{'fraction_non_alphanumeric': 0.022780832678711706, 'fraction_numerical': 0.003142183817753339, 'mean_word_length': 5.402010050251256, '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}}
Compact Solution for Low Earth Orbit Surveillance

Low Earth Orbit Objects (LEOs) are objects that circle our planet at a distance of less than 2000 km from the surface. Due to their small orbital radius, they move fast and are sometimes affected by atmospheric drag, meaning that their orbit will change in time. This orbit includes communication satellites, Earth observation satellites, but also space debris such as rocket bodies which will eventually reenter the atmosphere. The fast motion, the changing nature of the orbit, their sheer number, and the periodic reentry events, lead to the need of intense observation of their position. This paper presents a compact, portable system for surveillance of the LEO objects. The system is built with commercially available, low-cost items, and is capable of on-site acquisition and real time processing of images. The acquired images are processed by background subtraction, analysis of the difference between frames, extraction of elongated objects corresponding to the satellite streaks, and forming trajectories (tracklets) from consecutive detections. The emphasis on trajectories instead of individual object properties allows successful detection of faint objects, without a significant increase in false positives.