{'fraction_non_alphanumeric': 0.027906976744186046, 'fraction_numerical': 0.0031007751937984496, 'mean_word_length': 5.8, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Choosing Optics For Infrared (IR) Imaging Systems (And For Missile-Borne Trackers)

The intent of this paper is to provide a comprehensive overview of the optical factors which affect system choice in 10μ imaging applications. Illustrative design alternatives are developed and discussed. Single element designs, refractors, reflectors, and catadiop-tric designs are described and compared. Diffraction-limited performance is explained and predictions made of real-world performance. Production tolerances, and a method for predicting degradations experienced in mass production are presented. Radiometric aspects are left for subsequent papers.