River flow velocity and water level inversion method of land-based GNSS reflectometer

Abstract

The invention relates to a river flow velocity and water level inversion method of a land-based GNSS reflectometer. The river flow velocity and water level inversion method comprises the following steps: acquiring a reflection signal of a GNSS signal on a river surface in a land-based scene; estimating the Doppler frequency of the reflected signal by using a Gaussian fitting method according to the reflected signal; according to the reflected signal Doppler frequency, inversing the river flow velocity by using a reflected signal bistatic geometrical relationship; obtaining a coherent signal and an incoherent signal of the reflected signal; determining an accumulation ratio according to the coherent signal and the incoherent signal; when the accumulation ratio is smaller than a set threshold value, using the fuzzy scene for water level inversion, and determining the height of the receiver relative to the river surface; when the accumulation ratio is greater than or equal to a set threshold value, performing water level inversion by using the coherent scene, and determining the height of the receiver relative to the river surface; and determining the river level according to the height of the receiver relative to the river surface and the elevation of the receiver relative to the ground. According to the invention, low-cost and high-precision detection of the flow velocity and the water level of the river can be realized.

Description

technical field [0001] The invention relates to the field of river measurement, in particular to a river velocity and water level inversion method of a land-based GNSS reflectometer. Background technique [0002] GNSS reflection signal (Global Navigation Satellite System-Reflection), which utilizes existing navigation satellite signals to realize inversion and monitoring of surface physical parameters through cooperative reception and processing of direct and ground-reflected navigation satellite signals, is a dual-base opportunity source The detection method has the advantages of low cost, low power consumption and light weight. Its L-band signal attenuation is small under rainfall conditions, which is suitable for monitoring under severe conditions such as rainfall. In addition, land-based detection can use mature multi-channel navigation radio frequency and correlator chips to complete signal processing to achieve rapid processing and monitoring. [0003] The current co...

AI Technical Summary

Problems solved by technology

Although the above-mentioned non-contact monitoring methods supplement the observation of hydrological information of rivers in larger scales and underdeveloped areas to a certain extent, they have the following deficiencies: 1) They are all targeted monitoring of single parameters such as river boundaries, water levels, and flow rates ( For example, VHF ground wave radar is only used for flow rate monitoring); 2) All parameters such as river boundary, water level, flow rate and measured river flow are used to establish empirical relationship to realize river monitoring; 3) Space-borne altimeter, SAR, multi-spectral and other remote sensing means Due to the influence of resolution and atmosphere, it is restricted in narrow river areas, rainfall and other harsh conditions, and has low time sampling rate, poor real-time performance, high cost and power consumption

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