The optical arrangement of the ISAMS telescope and a typical channel are shown and some theoretical aspects of the optical design and the constraints on it are described. Data is then given on the predicted image resolution allowing for residual geometrical aberrations, diffraction and a manufacturing/assemblv error budget.
Peter F. Gray, Peter F. Gray,
"Design and Performance of the Optical Systems of ISAMS", Proc. SPIE 0589, Instrumentation for Optical Remote Sensing from Space, (1 May 1986); doi: 10.1117/12.951919; https://doi.org/10.1117/12.951919