Evaluation of the Entrance Pupil Obscuration Ratio Influence on the Angular Resolution Characteristics of a Matrix Photodetector when Observing Point Sources

Abstract

The article examines the impact of central obscuration in an optical-electronic system's entrance pupil on the angular resolution characteristics of a matrix photo-detector during remote point source observation. The primary objective is to develop a mathematical model for analyzing signal losses caused by random point source positioning relative to photosensitive elements. A critical review of existing angular resolution evaluation methods was conducted, identifying their key advantages and limitations. The mathematical model is proposed for assessing the angular resolution characteristics of matrix photodetectors in optical-electronic systems with obscured entrance pupils. Using this model, angular resolution characteristics are calculated for systems with linear obscuration ratios ranging from η = 0--0.4 (relative units). The study derived probability distribution functions for cases where the signal portion registered by the photosensitive element nearest to the observed object's image center would be less than or equal to specified values. The comparative analysis of results across different obscuration levels was performed. The developed approach enables quantitative evaluation of obscuration effects on system threshold sensitivity through probability distribution functions for various obscuration zones. This methodology proves particularly valuable during early-stage development of optical-electronic systems

Please cite this article in English as:

Zakutaev A.A., Orekhova M.K., Mikhailov A.A., et al. Evaluation of the entrance pupil obscuration ratio influence on the angular resolution characteristics of a matrix photodetector when observing point sources. Herald of the Bauman Moscow State Technical University, Series Instrument Engineering, 2026, no. 2 (155), pp. 4--18 (in Russ.). EDN: ELJPRK

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