Advancing River Monitoring: High-Resolution Surface Velocity Measurement Using Range-Doppler Radar from Moving Platforms

High-resolution hydrometric monitoring of rivers is crucial as climate change significantly impacts the frequency and intensity of extreme events, leading to rapidly evolving flood and drought risk profiles. However, hydrometric data is often limited, with insufficient spatial resolution and coverage, especially in remote or hard-to-access rivers in alpine, arctic, and tropical regions.

Traditional hydrometric monitoring relies on station-based, in-situ measurements. Parameters such as water surface elevation, flow velocity, bed geometry, and river discharge are typically recorded using sensors installed directly in or near the flow.

In this study, we analyzed velocity measurements obtained using range-Doppler radar and compared them to Doppler radar experiments. Our findings demonstrate that range-Doppler radar is more effective for measuring surface velocity from a moving platform. Here, we discuss the methodology and rationale for adopting this innovative approach in future research on water observation systems. By utilizing range-Doppler radar, we aim to achieve high-resolution, extensive spatial coverage for key hydrometric variables like surface velocity.