Method of measuring sand wave shape parameters of dry river bed based on aerial survey topographic data of unmanned aerial vehicle (UAV)

Abstract

The invention discloses a method of measuring sand wave shape parameters of a dry river bed based on aerial survey topographic data of an unmanned aerial vehicle (UAV). The main technical means is toconduct UAV low-altitude aerial survey on a selected dry river bed to measure the sand wave height delta and the total wavelength lambda, and based on the requirements of sand wave topographic spatialresolutions of different dry river beds, the flight height and the overlap of the UAV are determined, and aerial survey image data are obtained. By adopting a RTK (Real-time kinematics) carrier phasedifference technology, certain characteristic elevation points are obtained for topographic data correction. The image processing tools of ArcMap, Cloud Compare, and Pix4D are used to perform depth processing of DEM data noise to obtain reliable, high-precision and high-resolution topographic data. Through final measurement and calculation, the sand wave shape parameters such as the total wavelength lambda, an upstream wavelength lambda1, a downstream wavelength lambda2, the sand wave height delta, an upstream wave angle alpha and a downstream wave angle beta of the dry river bed are obtained.

Description

technical field [0001] The invention relates to the fields of riverbed evolution, sediment movement mechanics, application of unmanned aerial vehicle aerial survey technology, terrain data processing and the like. Background technique [0002] Sand wave is a specific form formed by the collective movement of sediment particles on the river bed. It generally develops and exists in natural rivers, and is the result of the interaction between water flow, sediment and the river bed. Sand wave is an important form of moving sediment movement, and its development is closely related to riverbed resistance, near-bottom water flow and sediment movement. Natural rivers have various forms and different flow conditions. As the flow conditions increase, the sand wave form will go through several different stages of development. Waves, rapids and deep pools. The whole process is divided into two distinct stages: in the first stage, sand ripples and ridges appear; in the second stage, sa...

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Problems solved by technology

[0003] At present, the commonly used technical means and measurement methods are manual measurement or the use of side-scan sonar to intervene in the measurement of sand wave shape parameters. These traditional methods require carrying a large number of heavy tools, walking to the river bank or renting a boat, and it takes a certain amount of time to perform the measurement. The measurement area is small, the operation is cumbersome, requires a lot of labor and financial resources, and the accuracy is low, and the error caused by manual operation is large and unavoidable

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