Based On The Raman Scattering Spectra Of Water Salinity Remote Sensing Detection Method And Experimental Research

Seawater salinity is one of the important basic physical parameters in the detection of marine underwater targets.For the simulation of water cycles,the verification of improved climate modeling methods,and the survival and distribution of various types of biological life in the ocean,survival and reproduction,etc.The precise detection of marine underwater targets in the defense industry has important research significance.Therefore,in recent years,more and more researchers have carried out exploration research on seawater salinity.At present,salinity detection methods based on water bodies are mostly based on contact or surface detection,such as spaceborne detection based on high-precision conductivity method onboard CTD instrument or buoy detection and microwave remote sensing technology.Obtain salinity information from a large measurement range.Among them,the method of Raman scattering method for measuring salinity of water,combined with lidar technology,can achieve the advantages of non-contact,large area and real-time detection of salinity detection,so it has been paid more and more attention.This article are used to study the process of measuring the salinity of seawater by Raman scattering method.In view of the characteristics of weak Raman scattered light intensity and complex components in seawater,the design and construction of an experimental system for detecting Raman scattering spectroscopy in water bodies are maded,then based on the analysis of the composition of seawater,prepare related solutions,and compare the effects of different anions and cations in seawater on Raman scattering spectra.The main work and research results of the thesis are:First,for the characteristics of weak Raman scattering intensity,based on the transmission window of seawater and Raman scattering characteristics,we use optical path design software for optical path simulation design verification,select the appropriate excitation light source subsystem,and enhance the subsystem;in order to achieve real-time detection obtain a clear Raman scattering spectrum,calculate and analyze the required spectral resolution of 0.05nm,choose a monochromator PI Acton SP2500 and PI-MAX-3 ICCD combined with computer-side data acquisition,and build an experimental system to detect Raman scattering spectrum to Raman spectra clearly in real time.Secondly,according to the intensity formula of the liquid Raman scattering spectrum,the spectrum of the solution at different temperatures and different concentrations is simulated for comparison and verification with the experimental results;the log area ratio method and the Gaussian peak separation method are proposed to obtain the Raman scattering.The characteristic peaks in the spectrum that reflect the changes in salinity are subjected to inversion analysis to obtain information on changes in salinity of the water body,and the residual sum of squares,correlation coefficients,and error information of the fitted linear relationship are compared and analyzed.Finally,for the analysis of the components in seawater,different solutions were prepared for the more inorganic salt ions Cl-,Na+,Mg2+,and SO42-,and the Raman spectroscopy detection system of the single solution was used to obtain the Raman spectrum,and then the intensity information of the spectrum is compared and analyzed to study different anions and cations.Combined with the actual range of seawater salinity,the raman spectra of solutions with different concentrations(29.12 ‰,31.01 ‰,32.88 ‰,34.75 ‰,36.61 ‰)were obtained through experiments,and the theoretically verified gaussian peak method was used for different concentrations The data processing of the raman spectroscopy shows that the linear relationship of water salinity is S=(99.003-y)/162.778,the correlation coefficient is 0.982,the sum of squared residuals is 0.474,and the error is ± 0.158,which verifies the feasibility of this scheme.