Calibration, selection and mosaicing of SMART-1 AMIE images

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

Small Missions for Advanced Research in Technology (SMART-1), represented European Space Agency (ESA) first mission to the moon. It fulfilled the goal of improving the scientific knowledge of earth’s natural satellite, while testing new technologies that had never been used in space exploration. Among the on board instruments of SMART-1 was the Advanced Moon micro-Imager Experiment (AMIE). It was an imaging equipment whose mission was to map the lunar surface providing state-of-the-art resolution. Containing six filters inside its visual scope AMIE allowed the study of the surface composition by multispectral imaging. This thesis aims at building a set of maps covering approximately all the Moon surface as it was mapped by the SMART-1 spacecraft, using the 31945 images captured by the AMIE instrument. During the Earth escape phase the instrument’s CCD was damaged by radiation, causing the accumulation of dark current and invalidating the laboratorial image calibration algorithm. The acquired dataset also suffered from scattered light that got beneath the CCD filters and reduced their contrast. In order to overcome this problem, a new calibration procedure was developed using the in-flight collected data and theoretical models, as well as a method to compensate for the reduced contrast in the filters. For building the lunar maps, the images were individually analysed and classified accordingly to their visual quality and grouped by their illumination conditions, allowing the creation of visually balanced maps. Image mosaicing and projection techniques were used to compensate the geometrical distortions and compose the calibrated images into a set of 88 maps of the Moon. Increasing the flexibility of the process, a comprehensive tool that allows the edition of the images in the mosaiced maps, as well as brightness and contrast correction and adjustment is also presented.