Infrared signature measurement of targets accounting for atmospheric attenuation

Infrared radiation signature measurement of targets is one of important ways for target signature acquirement and target recognition. When measuring the infrared signature of a target in the atmosphere, molecules and aerosol particles in the atmosphere would attenuate the infrared radiation from the target, and at the same time, the air path radiation would be added to the target radiation. Therefore, in order to obtain the intrinsic infrared radiation of the target, it is necessary to perform atmospheric correction in the process of target radiation inversion. A model for target radiation measurement and inversion was established, and precision analysis on the model was given. A longwave infrared camera was used to perform infrared signature measurement experiment on an ISDC extended-area blackbody. Based on atmospheric parameters, the atmospheric transmittance and the air path radiation between the blackbody target and the camera were calculated by using the MODTRAN software, for use in atmospheric correction in the target radiation inversion process. The experimental results showed that radiation inversion precisions were about 7.3%~9.3%. Additionally, inversion precision will improve as target temperature rises.