Author(s): Victor Herraiz-Lopez; Inigo Salinas; Maria Luisa Moreno; Jose Ramon Sanchez; Pilar Blasco; Adrian Subias; Rafael Alonso
Linked Author(s):
Keywords: FMCW radar; Portable instrumentation; Surface velocity radar (SVR); X-band radar
Abstract: Surface Velocity Radars (SVRs) are emerging as a key technology for non-contact flow monitoring, complementing image-based and acoustic techniques. This study presents a low-cost, portable X-band frequency-modulated continuous wave (FMCW) SVR with beamforming capabilities, developed to evaluate the feasibility of rapid and autonomous river surface velocity estimation without permanent installation. The radar operates from 10 to 10.5 GHz with a 500 MHz bandwidth, providing high-resolution range–velocity (R–V) maps of backscattered echoes from the water surface. Preliminary field experiments were conducted on the Gállego River, a tributary of the Ebro Basin (Spain), under the Ebro River Basin Authority. The radar yielded stable backscatter returns and well-defined Doppler spectra, confirming good surface reflectivity. The resulting R–V maps are qualitatively consistent with simulated hydrodynamic velocity profiles, supporting the validity of the FMCW-based measurement approach. The instrument’s portability, low power consumption, and lack of deployment requirements make it suitable for hydrological applications in remote or hazardous environments. Future work will extend this concept to an angular-scanning SVR configuration, enabling two-dimensional mapping of the surface velocity field for improved discharge estimation and integration into distributed, low-cost radar networks for operational river monitoring.
Year: 2026