Aiming at the problems of high costs,maintenance difficulties and inaccuracies in traditional measurement methods of river flow velocity,the paper proposed a method of global navigation satellite system-reflectometry (GNSS-R) velocity inversion considering river directions:it was pointed out that the river flow direction and scattering geometry would affect the GNSS-R velocity inversion,and the Doppler effect generated by the movement of GNSS signals in relation to reflecting surfaces was used for flow velocity measurement;then,the measured data of acoustic Doppler current profiler (ADCP) was introduced to verify the inversion results,and the influence of scattering effect on Doppler frequency shift under different geometric configurations was analyzed;finally,the GNSS-R flow velocity inversion technology was improved.Experimental results showed that in the backward configuration,the flow velocity would be generally higher than that in the forward configuration;moreover,the inversion results based on the Doppler frequency difference of backward configuration would be similar to the measured flow velocity,but the error could be large because the Doppler frequency is difficult to capture accurately.
global navigation satellite system-reflectometry (GNSS-R)velocity measurementscattering geometrystream directionDoppler frequency