Methodology for Characterizing Night Vision Goggle Systems Using Modulation Transfer Function

Abstract

This study presents an initial step toward an objective methodology for characterizing night vision goggle (NVG) systems using the modulation transfer function. Although NVGs remain essential in operational environments, their performance has traditionally been assessed through subjective judgments made by human observers. To overcome this limitation, the proposed approach replaces the human observer – specifically the human eye and its visual acuity – with a conventional camera operating in the visible region of the electromagnetic spectrum. The methodology is fully reproducible using a standard computer monitor and an ordinary camera. A simple optical assembly was developed to couple the camera to the NVG under evaluation. The results demonstrate that the methodology can detect performance degradation introduced by the NVG, including contrast loss, increased noise, and reduced sampling efficiency. The approach also supports the selection of appropriate color-target combinations and monitor-imaging conditions for repeatable characterization. The method detected sampling-efficiency reductions from 100% (reference) to 45%, 40%, and 23% under full-moon, quarter-moon, and starlight conditions, respectively. Rather than replacing human observers, this approach should be regarded as a complementary analytical procedure.