Bubble release flux quantification method based on acoustic signal

Abstract

The invention discloses a bubble release flux quantification method based on an acoustic signal. The method comprises the steps of 1 removing a reverberation signal; 2 acquiring acoustic characteristics of bubbles; 3 calculating inherent attributes of the bubbles; and 4 calculating bubble release flux. The calculation formula in the step 4 is as follows: in the formula, rho (mL / m < 3 >) is the bubble concentration in water, v (m / s) is the rising speed of bubbles, P is the actually measured atmospheric pressure of a sampling point, and P0 is the standard atmospheric pressure (1013.25 hPa). Thestep 1 comprises the steps of 1 observing an echo graph, determining a bubble distribution range, and eliminating noise outside the range by setting a threshold value to realize first denoising; and 2manually defining an invalid data area, carrying out secondary denoising, and removing sailing noise and fish signals. The acoustic technology is adopted to perform signal acquisition on bubbles, continuous monitoring and comprehensive capture of bubble discharge information can be realized in a large water area, the efficiency is high, and the coverage area is large.

Description

technical field [0001] The invention relates to the technical field of acoustic detection, in particular to a method for quantifying bubble release flux based on acoustic signals. Background technique [0002] Methane in water is produced by anaerobic degradation of organic matter and rises gradually, mainly in the form of bubbles, before entering the atmosphere. There are many freshwater rivers, lakes, and reservoirs in my country, with rich vegetation, and a large amount of organic matter enters the water body with the water flow; in addition, human activities lead to eutrophication of the water body, and the flourishing algae cannot be exported through the food chain and are deposited at the bottom of the water. The decomposition of organic matter at the bottom of the water will emit a large amount of greenhouse gases, leading to a continuous rise in global temperature and an increasingly significant greenhouse effect. Therefore, the study and quantification of air bubble...

AI Technical Summary

Problems solved by technology

Traditional bubble release statistics generally use gas collection, optical video or picture shooting. For example, the method for counting the number of leaking bubbles in a water body and the processing terminal disclosed by the publication number CN109598739A discloses a method for counting the number of bubbles through optical video shooting. , this method counts the number of bubbles in each frame of the captured optical video, and then obtains the bubble release flux. However, the above method is limited to shallow water and small-scale water research, and cannot realize continuous monitoring and comprehensive capture of bubble emission information on large water surfaces. , and its calculation method is cumbersome and inefficient, and there is still no way to quantify the release of air bubbles on large water surfaces

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