THE ARECIBO OBSERVATORY AS AN INSTRUMENT FOR INVESTIGATING ORBITAL DEBRIS
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Date
2021-11-22Author
Murray, James Isaiah
0000-0002-5400-0490
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In this dissertation, the Arecibo Observatory, both past and future, as an instrument for investigating orbital debris is investigated. For over three decades, models of the orbital debris environment in low Earth orbit (LEO) have been developed to assess the risk posed by orbital debris to spacecraft. While terrestrial radar measures debris 3 mm and larger and in-situ measurements provide data for debris smaller than 1 mm, no good data sources exist for debris between 1 mm and 3 mm in size. This results in large variations between competing orbital debris models. It also happens to be the size regime which poses the highest mission-ending risk to spacecraft. To evaluate the efficacy of the Arecibo Observatory for orbital debris measurements, new methods for evaluating the efficacy of bistatic radars for orbital debris measurements were developed. These include a new tool for calculating the lateral surface area of a bistatic radar, a method to calculate a minimum detectable debris size, and an algorithm to estimate a sensitivity-limited total count rate of debris for an observation. Each of these were validated by comparisons to debris data collected by the Haystack Ultrawideband Satellite Imaging Radar (HUSIR), the primary orbital debris radar used by NASA. Using these validated methods, the performance of the Legacy Arecibo Telescope (LAT) and the Next Generation Arecibo Telescope (NGAT) for orbital debris measurements is estimated. It is then shown that, with appropriate hardware upgrades, it would be possible to achieve a minimum detectable debris size as small as 1 mm. These capabilities would allow data from Arecibo to significantly improve short-term debris environment models which are used to inform spacecraft design and operations, particularly for orbital debris smaller than 3 mm, which pose the highest penetration risk to most spacecraft.