Lunar explorations have received increasing attention in recent years with tremendous application values, including using the Moon as a remote sensing platform for Earth observation. As an active sensor, the Synthetic Aperture Radar (SAR) can detect changes in the atmosphere, terrain, and ocean. Moon-based SAR, complementary to the spaceborne SAR systems, expands our capabilities of watching and understanding the Earth. This book explains the Moon-Earth observation geometry, generic parameters, image focusing, and outlook using the Moon-based SAR. Written as a SAR imaging of Earth on the lunar-based platform, it makes it an essential reference to those interested in planetary and Earth sciences. FEATURES Uses the Moon as a remote sensing platform for Earth observation Explains how to obtain a high spatial resolution with a short revisit time using the Moon-based SAR Covers the observation geometry, range and signal models, two-dimensional signal spectrum, and focusing algorithms for the Moon-based SAR Presents a detailed analysis of sources of phase errors in the Moon-based SAR signal Includes global case studies and introduces conceptual ideas for further research This book is intended for senior graduate students, professional researchers, and engineers studying and working in the fields of lunar exploration and remote sensing applications, especially when dealing with high-orbit SAR studies.