CN-121978056-A - Hydrocarbon pollution detecting method and device by coupling spectrum difference and characteristic T test

CN121978056ACN 121978056 ACN121978056 ACN 121978056ACN-121978056-A

Abstract

The invention provides a hydrocarbon pollution detection method and a device for coupling spectrum subtraction and characteristic T test, which belong to the technical field of environmental monitoring, and the method comprises the steps of obtaining target near infrared spectrum data of a region to be detected, determining corresponding background near infrared spectrum data according to the type of ground object of the region to be detected, wherein the background near infrared spectrum data is reference spectrum data which is the same ground object as the target to be detected and is not polluted by hydrocarbons; the method comprises the steps of performing subtraction processing on target near infrared spectrum data and background near infrared spectrum data to generate a difference spectrum, selecting a hydrocarbon characteristic absorption band and a reference band, performing independent sample T test on a spectrum value of the difference spectrum in the hydrocarbon characteristic absorption band and a spectrum value in the reference band, and determining a hydrocarbon pollution detection result of a region to be detected based on the test result. According to the invention, the background interference is eliminated through spectrum subtraction, an objective judgment standard is established by utilizing T test, and the scientificity and applicability of hydrocarbon pollution detection are improved.

Inventors

LOU QIJIA
GAO JIXI
XIONG WENCHENG
QU RAN
ZHANG YAQIONG
ZHOU GUANGJIN
ZHU WEIWEI
CHENG ZHIYUN
WANG YUXUAN

Assignees

生态环境部卫星环境应用中心

Dates

Publication Date: 20260505
Application Date: 20260403

Claims (8)

1. A method for detecting hydrocarbon contamination by coupling spectral subtraction with a feature T-test, comprising: Acquiring target near infrared spectrum data of a region to be detected, and determining corresponding background near infrared spectrum data according to the type of the ground object of the region to be detected, wherein the background near infrared spectrum data is reference spectrum data which is the same ground object as the target to be detected and is not polluted by hydrocarbons; performing subtraction processing on the target near infrared spectrum data and the background near infrared spectrum data to generate a difference spectrum; Selecting a hydrocarbon characteristic absorption band and a reference band from the difference spectrum, and performing independent sample T test on the spectrum value of the difference spectrum in the hydrocarbon characteristic absorption band and the spectrum value in the reference band to obtain a test result; And determining a hydrocarbon pollution detection result of the area to be detected based on the detection result.
2. The method for detecting hydrocarbon contamination by coupling spectral subtraction and characteristic T-test according to claim 1, wherein the hydrocarbon characteristic absorption band is a band corresponding to a hydrocarbon C-H bond vibration absorption frequency, the reference band is a ground object weak absorption band, and the reference band is outside the hydrocarbon characteristic absorption band.
3. The method for detecting hydrocarbon contamination by coupling spectral subtraction and characteristic T-test according to claim 2, wherein the characteristic absorption band of hydrocarbon is a band in a wavelength range of 1700nm to 1780nm, and the reference band is a band in a wavelength range of 1560nm to 1640 nm.
4. A method of hydrocarbon contamination detection coupled with spectral subtraction and feature T-test as recited in claim 3, wherein the performing independent sample T-test on spectral values of the difference spectrum in the hydrocarbon feature absorption band and spectral values in the reference band comprises: calculating a first spectrum mean value, a first spectrum variance and a first data point number of the difference spectrum in the hydrocarbon characteristic absorption band; calculating a second spectrum mean value, a second spectrum variance and a second data point quantity of the difference spectrum in the reference wave band; and calculating t statistics based on the first spectrum mean value, the first spectrum variance and the first data point quantity, the second spectrum mean value, the second spectrum variance and the second data point quantity, wherein the t statistics are used for measuring the mean difference significance of the difference spectrum in the hydrocarbon characteristic absorption band and the reference band.
5. The method for hydrocarbon contamination detection by coupling spectral subtraction and feature T-test of claim 4, wherein the T-statistic is calculated as follows: ; Wherein t represents the t statistic, Representing the first spectral mean value in question, Representing the first spectral variance of the spectrum, Representing the first number of data points; representing the second spectral mean value in question, Representing the variance of the second spectrum of light, Representing the second number of data points.
6. The method for hydrocarbon contamination detection coupled with spectral subtraction and feature T-test of claim 5, wherein the determining the hydrocarbon contamination detection result for the area to be detected based on the test result comprises: comparing the t statistic with a preset significance threshold value, and comparing the first spectrum mean value with the second spectrum mean value; and judging that the hydrocarbon pollution exists in the area to be detected if the following conditions are met simultaneously: The absolute value of the t statistic is not less than the significance threshold; the first spectral mean is less than 0; The first spectral mean is less than the second spectral mean.
7. The method for detecting hydrocarbon contamination by coupling spectral subtraction and feature T-test according to claim 1, wherein the target near infrared spectrum data and the background near infrared spectrum data satisfy a spectral range covering 1100nm to 2400nm and a spectral resolution not lower than 12nm.
8. A hydrocarbon contamination detection apparatus for coupling spectral subtraction with a feature T test, comprising: The device comprises an acquisition unit, a detection unit and a detection unit, wherein the acquisition unit is used for acquiring target near infrared spectrum data of a region to be detected, and determining corresponding background near infrared spectrum data according to the type of the ground object of the region to be detected, wherein the background near infrared spectrum data is reference spectrum data which is the same ground object as the target to be detected and is not polluted by hydrocarbons; the processing unit is used for performing subtraction processing on the target near infrared spectrum data and the background near infrared spectrum data to generate a difference spectrum; The testing unit is used for selecting a hydrocarbon characteristic absorption wave band and a reference wave band from the difference spectrum, and performing independent sample T test on the spectrum value of the difference spectrum in the hydrocarbon characteristic absorption wave band and the spectrum value in the reference wave band to obtain a testing result; and the determining unit is used for determining the hydrocarbon pollution detection result of the area to be detected based on the detection result.

Description

Hydrocarbon pollution detecting method and device by coupling spectrum difference and characteristic T test Technical Field The invention relates to the technical field of environmental monitoring, in particular to a hydrocarbon pollution detection method and device for coupling spectrum subtraction and characteristic T test. Background With the acceleration of industrialization, environmental pollution caused by hydrocarbon leakage is increasingly serious. Near infrared spectrum technology is widely applied to hydrocarbon pollution detection of environmental media such as soil, water and the like due to the advantages of rapidness, no damage, no need of sample pretreatment and the like. However, the existing near infrared spectrum detection method still has limitations in practical application. On one hand, the detection scene is usually complex, and the spectral characteristics of the ground object background often mask or interfere with the characteristic absorption of hydrocarbons, so that direct identification is difficult. On the other hand, the current determination of hydrocarbon pollution mainly depends on the spectral value of the characteristic wave band or the simple calculation thereof, and the setting of the determination threshold is often based on manual experience or fixed standards. Because the pollution degree and the environmental interference factors in the actual scene have high uncertainty, the threshold value set based on subjective experience lacks scientific basis on statistics, has poor applicability and is very easy to cause misjudgment or missed judgment of the detection result. Disclosure of Invention The invention provides a hydrocarbon pollution detection method and a device for coupling spectrum subtraction and characteristic T test, which are used for solving the defects of poor scientificity and applicability of a hydrocarbon pollution detection method in the prior art. The invention provides a hydrocarbon pollution detection method for coupling spectrum subtraction and characteristic T test, which comprises the following steps: Acquiring target near infrared spectrum data of a region to be detected, and determining corresponding background near infrared spectrum data according to the type of the ground object of the region to be detected, wherein the background near infrared spectrum data is reference spectrum data which is the same ground object as the target to be detected and is not polluted by hydrocarbons; performing subtraction processing on the target near infrared spectrum data and the background near infrared spectrum data to generate a difference spectrum; Selecting a hydrocarbon characteristic absorption band and a reference band from the difference spectrum, and performing independent sample T test on the spectrum value of the difference spectrum in the hydrocarbon characteristic absorption band and the spectrum value in the reference band to obtain a test result; And determining a hydrocarbon pollution detection result of the area to be detected based on the detection result. In some embodiments, the hydrocarbon characteristic absorption band is a band corresponding to a hydrocarbon C-H bond vibration absorption frequency, the reference band is a ground feature weak absorption band, and the reference band is outside the hydrocarbon characteristic absorption band. In some embodiments, the hydrocarbon characteristic absorption band is a band in the 1700nm-1780nm wavelength range and the reference band is a band in the 1560nm-1640nm wavelength range. In some embodiments, the performing independent sample T-test on the spectral values of the difference spectrum in the hydrocarbon characteristic absorption band and the spectral values in the reference band comprises: calculating a first spectrum mean value, a first spectrum variance and a first data point number of the difference spectrum in the hydrocarbon characteristic absorption band; calculating a second spectrum mean value, a second spectrum variance and a second data point quantity of the difference spectrum in the reference wave band; and calculating t statistics based on the first spectrum mean value, the first spectrum variance and the first data point quantity, the second spectrum mean value, the second spectrum variance and the second data point quantity, wherein the t statistics are used for measuring the mean difference significance of the difference spectrum in the hydrocarbon characteristic absorption band and the reference band. In some embodiments, the t statistic is calculated as follows: ; Wherein t represents the t statistic, Representing the first spectral mean value in question,Representing the first spectral variance of the spectrum,Representing the first number of data points; representing the second spectral mean value in question, Representing the variance of the second spectrum of light,Representing the second number of data points. In some embodiments, the determining hydrocarbon conta