CubeSat radar altimeter for oceanic monitoring

• Autor(a) principal: Castro, Mariangel Vieira
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Texto Completo: http://hdl.handle.net/10773/42029
• topic: Altimeter; CubeSat; Efficiency; Fast chirp; FMCW; Patch antenna array; Radar; Satellite

This dissertation explores Radar Altimeters (RAs) and their adaptation for CubeSat missions. Focusing on addressing CubeSat constraints, including the limitation of power consumption and the necessity of small-sized systems, the research introduces an innovative approach utilising the Frequency-Modulated Continuous Wave (FMCW) technique and a short-duration chirp to optimise efficiency while maintaining high accuracy. Firstly, the dissertation outlines a comprehensive plan for creating an energy-efficient Radar Altimeter tailored to CubeSats’s needs. To accomplish this, the research examines the different types of Radar Altimeters, their functions, and Link-Budget calculations that govern satellite communications. The selection and design process focuses on identifying the optimal radar architecture for this particular use case. During this stage, the system’s main components were developed, including the RF chain (FMCW hardware), the antennas, the power supply, and the data capture and processing mechanisms. After that, a structure for the system was designed, containing all the components, resulting in a functional CubeSat prototype. Subsequently, the dissertation explores the development of the fast-transmitted chirp technique to optimise the system’s performance and enhance overall efficiency. Finally, several testing procedures were conducted to validate the feasibility of the proposed system in various applications and environments. The results of these tests demonstrate that it is possible to create an RA prototype with the proposed characteristics that exhibit exceptional accuracy, precision, and efficiency. These findings represent a significant breakthrough in developing compact, energy-efficient radar altimeters for CubeSats.