Fire point source pollutant emission monitoring method and system based on time sequence

Abstract

The invention provides a fire point source pollutant emission monitoring method and system based on a time sequence. The method specifically comprises the following steps: acquiring multispectral image data of a satellite, when a fire disaster is monitored, reading the radiation brightness of light of an observation image during the fire disaster, calling image data in a set period before the fire disaster in a fire disaster occurring area as a reference image, and obtaining the radiation brightness of light of a background reference image according to the radiation brightness of the light of each reference image; establishing an optical radiation absorption model of the fire point source pollutants; calculating an attenuation value between the radiation brightness of the light of the observation image and the radiation brightness of the light of the background reference image during the fire, and obtaining a radiation brightness absorption coefficient of the light of the pollutant based on the attenuation value and a light radiation absorption model of the fire point source pollutant; and comparing the calculated radiation brightness absorption coefficient of the absorbed light of the pollutants with the HIRAN database, thereby realizing accurate detection and quantification of pollutant emission after the fire.

Description

Technical Field

[0001] The present invention relates to the technical field of atmospheric environmental pollution research, and in particular to a method and system for monitoring pollutant emissions from fire point sources based on time series. Background Art

[0002] Fires have a serious impact on the ecological environment and human health, especially in the context of climate change and global warming, as fires are becoming more frequent and more intense, leading to large-scale pollutant emissions. Currently, satellite technology has been widely used in fire monitoring, mainly to detect the existence and location of fire points. However, existing satellite fire monitoring technology is mainly limited to the discovery of fire points, and there is still a technical shortage in monitoring and quantifying point source pollutant emissions caused by fires. Summary of the invention

[0003] In order to overcome the defects in the prior art mentioned above, the purpose of the present invention is to provide a method and system for monitoring the emission of pollutants from point fire sources based on time series.

[0004] In order to achieve the above-mentioned object of the present invention, the present invention provides a method for monitoring the emission of pollutants from fire point sources based on time series, comprising the following steps:

[0005] Obtain multispectral image data from satellites to monitor fires;

[0006] When a fire is detected, the radiation brightness of the light of the observation image during the fire is read, and the image data of the fire area within a set period before the fire occurs is retrieved as a reference image, and the radiation brightness of the light of the background reference image is obtained according to the radiation brightness of the light of each reference image;

[0007] Establish a light radiation absorption model for fire point source pollutants based on the light radiation brightness of the fire observation image;

[0008] The ratio between the radiant brightness of the light of the observation image during the fire and the radiant brightness of the light of the background reference image is calculated, and the radiant brightness absorption coefficient of the light of the pollutant is obtained based on the attenuation value and the light radiation absorption model of the pollutant from the fire point source;

[0009] The calculated radiation brightness absorption coefficient of the absorbed light of the pollutants is compared with the HIRAN database to monitor and quantify the pollutant emissions from fire point sources.

[0010] Optionally, a least squares norm operation is performed on the radiant brightness of the light of each reference image to determine the best reference image, and the radiant brightness of the light of the best reference image is used as the radiant brightness of the light of the background reference image.

[0011] Optionally, the steps for establishing the light radiation absorption model of fire point source pollutants are:

[0012] Determine the radiance of light received by satellite sensors;

[0013]

[0014] Where I is the radiance of light received by the satellite sensor, s(λ) is the function of the satellite viewing angle, α(λ) is the ground reflection coefficient, I0 is the initial radiance of sunlight, and A i (λ) is the radiation intensity absorption coefficient of the light at wavelength λ of pollutant i before the fire occurs, N is the type of pollutant, l i It refers to the equivalent optical path length of pollutant i before the fire occurs;

[0015] The light radiation absorption model of the fire point source pollutants when a fire occurs is determined based on the radiation brightness of the light received by the satellite sensor:

[0016]

[0017] Where:

[0018] I Δ The radiance of the light used to observe the image during a fire;

[0019] A iΔ (λ) is the radiation intensity absorption coefficient of the light emitted by the fire pollutant i at wavelength λ;

[0020] l iΔ is the equivalent optical path length of pollutant i emitted by the fire.

[0021] Optionally, the step of calculating the radiation brightness absorption coefficient of the light of the pollutant is:

[0022] Calculate the ratio: Among them, I t is the radiance of the light of the background reference image, I Δ The radiance of the light used to observe the image during a fire;

[0023] According to the formula Calculate the radiation brightness absorption coefficient A of the light of pollutant i at wavelength λ during fire iΔ (λ).

[0024] The present application also proposes a fire point source pollutant emission monitoring system, including a processing unit, a storage unit and a satellite multispectral image data acquisition unit;

[0025] The satellite's multispectral image data acquisition unit is connected to a processing unit and sends the multispectral image data to the processing unit. The processing unit is connected to a storage unit, and the storage unit is used to store at least one executable instruction. The executable instruction enables the processing unit to perform operations corresponding to the above-mentioned time series-based fire point source pollutant emission monitoring method according to the multispectral image data to monitor the fire point source pollutant emission.

[0026] The beneficial effects of the present invention are: the present invention can not only accurately monitor the existence of fire points, but also establish an absorption model of fire point source pollutants through the radiation brightness during the fire, combined with the time series background reference image and the HITRAN database, to achieve accurate detection and quantification of pollutant emissions after the fire. This method can effectively improve the efficiency of monitoring pollutant emissions after the fire, and provide strong technical support for global environmental protection and climate change research.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 It is a schematic diagram of the process of embodiment 1;

[0030] Figure 2 It is a satellite multispectral image of the explosion accident at Deqiao Chemical Logistics Warehouse in Danhua Village, Jingjiang City, Jiangsu Province on April 22, 2016;

[0031] Figure 3 It is a result schematic diagram of Example 1. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0033] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0034] Embodiment 1

[0035] like Figure 1 As shown, the present invention provides an embodiment of a method for monitoring the emission of pollutants from point sources of fire based on time series. This embodiment takes the explosion accident of Deqiao Chemical Logistics Warehouse in Danhua Village, Jingjiang City, Jiangsu Province on April 22, 2016 as an example. Specifically, the following steps are included:

[0036] Acquire multispectral image data from satellites.

[0037] This embodiment takes Sentinel-2 and Landsat-8 satellites as examples to obtain multispectral image data of Sentinel-2 and Landsat-8 satellites, covering a wide spectral range, including two shortwave infrared bands (SWIR1 and SWIR2) for monitoring fire points.

[0038] Data preprocessing: Perform atmospheric correction on multispectral image data, use tools such as SEN2COR and LEDAPS to eliminate the influence of atmosphere on images, and perform radiation correction and geometric correction on image data to ensure the consistency of spectral reflectance of different images.

[0039] Active fire monitoring: Use short-wave infrared bands (B11 and B12 of Sentinel-2, B6 and B7 of Landsat-8) to detect fires. Based on the existing fire detection algorithm, identify the high temperature area in the image and determine the location of the fire. The specific discriminant function is as follows:

[0040] λ 2.201 / λ 0.865 >1.4andλ 2.201 / λ 1.609 >1.4andλ 2.201 >0.15

[0041] Among them, λ is the reflectivity of the wavelength corresponding to the band.

[0042] like Figure 2 As shown, a fire was detected.

[0043] Time series data analysis, construction of background reference images:

[0044] When a fire is detected, the image data of the fire area within a set period before the fire occurs is retrieved as the reference image data based on the time series, and the radiation brightness of the light of the background reference image is obtained according to the radiation brightness of the light of each reference image. t The specific calculation steps are:

[0045] The radiant brightness of the light of each reference image is calculated by the least square norm to determine the best reference image, and the best reference image is used as the background reference image. The radiant brightness of the light of the best reference image is the radiant brightness of the light of the background reference image. t The background reference image and the observation image at the time of the fire form an "image pair".

[0046] Establishing a light radiation absorption model of fire point source pollutants based on the radiation brightness of light observed in the fire image: In this embodiment, the model is established based on the Beer-Lambert law. The specific steps are as follows:

[0047] First, determine the radiance of the light received by the satellite sensor:

[0048]

[0049] Among them, I is the radiant brightness of the light received by the satellite sensor, s(λ) is the function of the satellite viewing angle, α(λ) is the ground reflectance coefficient, both of which are functions related to wavelength and can be obtained from the satellite official website, I0 is the initial radiant brightness of sunlight, A i (λ) is the radiation intensity absorption coefficient of the light at wavelength λ of pollutant i before the fire occurs, N is the type of pollutant, l i It refers to the equivalent optical path length of pollutant i before the fire occurs.

[0050] The light radiation absorption model of fire point source pollutants determined based on the radiation brightness of light received by satellite sensors when a fire occurs is:

[0051]

[0052] Where:

[0053] I Δ is the radiation brightness of the light observed in the fire image, that is, the radiation brightness of the light received by the satellite sensor during the fire, which is a known value; A iΔ (λ) is the radiation intensity absorption coefficient of the light emitted by the pollutant i at wavelength λ; l iΔ is the equivalent optical path length of pollutant i emitted by the fire.

[0054] The attenuation value between the radiant brightness of the light of the observation image during the fire and the radiant brightness of the light of the background reference image is calculated, and the radiant brightness absorption coefficient of the light of the pollutant is obtained based on the attenuation value and the light radiation absorption model of the fire point source pollutant. Specifically,

[0055] The ratio between the radiance of the light from the observation image during a fire and the radiance of the light from the background reference image is

[0056] According to the formula Calculate the radiation brightness absorption coefficient of the light of pollutant i at wavelength λ during fire, that is, A iΔ (λ).

[0057] A iΔ (λ) is related to the type, concentration, temperature and pressure of the pollutant. The existing HITRAN database has collected the radiation brightness absorption coefficients of light of various wavelengths under various external conditions (such as different concentrations and temperatures). Therefore, the calculated radiation brightness absorption coefficient A of the absorbed light of the pollutant is iΔ By comparing (λ) with the HIRAN database, the emission concentrations of different pollutants from the fire point source can be quantified, and finally the monitoring and quantification of the emission pollution from the fire point source can be realized. The monitoring results of this embodiment can be visualized as shown in Figure 3 shown.

[0058] Embodiment 2

[0059] The present application also provides a fire point source pollutant emission monitoring system, including a processing unit, a storage unit and a satellite multispectral image data acquisition unit; the satellite multispectral image data acquisition unit is connected to the processing unit and sends the multispectral image data to the processing unit, the processing unit and the storage unit are interconnected, and the storage unit is used to store at least one executable instruction, which enables the processing unit to perform the operation corresponding to the fire point source pollutant emission monitoring method based on time series described in Example 1 according to the multispectral image data, so as to monitor the fire point source pollutant emission.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0061] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for monitoring pollutant emissions from fire point sources based on time series, characterized in that: The following steps are involved: Obtain multispectral image data from satellites to monitor fires; When a fire is detected, the radiation brightness of the light of the observation image during the fire is read, and the image data of the fire area within a set period before the fire occurs is retrieved as a reference image, and the radiation brightness of the light of the background reference image is obtained according to the radiation brightness of the light of each reference image; Establish a light radiation absorption model for fire point source pollutants based on the light radiation brightness of the fire observation image; The ratio between the radiant brightness of the light of the observation image during the fire and the radiant brightness of the light of the background reference image is calculated, and the radiant brightness absorption coefficient of the light of the pollutant is obtained based on the attenuation value and the light radiation absorption model of the pollutant from the fire point source; The calculated radiation brightness absorption coefficient of the absorbed light of the pollutants is compared with the HIRAN database to monitor and quantify the pollutant emissions from fire point sources.

2. The method for monitoring pollutant emissions from fire point sources based on time series according to claim 1 is characterized in that: The radiant brightness of the light of each reference image is subjected to a least squares norm operation to determine the best reference image, and the radiant brightness of the light of the best reference image is used as the radiant brightness of the light of the background reference image.

3. The method for monitoring pollutant emissions from fire point sources based on time series according to claim 1 is characterized in that: The steps to establish the light radiation absorption model of fire point source pollutants are: Determine the radiance of light received by satellite sensors; Where I is the radiance of light received by the satellite sensor, s(λ) is the function of the satellite viewing angle, α(λ) is the ground reflection coefficient, I0 is the initial radiance of sunlight, and A i (λ) is the radiation intensity absorption coefficient of the light at wavelength λ of pollutant i before the fire occurs, N is the type of pollutant, l i It refers to the equivalent optical path length of pollutant i before the fire occurs; The light radiation absorption model of the fire point source pollutants when a fire occurs is determined based on the radiation brightness of the light received by the satellite sensor: Where: I Δ The radiance of the light used to observe the image during a fire; A iΔ (λ) is the radiation intensity absorption coefficient of the light emitted by the fire pollutant i at wavelength λ; l iΔ is the equivalent optical path length of pollutant i emitted by the fire.

4. The method for monitoring pollutant emissions from fire point sources based on time series according to claim 1 is characterized in that: The steps for calculating the radiance absorption coefficient of the light of the pollutant are: Calculate the ratio: Among them, I t is the radiance of the light of the background reference image, I Δ The radiance of the light used to observe the image during a fire; According to the formula Calculate the radiation brightness absorption coefficient A of the light of pollutant i at wavelength λ during fire iΔ (λ).

5. A fire point source pollutant emission monitoring system, characterized in that: It includes a processing unit, a storage unit and a satellite multispectral image data acquisition unit; The satellite's multispectral image data acquisition unit is connected to a processing unit, and sends the multispectral image data to the processing unit. The processing unit is connected to a storage unit, and the storage unit is used to store at least one executable instruction. The executable instruction enables the processing unit to perform an operation corresponding to the method for monitoring fire point source pollutant emissions based on time series according to any one of claims 1 to 4 according to the multispectral image data, so as to monitor the fire point source pollutant emissions.

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