Evaluation of discrete sampling on thermal imaging systems

Based on the aliasing theory of focal plane array (FPA) thermal imaging systems, aliasing as noise (AAN) method and under-sampling system evaluation model based on information theory (EMIT) were analyzed. The aliasing was treated as one kind of noise and introduced into minimum resolvable temperature difference (MRTD) model, and the integral expressing of aliasing signal (IAS) method was proposed to evaluate the impact of aliasing on the performance of thermal imaging systems. IAS method was proved to be able to describe the impact of aliasing grade on the system performance effectively. The three MRTD models with different aliasing evaluation methods were researched contrastively by MRTD test experiment and target detection probability experiment. The MRTD model with IAS method was proved to evaluate the performance of under-sampling thermal imaging systems effectively, and could be used in the performance prediction of thermal imaging systems. In the future, the precision of IAS method will be researched further.