A Dual-Mode FMCW-Doppler Radar with a Frequency Scanning Antenna for River Imaging Applications

This paper presents a novel frequency modulated continuous wave radar with imaging capability, purposely designed for river monitoring applications. Radar images are obtained using a fixed antenna whose beam can be steered according to the excitation frequency. This is achieved by means of a planar array of slots with a custom feeding network featuring marked frequency squint effects. The radar prototype is experimentally validated in significant scenarios such as those related to static object detection and river water level estimation. The prototype operates in the 24 GHz frequency band and can produce real time 2D radar maps with a simple signal processing and hardware, the latter implemented in a Raspberry Pi single board computer. The proposed architectures open new prospectives in the field of river monitoring with non-contact sensors, proving how it is possible to properly detect water level, an essential parameter used to estimate the river discharge.