• sivam
• sar
• low-cost mission
• small satellite
• vlm-1

This thesis is aimed at analyze and design a low-cost constellation of small SAR satellites to improve the SIVAM surveillance capability, in order to detect noncooperative targets in Brazilian Amazon borders. The analysis also considers the Brazilian Microsatellite Launcher VLM-1, such as the launcher vehicle from Alcantara Launch Range. Several constellations architectures have been evaluated, in order to satisfy the user’s requirements and constraints, such as spatial resolution needed to detect the targets, frequency of satellite revisit, geographical coverage area, ground stations locations, and launcher interfaces and performance constraints. The mission architecture design includes: the SAR system design that determines parameters such as antenna dimensions, sensor coverage, pulse repetition frequency, radar timing, data rate, power consumption and mode of operation; a study of alternative mission concepts of MTI, in detection of the target, considering the imaging processing on-board and on ground; a coverage analysis in STK software to determine the orbital parameters, the operation time and gaps between operation periods; and a space-time-coverage analysis to identify the number of satellites and the daily surveillance of possible constellations. A small platform equipped with a light SAR payload based on recent technological improvements of inflatable SAR antennas has been designed. The platform, equipped with components on-the-self, offers a suitable performance in terms of power generation, data storage, data transmission and pointing accuracy. Also a detailed representation of internal and external layouts and the satellite assembly with the VLM-1 upper stage inside the fairing are shown, together with the satellite mass budget and the final system performance.