Method for measuring flow velocity of river water surface based on buoy of GNSS equipment

Abstract

The invention discloses a method for measuring the flow velocity of the water surface of a river through a buoy based on GNSS equipment, and the method comprises the following steps: installing the GNSS equipment on the buoy, and enabling the GNSS equipment to have the function of outputting GGA data and VTG data; the buoy is thrown to the upstream of the upper section and drifts along with water flow, and the buoy receives GGA data and VTG data of the GNSS equipment in real time in the process of passing through the upper section, the middle section and the lower section; the GGA data is used for determining the position of the buoy moving along with the water flow, and the VTG data is used for determining the river flow velocity of the current track point; recording all received VTG data when the buoy drifts between the upper section and the lower section, and taking the average value as the water surface flow velocity of the middle section position. According to the method, the GNSS is not required to be in a differential positioning mode, only positioning signals of a satellite need to be received, and river buoy water surface flow velocity measurement can be realized by adopting a single-machine GNSS module with relatively high cost performance.

Description

technical field [0001] The invention relates to a method for measuring the flow velocity of river water surface by a buoy based on GNSS equipment, and belongs to the technical field of hydrological measurement. Background technique [0002] The buoy method to measure the surface velocity is stipulated in the National Standard of the People's Republic of China, "River Flow Test Specifications" (GB50179-2015). The position of the buoy passing through the interrupted surface is mainly determined by positioning methods such as a total station. [0003] To measure the flow with a buoy, it is necessary to set up three sections, namely upper section, middle section and lower section. The buoy should be put into the water upstream of the upper section, and the drop can be carried out by using a buoy thrower, or by using a bridge or boat. Observe and record the time when the buoy passes through the upper and lower sections and the distance from the starting point when passing throu...

AI Technical Summary

Problems solved by technology

Therefore, when the flow rate is low, if GNSS GGA is used to measure the flow rate, the positioning accuracy of the GNSS equipment is relatively higher, otherwise the error of the measured flow rate will be greater, which cannot meet the accuracy required by the specification

In the case of high flow rate or emergency monitoring, the water flow in the river is turbulent at this time, and it is difficult to recover the dropped GNSS equipment, but the high-precision GNSS equipment is expensive, which also adds difficulties to the promotion and application of high-precision GNSS equipment.