Monitoring vegetation tipping elements with Moon-based SAR: wind-induced impacts of unstable scattering

Moon-based synthetic aperture radar (SAR) offers a promising platform for long-term monitoring with global coverage of Earth's vegetation tipping elements. However, wind-induced vegetation motion during aperture synthesis can degrade image stability and spatial resolution. To address this, we integrated multi-year wind speed records, a parameterized internal clutter motion model, and Moon-based SAR geometry to systematically analyze the dynamic scattering behavior across representative vegetation types under prevailing wind conditions. The results reveal two distinct degradation mechanisms: high-latitude sensitivity, driven by orbital geometry, and high-biomass severity, driven by vegetation structure. Crucially, we demonstrate that the unique ultra-high orbit enables Moon-based SAR to overcome these challenges, achieving sub-100 m resolution across all representative ecosystems by surpassing the traditional half-antenna length limit. Furthermore, the analysis indicates that C-band may be preferentially considered in system design, as it achieves a comparatively favorable trade-off between temporal coherence required for imaging stability and structural sensitivity across diverse vegetation conditions. These findings support the design and capability assessment of Moon-based SAR systems optimized for vegetation observation in the context of ecosystem transition monitoring.