Grid Size Optimization for Soil Moisture Estimation Using UAS-Based GNSS Reflectometry

The agriculture industry consumes 70% of the world's available freshwater, making efficient water use essential to ensuring sustainable practices. Precision agriculture, through accurate soil moisture (SM) measurements, can play a pivotal role in optimizing irrigation, reducing water wastage, and conserving critical resources. However, obtaining precise SM data across large agricultural areas remains a significant challenge. In-situ invasive SM probes can deliver highly accurate data but are limited to localized, point-based measurements that do not provide complete field coverage. Conversely, satellite-based SM measurements, such as those from the Cyclone Global Navigation Satellite System (CYGNSS), Soil Moisture Active Passive (SMAP), etc., offer extensive coverage but at resolutions (in kilometer range) that are insufficient for the high spatio-temporal accuracy required in precision agriculture.