Synthetic Aperture Radar for Earth Observation from a Lunar Base: Performance and Potential Applications

Starting from the reborn international interest in lunar exploration and the widely documented need for hyper-accurate measurements of Earth crustal dynamics, at a high revisit frequency and on a global scale, the idea of a Moon-based interferometric synthetic aperture radar (SAR) is presented. After introducing models to describe synthetic antenna formation and discussing key issues of a Moon-based radar for Earth remote sensing, a preliminary system design and performance analysis are conducted. Quantitative results are presented in terms of achievable resolutions and needed radar parameters. Although the Moon-based observatory requires technical solutions and a budget that likely make its realization distant, a comparison with currently planned spaceborne interferometric systems shows that it offers height measurement accuracies at a level and with a frequency not achievable otherwise.