Accurate deduction of infrared imaging features of subpixel targets based on the conversion of radiation fields of measured area targets.

The accurate generation of infrared (IR) imaging features of subpixel targets plays a very important role in the demonstration, verification, and optimization of system design schemes as well as in research into detection algorithms for small targets in the development of remote IR early warning systems. Based on the generation mechanism of target full-link IR imaging features, this study theoretically considers target radiation characteristics, the working environment, and the spatial response and energy-conversion characteristics of IR sensors, and an accurate deduction model of IR imaging features of subpixel targets is proposed and established. First, the surface-radiation field distribution of the target and background are inverted based on the measured data and the model of radiation calibration; then, the accurate simulation of IR imaging features of subpixel targets is realized by considering the geometric transformation of the spatial imaging, the aperiodic transfer function, scale registration of spatial sampling, and radiation coupling. Finally, the accuracy of the proposed model is verified by using the outfield experiment data. The experimental results show that the IR imaging-diffusion features of subpixel targets with different duty cycles are in good agreement with the prediction results of the model. The results obtained provide data support for the demonstration, verification, and optimization of the system design scheme, as well as for research into detection algorithms of small targets in the development of remote IR early warning systems.