Satellite remote sensing-based method for measuring and calculating NO2 emissions of ships

Abstract

The application provides a satellite remote sensing-based ship NO2 emission calculation method, and comprises the following steps: obtaining satellite remote sensing images and ship AIS data, identifying ship exhaust plume bands and background pixels, calculating ship exhaust plume band and background NO2 concentration, and calculating the NO2 emission of the ship per unit time. The application uses the ground NO2 concentration monitoring data of the atmospheric pollution remote sensing satellite, combines the real-time AIS data of the ship identity and positioning, and realizes the top-down ship atmospheric pollutant emission monitoring.

Description

TECHNICAL FIELD

[0001] The application relates to a ship atmospheric pollutant emission calculation method, in particular to a ship NO2 emission calculation method using atmospheric pollution remote sensing satellite monitoring data. BACKGROUND

[0002] The calculation of ship atmospheric pollutant emission is very important, which is not only a scientific basis for the emission reduction policy, but also a basis for evaluating the effect after the implementation of the emission reduction policy. However, there is no provision and requirement for online monitoring of ship atmospheric pollutant emission at home and abroad, so that the calculation of ship atmospheric pollutant emission can only be estimated. At present, the emission of each ship is estimated based on the speed information in the ship AIS, combined with the rated power of the engine designed by the ship and the rated speed parameters of the ship, the engine power during the ship sailing is estimated, and then the atmospheric pollutant emission parameters under different engine powers are used to estimate the atmospheric pollutant emission. However, the ship speed is related to the engine power, and is also related to the external environment such as wind resistance and tidal current, so the calculation process of the atmospheric pollutant emission data of the ship is complex and the error is large.

[0003] With the continuous development of atmospheric pollution remote sensing satellites, the spatial resolution of atmospheric observation on the ground has been greatly improved, and the highest resolution has reached 5km resolution, which provides the possibility for the top-down ship atmospheric pollutant emission monitoring based on satellite remote sensing, and the global or regional ship atmospheric pollutant emission calculation, so we improve it and propose a ship NO2 emission calculation method based on satellite remote sensing. SUMMARY

[0004] The purpose of the present application is to solve the problems existing in the background art. In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0005] A ship NO2 emission calculation method based on satellite remote sensing is provided to improve the above-mentioned problems, and the application is as follows: S1, satellite remote sensing images and ship AIS data are acquired, atmospheric pollution remote sensing satellite orbits are used to acquire grid format atmospheric pollution remote sensing images, and ship AIS data in a spatial range [t-i, t] time range is screened from all ship AIS data;

[0006] S2, after the satellite remote sensing images and the ship AIS data are acquired, the ship exhaust plume belt and the background pixels are identified, wherein the pixels in the ship exhaust plume belt polygon region are regarded as the ship exhaust plume belt pixels;

[0007] S3, the NO2 concentrations of the ship exhaust plume belt and the background are calculated;

[0008] After obtaining the ship's exhaust plume and background NO2 concentration, S4 calculates the ship's NO2 emissions per unit time.

[0009] As a preferred technical solution of this application, step S1 acquires satellite remote sensing images and ship AIS data. Through the orbit of an atmospheric pollution remote sensing satellite, it acquires raster-format atmospheric pollution remote sensing images with a resolution of r, meaning each pixel covers an area of ​​r. 2 The value of each pixel represents the NO2 column concentration C within the pixel's coverage area. The image was captured at the time t. A specific range a covering the ship's route was manually set, and the image was cropped.

[0010] As a preferred technical solution of this application, during the image cropping process, a tail gas diffusion duration i is set, and ship AIS data within the spatial range [ti,t] and time range of all ship AIS data are filtered, i.e., a series of [p] x ,t x Dataset, t x Within the time range [ti,t], p x Including longitude and latitude, for the ship's t x The position corresponding to the given time.

[0011] As a preferred technical solution of this application, the S2 identifies the ship's exhaust plume and background pixels to obtain p. x Average wind speed and direction data vw obtained from meteorological monitoring satellites within the time range of location [ti,t]. x Set the gas mass expansion rate v e v e It can be a constant or an arbitrary variable representing the expansion rate of the air mass, which varies with time.

[0012] As a preferred technical solution of this application, the S2 calculates the upper boundary node eu of the ship's exhaust gas diffusion location. x and lower boundary node el x ;

[0013] eu x =p x +(vw x -ve)×(tt x )

[0014] el x =p x +(vw x +ve)×(tt x )

[0015] Straight lines connect all EUs x and el x This generates a polygonal region of the ship's exhaust plume.

[0016] As the preferred technical scheme of the present application, S2 identifies all or part of the pixels located in the polygon area of the ship exhaust plume as the ship exhaust plume pixels, and the number of the pixels is n e ; the adjacent pixels of the ship exhaust plume pixels in the upwind direction are identified as the background pixels, and the number of the pixels is n b .

[0017] As the preferred technical scheme of the present application, S3 calculates the ship exhaust plume and the background NO2 concentration, the exhaust plume NO2 concentration C e is the average value of the NO2 concentration C of all the ship exhaust plume pixels, and the background NO2 concentration C b is the average value of the NO2 concentration C of all the background pixels.

[0018] As the preferred technical scheme of the present application, in the S4 calculation of the NO2 emission amount of the ship per unit time, the ship NO2 emission amount = (C e -C b ) × n e × r 2 .

[0019] As the preferred technical scheme of the present application, in the S4 calculation of the NO2 emission amount of the ship per unit time, the effective exhaust plume diffusion time length is the difference between the maximum t x and the minimum t x , and the maximum t x - the minimum t x ≤ i.

[0020] As the preferred technical scheme of the present application, in the S4 calculation of the NO2 emission amount of the ship per unit time, the NO2 emission amount of the ship per unit time = the ship NO2 emission amount / effective exhaust plume diffusion time length.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] In the scheme of the present application:

[0023] 1. By acquiring satellite remote sensing images and ship AIS data, according to the orbit of the atmospheric pollution remote sensing satellite, a grid format atmospheric pollution remote sensing image is acquired, the resolution is r, that is, the coverage area of each pixel is r 2 , the value of each pixel represents the NO2 column concentration C in the pixel coverage range, the shooting time t of the image is recorded, and a specific range a covering the ship route is manually set to effectively crop the image.

[0024] 2. By identifying the ship exhaust plume and the background pixels, p xPosition [t-i, t] time range average wind speed and wind direction data vw obtained by meteorological monitoring satellite x , set the air mass expansion speed v e , v e It can be a constant, also can be an arbitrary air mass expansion speed variable expansion speed changes with time, using atmospheric pollution remote sensing satellite ground NO2 concentration monitoring data, combined with real-time ship identity and positioning AIS data, realize from top to bottom ship atmospheric pollutant emission monitoring;

[0025] 3. By calculating the NO2 emission of the ship per unit time, the NO2 emission of the ship = (C e -C b )×n e ×r 2 , the effective exhaust plume diffusion time is the difference between the minimum t x And the maximum t x , the maximum t x - Minimum t x ≤i, the NO2 emission of the ship per unit time = the NO2 emission of the ship / effective exhaust plume diffusion time, and the NO2 emission can be effectively calculated. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 A flow chart of a ship NO2 emission calculation method based on satellite remote sensing of the present application;

[0027] Fig. 2 A schematic diagram of the present application for identifying ship exhaust plume and background pixels based on ship AIS data and wind speed and direction data. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are a specific embodiment of the present application, and are not limited to all embodiments.

[0029] Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but only represents some embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0030] It should be noted that the embodiments in the present application and the features and technical solutions in the embodiments can be combined with each other without conflict, and it should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0031] like Figs. 1-2 A method for calculating NO2 emissions from ships based on satellite remote sensing includes S1 acquiring satellite remote sensing images and ship AIS data, acquiring raster-format atmospheric pollution remote sensing images through the orbit of an atmospheric pollution remote sensing satellite, and filtering ship AIS data within the spatial range [ti,t] of all ship AIS data;

[0032] After acquiring satellite remote sensing images and ship AIS data, S2 identifies ship exhaust plume and background pixels, with pixels within the polygonal area of ​​the ship exhaust plume being used as ship exhaust plume pixels.

[0033] S3 calculates the ship's exhaust plume and background NO2 concentration;

[0034] After obtaining the ship's exhaust plume and background NO2 concentration, S4 calculates the ship's NO2 emissions per unit time.

[0035] As a preferred technical solution of this application, step S1 acquires satellite remote sensing images and ship AIS data. Through the orbit of an atmospheric pollution remote sensing satellite, it acquires raster-format atmospheric pollution remote sensing images with a resolution of r, meaning each pixel covers an area of ​​r. 2 The value of each pixel represents the NO2 column concentration C within the pixel's coverage area. The image was captured at the time t. A specific range a covering the ship's route was manually set, and the image was cropped.

[0036] As a preferred technical solution of this application, during the image cropping process, a tail gas diffusion duration i is set, and ship AIS data within the spatial range [ti,t] and time range of all ship AIS data are filtered, i.e., a series of [p] x ,t x Dataset, t x Within the time range [ti,t], p x Including longitude and latitude, for the ship's t x The position corresponding to the given time.

[0037] As a preferred technical solution of this application, the S2 identifies the ship's exhaust plume and background pixels to obtain p. x Average wind speed and direction data vw obtained from meteorological monitoring satellites within the time range of location [ti,t]. x Set the gas mass expansion rate v e v e It can be a constant or an arbitrary variable representing the expansion rate of the air mass, which varies with time.

[0038] As a preferred technical solution of the present application, the S2 calculates the upper boundary node eu of the ship exhaust gas diffusion position x and the lower boundary node el x ;

[0039] eu x = p x + (vw x - ve) x (t - t x )

[0040] el x = p x + (vw x + ve) x (t - t x )

[0041] Connecting all eu x and el x with straight lines generates a ship exhaust gas plume belt polygon area.

[0042] As a preferred technical solution of the present application, the S2 identifies all or part of the pixels located in the ship exhaust gas plume belt polygon area as ship exhaust gas plume belt pixels, and counts the number of pixels n e ; the adjacent pixels in the upwind direction in the ship exhaust gas plume belt pixels are background pixels, and the number of pixels n b is counted, the S3 calculates the ship exhaust gas plume belt and the background NO2 concentration, the exhaust gas plume belt NO2 concentration C e is the average value of the NO2 concentration C of all ship exhaust gas plume belt pixels, and the background NO2 concentration C b is the average value of the NO2 concentration C of all background pixels.

[0043] As a preferred technical solution of the present application, the S4 measures the ship's NO2 emission in unit time, wherein the ship's NO2 emission = (C e - C b ) x n e x r 2 , the effective exhaust belt diffusion duration in the S4 measuring the ship's NO2 emission in unit time is the difference between the maximum t x and the minimum t x , the maximum t x - the minimum t x ≤ i, and the ship's NO2 emission in unit time = the ship's NO2 emission / the effective exhaust belt diffusion duration.

[0044] Working steps: S1 obtains satellite remote sensing images and ship AIS data, obtains grid format atmospheric pollution remote sensing images according to the orbit of the atmospheric pollution remote sensing satellite, and the resolution is r, that is, the coverage area of each pixel is r 2Each pixel's value represents the NO2 column concentration C within its coverage area. The image capture time is recorded as t. A specific range a covering the ship's route is manually set. The image is cropped, and the exhaust gas diffusion duration i is set. Ship AIS data within the spatial range [ti,t] of all ship AIS data is filtered from all data, resulting in a series of [p...]... x ,t x Dataset, t x Within the time range [ti,t], p x Including longitude and latitude, for the ship's t x The position corresponding to the given time.

[0045] S2 identifies ship exhaust plumes and background pixels, obtaining p x Average wind speed and direction data vw obtained from meteorological monitoring satellites within the time range of location [ti,t]. x Set the gas mass expansion rate v e v e It can be a constant or any variable representing the gas mass expansion rate (expansion rate varies with time). S2 calculates the upper boundary node eu of the ship's exhaust gas diffusion location. x and lower boundary node el x ;

[0046] eu x =p x +(vw x -ve)×(tt x )

[0047] el x =p x +(vw x +ve)×(tt x )

[0048] Straight lines connect all EUs x and el x Generate a polygonal region for the ship's exhaust plume, identify all or part of the pixels located within this polygonal region as the ship's exhaust plume pixels, and count the number of pixels as n. e The adjacent pixels in the upwind direction of the ship's exhaust plume are used as background pixels, and the number of pixels n is counted. b .

[0049] S3 calculates the NO2 concentration in the ship's exhaust plume and background NO2 concentration, and the NO2 concentration in the exhaust plume is C. e The average NO2 concentration C for all ship exhaust plumes is given, along with the background NO2 concentration C. b This represents the average NO2 concentration C of all background pixels.

[0050] S4 calculates the NO2 emission of the ship per unit time, and the NO2 emission of the ship = (C e -C b ) × n e × r 2 , the effective exhaust gas diffusion duration is the difference between the maximum t x and the minimum t x , the maximum t x - the minimum t x ≤ i, and the NO2 emission of the ship per unit time = the NO2 emission of the ship / the effective exhaust gas diffusion duration.

[0051] The above examples are only used to illustrate the present application and are not intended to limit the technical solutions described in the present application. Although the present application has been described in detail with reference to the above embodiments, the present application is not limited to the above specific embodiments. Therefore, any modification or equivalent replacement of the present application; and all technical solutions and improvements without departing from the spirit and scope of the application are all included in the scope of the claims of the present application.

Claims

1. A satellite remote sensing-based method for measuring and calculating NO2 emissions of a ship, characterized in that, Comprise the following steps: S1 obtains satellite remote sensing image and ship AIS data, obtains grid format atmospheric pollution remote sensing image through the orbit of atmospheric pollution remote sensing satellite, and selects the ship AIS data in the spatial range a and the time range [t-i, t] in all ship AIS data; S2 after obtaining satellite remote sensing image and ship AIS data, identify ship exhaust plume and background pixels, wherein the pixels in the ship exhaust plume polygon region are used as ship exhaust plume pixels; S3 calculate the concentration of NO2 in ship exhaust plume and background; S4 after obtaining the concentration of NO2 in ship exhaust plume and background, measure the NO2 emission of ship per unit time; The S1 acquires satellite remote sensing images and ship AIS data, acquires grid format atmospheric pollution remote sensing images through the orbit of the atmospheric pollution remote sensing satellite, and the resolution is r, that is, the coverage area of each pixel is r 2 The value of each pixel represents the NO2 column concentration C in the pixel coverage range, the shooting time t of the image is recorded, a specific range a covering the ship route is artificially set, and the image is cropped; The tail gas belt diffusion duration i is set in the process of image clipping, the ship AIS data in the space range a and the time range [t-i, t] is screened from all ship AIS data, that is, a series of [p x ,t x ] data sets, t x In the time range [t-i, t], p x Include longitude and latitude, which correspond to the position of the ship t x Instantaneous The S2 identifies the ship exhaust plume and background pixels to obtain p x The average wind speed and direction data vw obtained by the meteorological monitoring satellite in the position [t-i, t] time range x The air mass expansion speed v e The v e It can be a constant, or an arbitrary air mass expansion speed variable expansion speed changes over time; The S2 calculates the upper boundary node eu of the ship exhaust gas diffusion position x and the lower boundary node el x ; eu x = p x + (vw x - v e ) x (t - t x ); el x = p x + (vw x + v e ) x (t - t x ); straight line connecting all eus x and el x generating a polygonal area of the ship exhaust plume.

2. The method according to claim 1, wherein, The S2 identifies all or part of the pixels located in the polygon area of the ship exhaust plume tail as the ship exhaust plume tail pixels, and counts the number of the pixels as n e ; the adjacent pixels of the ship exhaust plume tail pixels located in the upwind direction as the background pixels, and counts the number of the pixels as n b .

3. The method according to claim 1, wherein, S3 calculates the ship exhaust plume band and background NO2 concentrations, the exhaust plume band NO2 concentration C e is the average of all ship exhaust plume band pixel NO2 concentrations C b is the average of all background pixel NO2 concentrations C.

4. The method according to claim 1, wherein, The S4 calculates the NO2 emission amount of the ship per unit time, wherein the NO2 emission amount of the ship = (C e -C b ) × n e × r 2 , wherein n e is the pixel number of the pixel of the NO2 concentration of the exhaust plume of the ship, C e is the pixel number of the pixel of the NO2 concentration of the exhaust plume of the ship, and C b is the background NO2 concentration.

5. The method according to claim 1, wherein, The S4 calculates the effective exhaust gas diffusion duration of the ship unit time NO2emission amount as the difference between the maximum t x and the minimum t x The maximum t x - the minimum t x ≤ i.

6. The method according to claim 1, wherein, In the S4, the NO2 emission of ship per unit time=ship NO2 emission / effective exhaust belt diffusion duration.

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