喷气发动机红外辐射成像测试、处理与评估

航空喷气发动机的红外辐射特性是对发动机进行隐身设计与反隐身探测的重要依据。首先，针对发动机高温部件及燃气温度范围宽、梯度大而超出红外热像仪响应范围的问题，提出了多积分时间组合测试方法，实现了不失真测试；其次，通过多帧时间平均方法分析了各积分时间对应的测温范围，并采用逐像素辐亮度值替代方法，获得了代表发动机全部辐射信息的合成图像；最后，根据合成图像计算了发动机红外辐射强度，并与相同测点的红外光谱辐射仪测试结果进行对比，最大误差不超过10%。结果表明:基于红外热像仪的多积分时间组合测试方法及其数据处理方法是合理有效的。

IR radiation imaging test,process and evaluation of jet aeroengine

The infrared(IR) signature is the important basis for IR stealth design and anti-stealth detection of jet aero-engine. There were three major contributions in this paper. Firstly, the jet aero-engine had a wide temperature span to be measured, which was far too large for an IR camera to cover in one snapshot. This was accomplished by using multi-integral time combined measure method, each integral time was optimized to a definite range of temperature and to make sure that the combination of all integral times seamlessly covered the entire temperature range of target. Secondly, the measured temperature range of each integral time was defined by multi-frame image time-averaging method, then a per-pixel radiance replacement and images synthesization method was proposed to form an integrated IR image. Compared with IR image of single integral time, the integrated image shows abundant target details and signature information. Finally, the distribution of IR radiant intensity was calculated, compared with IR spectroradiometer measurement at the same test-point, and error was less than 10%. The result shows that proposed methods based on IR camera are all reasonable and efficient.