Focal plane arrays (FPA) have eliminated bulky scanning mechanisms. While it is now possible to build more compact and lighter thermal imaging systems, the demand on the performance of the imaging objective has increased. To discuss these higher demands, and to provide some guidance in how to deal with them, is the purpose of this paper.
Max J. Riedl, Max J. Riedl,
"Comments and guidelines for selecting IR objectives for focal plane arrays", Proc. SPIE 1970, Systems-Oriented Optical Design, (10 August 1993); doi: 10.1117/12.155819; https://doi.org/10.1117/12.155819