Backscattering of Microwaves by Freshwater Ice at Low Incidence Angles

The paper presents the results of a series of experiments performed in February-March 2023. An X-band radar was installed on the metro bridge across the Oka River in Nizhny Novgorod. The radar worked in the radio altimeter mode and the waveform of the reflected pulse was recorded (the dependence of the power of the reflected signal on time). As a result of processing, the distance to the reflection area on the surface was determined. Dependences of the power of the radar signal reflected by the ice cover on the incidence angle were obtained. The air temperature was recorded synchronously with the measurements. The change in the distance to the area of reflection on the surface was associated with a change in the water level in the Oka River. Dependences of the power of the reflected signal on the angle of incidence were plotted for a radar with a knife-like antenna beam for different days of measurements. Based on empirical data, a formula is obtained for the angular dependence of the power of reflected microwave signal for fresh ice cover.