error Correction of Pitch Angle Measurement on IR Searching System

大气的非均匀分布导致光线在大气传播时产生折射现象,其传输路径变成一条曲线,影响红外搜索系统对空中目标的探测精度。要精确引导跟踪系统对目标进行锁定和瞄准,必须对目标的俯仰角度进行修正。通过研究波长、大气压强和大气温度对大气折射率的影响来定量描述大气折射率的变化规律,在大气球面分层模型中利用微分法推导测角误差,最终得出误差角度的计算方法。红外搜索系统在通过ADS-B技术进行标定之后,对高度500m的无人机和高度2km的飞机数据进行了验证,试验结果表明在低空红外探测系统中利用本方法可以有效提高测角精度。通过误差修正,提升了红外搜索系统的探测性能,使之在低空侦查、防御领域中能够发挥更为重要的作用。

Due to non-uniform distribution of the atmosphere, the light is refracted in the atmospheric propagation and become a curve. It affect on air target detection accuracy on IR searching system. To accurately guide the tracking system to lock on to and aim at the target, the target pitch angle must be corrected. By studying the influence of wavelength, atmospheric pressure and atmospheric temperature, the variation of the atmospheric refractivity is quantitatively described. The differential method is used in spherically stratified atmosphere model to derive angle measurement error, and obtain calculation of error angle. After the calibration of ADS-B, some experiments are made with the UAV（500m high） and the aircraft（2km high）. The results show that this method can improve the accuracy of angle measurement effectively. By error correction, detection performance of the IR searching system is improved and it can play a more important role in the low-level detection and defense.