Ground-based Rayleigh laser radar density measurement uncertainty evaluation method and system

Abstract

The invention provides a ground-based Rayleigh laser radar density measurement uncertainty evaluation method and system. The method comprises the following steps: determining a measurement inversion model; determining parameters of detection equipment; determining a measurement uncertainty source; a first uncertainty and a sensitivity coefficient introduced by photon noise of a detection point, a second uncertainty and a sensitivity coefficient introduced by photon noise of a reference point, a third uncertainty and a sensitivity coefficient introduced by background noise, and a fourth uncertainty and a sensitivity coefficient introduced by dead time of the detection point are calculated respectively; the fifth uncertainty and the sensitivity coefficient are introduced by the reference point dead time; the sixth uncertainty and the sensitivity coefficient are introduced by the reference density; calculating and obtaining first to sixth measurement uncertainty components respectively; the standard uncertainty is synthesized; and calculating to obtain the expansion uncertainty. By applying the technical scheme of the invention, the technical problem that the density measurement uncertainty of the ground-based Rayleigh laser radar is difficult to evaluate effectively in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of metrology testing and environmental detection technology, and in particular to a method and system for evaluating the uncertainty of density measurement of a ground-based Rayleigh laser radar. Background Art

[0002] With the increasing demand for understanding the high-altitude atmospheric environment and evaluating the dispersion of detection data, uncertainty assessment of detection data has become a crucial link. Measurement uncertainty can characterize the dispersion and credibility of measurement results, and indirectly reflect the quality of detection activities. Ground-based Rayleigh LiDAR can detect environmental parameters such as atmospheric density, temperature, and wind field at an altitude of 30km to 80km from the ground. It is an important detection method for understanding the near-space environment. Therefore, the assessment of its measurement uncertainty is particularly important for the quality control of data and detection activities. The GUM measurement uncertainty assessment method is relatively simple to calculate, and it is easy to use software calculations for batch data, but there are certain subjective factors, and the sensitivity coefficient is very difficult to solve.

[0003] At present, there is no effective evaluation method for the uncertainty assessment of ground-based lidar density measurement, and the knowledge of the dispersion of measurement results is insufficient. The ground-based Rayleigh lidar detection system has complex components and numerous equipment parameters, which makes it difficult to use digital twins. It is difficult to evaluate the measurement uncertainty when there are only a few basic parameters. Since the sensitivity coefficient contains many partial derivatives of composite functions, it needs to be obtained through approximate calculation and derivation, which makes the evaluation calculation very difficult. Summary of the invention

[0004] The present invention provides a method and system for evaluating the uncertainty of density measurement of a ground-based Rayleigh laser radar, which can solve the technical problem in the prior art that it is difficult to effectively evaluate the uncertainty of density measurement of a ground-based Rayleigh laser radar.

[0005] The present invention provides a method for evaluating the uncertainty of density measurement by a ground-based Rayleigh laser radar. The method comprises the following steps: clarifying a measurement inversion model; clarifying detection equipment parameters; clarifying the source of measurement uncertainty according to the measurement inversion model; based on the detection equipment parameters and the source of measurement uncertainty, respectively calculating and acquiring a first uncertainty and a first sensitivity coefficient introduced by detection point photon noise, a second uncertainty and a second sensitivity coefficient introduced by reference point photon noise, a third uncertainty and a third sensitivity coefficient introduced by background noise, a fourth uncertainty and a fourth sensitivity coefficient introduced by detection point dead time, a fifth uncertainty and a fifth sensitivity coefficient introduced by reference point dead time, and a sixth uncertainty and a sixth sensitivity coefficient introduced by reference density; calculating and acquiring a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by detection point photon noise, and obtaining a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by reference point photon noise. The second measurement uncertainty component is obtained by calculating the second uncertainty and the second sensitivity coefficient introduced by the noise, the third measurement uncertainty component is obtained by calculating the third uncertainty and the third sensitivity coefficient introduced by the background noise, the fourth measurement uncertainty component is obtained by calculating the fourth uncertainty introduced by the dead time of the detection point and the fourth sensitivity coefficient, the fifth measurement uncertainty component is obtained by calculating the fifth uncertainty introduced by the dead time of the reference point and the fifth sensitivity coefficient, and the sixth measurement uncertainty component is obtained by calculating the sixth uncertainty introduced by the reference density and the sixth sensitivity coefficient; the standard uncertainty is synthesized according to the first measurement uncertainty component, the second measurement uncertainty component, the third measurement uncertainty component, the fourth measurement uncertainty component, the fifth measurement uncertainty component and the sixth measurement uncertainty component; the expanded uncertainty is calculated according to the standard uncertainty, and the uncertainty assessment of ground-based Rayleigh lidar density measurement is completed.

[0006] Furthermore, the measurement inversion model is Among them, n A (z) is the atmospheric density at the height z of the detection point, n A (z0) is the atmospheric density at the reference point z0, z is the height of the detection point, z0 is the reference height of atmospheric Rayleigh scattering, N B (z) is the echo signal strength at the detection point z height after saturation correction and background noise correction, N B (z0) is the echo signal strength at the reference point z0 after saturation correction and background noise correction.

[0007] Further, calculating and obtaining the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise specifically includes: calculating the number of photons N after saturation correction at the detection point c (z); Photon number N after saturation correction based on the detection point c(z) and the background light photon number B are used to calculate the photon number N after background noise correction at the detection point. B (z); according to the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the detection point R (z) Calculate and obtain the first uncertainty introduced by the photon noise at the detection point; according to the number of photons N after saturation correction at the detection point c (z), the number of photons after background noise correction at the detection point N B (z), the number of photons N of the original Rayleigh scattered echo signal received by the lidar at the detection point R (z) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the first sensitivity coefficient.

[0008] Further, calculating and obtaining the second uncertainty and the second sensitivity coefficient introduced by the reference point photon noise specifically includes: calculating the number of photons N after the reference point saturation correction c (z0); the number of photons N after saturation correction based on the reference point c (z0) and the background light photon number B are used to calculate the photon number N after background noise correction at the reference point. B (z0); according to the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) Calculate and obtain the second uncertainty introduced by the reference point photon noise; according to the photon number N after the reference point saturation correction c (z0), the number of photons after background noise correction at the reference point N B (z0), the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the second sensitivity coefficient.

[0009] Further, calculating and obtaining the third uncertainty and the third sensitivity coefficient introduced by the background noise specifically includes: calculating and obtaining the third uncertainty introduced by the background noise according to the number of background light photons; calculating the third uncertainty introduced by the background noise according to the number of photons N after the background noise correction at the detection point B (z), the number of photons after background noise correction at the reference point N B (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the third sensitivity coefficient.

[0010] Further, calculating and obtaining the fourth uncertainty and the fourth sensitivity coefficient introduced by the dead time of the detection point specifically includes: calculating and obtaining the fourth uncertainty introduced by the dead time of the detection point according to the formula u4(τ)=0.01ns; calculating the photon number N after the background noise correction of the detection point according to the photon number N B (z), the number of photons after saturation correction at the detection point N c(z), atmospheric density n at the height z of the detection point A The fourth sensitivity coefficient is calculated based on (z), the speed of light, the height resolution of the Rayleigh LiDAR and the accumulated pulse number of the Rayleigh LiDAR.

[0011] Further, calculating and obtaining the fifth uncertainty and the fifth sensitivity coefficient introduced by the reference point dead time specifically includes: calculating and obtaining the fifth uncertainty introduced by the reference point dead time according to the formula u5(τ)=0.01ns; calculating the photon number N after the reference point background noise correction B (z0), the number of photons after reference point saturation correction N c (z0), atmospheric density n at the height z of the detection point A The fifth sensitivity coefficient is calculated based on (z), speed of light, Rayleigh lidar height resolution and the accumulated pulse number of Rayleigh lidar.

[0012] Furthermore, calculating and obtaining the sixth uncertainty and the sixth sensitivity coefficient introduced by the reference density specifically includes: if the reference density adopts the standard atmosphere, then the sixth uncertainty u6(n A (z0))=0, if the atmospheric density in-situ detection method is used, then the sixth uncertainty u6(n A (z0)) is the measurement uncertainty value evaluated by in-situ detection; according to the atmospheric density n at the detection point z A (z) and the atmospheric density n at the reference point z0 A (z0) Calculate and obtain the sixth sensitivity coefficient.

[0013] Furthermore, the standard uncertainty u c (n A ) can be based on Calculate and obtain, where u1 is the first measurement uncertainty component, u2 is the second measurement uncertainty component, u3 is the third measurement uncertainty component, u4 is the fourth measurement uncertainty component, u5 is the fifth measurement uncertainty component, u6 is the sixth measurement uncertainty component, c1 is the first sensitivity coefficient, c2 is the second sensitivity coefficient, c3 is the third sensitivity coefficient, c4 is the fourth sensitivity coefficient, c5 is the fifth sensitivity coefficient, c6 is the sixth sensitivity coefficient, u1(N R (z)) is the first uncertainty, u2(N R (z0)) is the second uncertainty, u3(B) is the third uncertainty, u4(τ) is the fourth uncertainty, u5(τ) is the fifth uncertainty, u6(n A (z0)) is the sixth uncertainty.

[0014] According to another aspect of the present invention, a ground-based Rayleigh laser radar density measurement uncertainty assessment system is provided, and the ground-based Rayleigh laser radar density measurement uncertainty assessment system uses the ground-based Rayleigh laser radar density measurement uncertainty assessment method as described above to perform ground-based Rayleigh laser radar density measurement uncertainty assessment.

[0015] By applying the technical solution of the present invention, a method for evaluating the uncertainty of density measurement of a ground-based Rayleigh laser radar is provided. The method takes the GUM measurement uncertainty evaluation method as the core, and forms a complete mathematical model for evaluating the uncertainty of measurement, a sensitivity coefficient calculation formula, a calculation process, etc. for the density detection process and detection system characteristics of the ground-based Rayleigh laser radar. After clarifying the ground-based laser radar density measurement inversion model and main parameters, the standard uncertainty is synthesized by substituting the measurement uncertainty model, the measurement uncertainty component calculation formula, the sensitivity coefficient calculation formula, and other steps, and the expanded uncertainty is calculated. Compared with the prior art, the method for evaluating the uncertainty of density measurement of the ground-based Rayleigh laser radar provided by the present invention can accurately and efficiently evaluate the measurement uncertainty of the ground-based Rayleigh laser radar during high-altitude detection. The calculation process is clear and simple, and it is suitable for situations where the parameters of the ground-based laser radar equipment are not fully mastered; in addition, the present invention has low calculation difficulty, is easy to implement software calculation, and is suitable for situations where the amount of detection data is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A flow chart of a method for evaluating uncertainty in density measurement of a ground-based Rayleigh lidar provided according to a specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0018] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0021] like Figure 1As shown, according to a specific embodiment of the present invention, a method for evaluating the uncertainty of density measurement by a ground-based Rayleigh laser radar is provided, and the method for evaluating the uncertainty of density measurement by a ground-based Rayleigh laser radar comprises: clarifying a measurement inversion model; clarifying detection equipment parameters; clarifying the source of measurement uncertainty according to the measurement inversion model; based on the detection equipment parameters and the source of measurement uncertainty, respectively calculating and obtaining a first uncertainty and a first sensitivity coefficient introduced by detection point photon noise, a second uncertainty and a second sensitivity coefficient introduced by reference point photon noise, a third uncertainty and a third sensitivity coefficient introduced by background noise, a fourth uncertainty and a fourth sensitivity coefficient introduced by detection point dead time, a fifth uncertainty and a fifth sensitivity coefficient introduced by reference point dead time, and a sixth uncertainty and a sixth sensitivity coefficient introduced by reference density; calculating and obtaining a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by detection point photon noise, and obtaining a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by detection point photon noise, and obtaining a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by detection point photon noise, and obtaining a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by detection point photon noise, and obtaining a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by detection point photon noise, and obtaining a first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by reference ... The second measurement uncertainty component is obtained by calculating the second uncertainty introduced by the reference point photon noise and the second sensitivity coefficient, the third measurement uncertainty component is obtained by calculating the third uncertainty introduced by the background noise and the third sensitivity coefficient, the fourth measurement uncertainty component is obtained by calculating the fourth uncertainty introduced by the detection point dead time and the fourth sensitivity coefficient, the fifth measurement uncertainty component is obtained by calculating the fifth uncertainty introduced by the reference point dead time and the fifth sensitivity coefficient, and the sixth measurement uncertainty component is obtained by calculating the sixth uncertainty introduced by the reference density and the sixth sensitivity coefficient; the standard uncertainty is synthesized according to the first measurement uncertainty component, the second measurement uncertainty component, the third measurement uncertainty component, the fourth measurement uncertainty component, the fifth measurement uncertainty component and the sixth measurement uncertainty component; the expanded uncertainty is calculated according to the standard uncertainty, and the uncertainty assessment of ground-based Rayleigh lidar density measurement is completed.

[0022] By applying this configuration, a method for evaluating the uncertainty of density measurement of a ground-based Rayleigh laser radar is provided. The method takes the GUM measurement uncertainty evaluation method as the core, and forms a complete mathematical model for evaluating the uncertainty of measurement, a sensitivity coefficient calculation formula, a calculation process, etc. for the density detection process and detection system characteristics of the ground-based Rayleigh laser radar. After clarifying the ground-based laser radar density measurement inversion model and main parameters, the standard uncertainty is synthesized by substituting the measurement uncertainty model, the measurement uncertainty component calculation formula, the sensitivity coefficient calculation formula, and other steps, and the expanded uncertainty is calculated. Compared with the prior art, the method for evaluating the uncertainty of density measurement of the ground-based Rayleigh laser radar provided by the present invention can accurately and efficiently evaluate the measurement uncertainty of the ground-based Rayleigh laser radar during high-altitude detection. The calculation process is clear and simple, and it is suitable for situations where the parameters of the ground-based laser radar equipment are not fully mastered; in addition, the present invention has low calculation difficulty, is easy to implement software calculation, and is suitable for situations where the amount of detection data is large.

[0023] Specifically, in order to realize the uncertainty assessment of ground-based Rayleigh lidar density measurement, it is necessary to first clarify the measurement inversion model. In the present invention, the measurement inversion model is Among them, n A (z) is the atmospheric density at the height z of the detection point, n A (z0) is the atmospheric density at the reference point z0, z is the height of the detection point, z0 is the reference height of atmospheric Rayleigh scattering, N B (z) is the echo signal strength at the detection point z height after saturation correction and background noise correction, N B (z0) is the echo signal strength at the reference point z0 after saturation correction and background noise correction.

[0024] After obtaining the measurement inversion model, the detection equipment parameters can be determined. In the present invention, the detection equipment parameters include the Rayleigh laser radar detector dead time τ, the Rayleigh laser radar height resolution δz, the Rayleigh laser radar accumulated pulse number L, the speed of light c, the atmospheric density n at the detection height A (z) and the atmospheric density n at the reference altitude A (z0).

[0025] Furthermore, after the detection equipment parameters are determined, the sources of measurement uncertainty can be determined based on the measurement inversion model. In the present invention, the sources of measurement uncertainty include detection point photon noise, reference point photon noise, background noise, detection dead time, reference dead time and reference density.

[0026] After clarifying the sources of measurement uncertainty, the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise, the second uncertainty and the second sensitivity coefficient introduced by the reference point photon noise, the third uncertainty and the third sensitivity coefficient introduced by the background noise, the fourth uncertainty and the fourth sensitivity coefficient introduced by the detection point dead time, the fifth uncertainty and the fifth sensitivity coefficient introduced by the reference point dead time, and the sixth uncertainty and the sixth sensitivity coefficient introduced by the reference density can be calculated based on the detection equipment parameters and the sources of measurement uncertainty. The first measurement uncertainty component is obtained by calculation, the second measurement uncertainty component is obtained by calculation according to the second uncertainty introduced by the reference point photon noise and the second sensitivity coefficient, the third measurement uncertainty component is obtained by calculation according to the third uncertainty introduced by the background noise and the third sensitivity coefficient, the fourth measurement uncertainty component is obtained by calculation according to the fourth uncertainty introduced by the detection point dead time and the fourth sensitivity coefficient, the fifth measurement uncertainty component is obtained by calculation according to the fifth uncertainty introduced by the reference point dead time and the fifth sensitivity coefficient, and the sixth measurement uncertainty component is obtained by calculation according to the sixth uncertainty introduced by the reference density and the sixth sensitivity coefficient. The acquisition process of the six measurement uncertainty components is described in detail below.

[0027] In the present invention, calculating and obtaining the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise specifically includes: calculating the number of photons N after saturation correction at the detection point c (z); Photon number N after saturation correction based on the detection point c (z) and the background light photon number B are used to calculate the photon number N after background noise correction at the detection point. B (z); according to the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the detection point R (z) Calculate and obtain the first uncertainty u1(N) introduced by the photon noise at the detection point R (z)); according to the number of photons N after saturation correction at the detection point c (z), the number of photons after background noise correction at the detection point N B (z), the number of photons N of the original Rayleigh scattered echo signal received by the lidar at the detection point R (z) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the first sensitivity coefficient c1. After obtaining the first uncertainty u1(N R (z)) and the first sensitivity coefficient c1, according to u1=c1u1(N R (z)) Calculate and obtain the first measurement uncertainty component u1.

[0028] Calculating and obtaining the second uncertainty and the second sensitivity coefficient introduced by the reference point photon noise specifically includes: calculating the number of photons N after the reference point saturation correction c (z0); the number of photons N after saturation correction based on the reference point c (z0) and the background light photon number B are used to calculate the photon number N after background noise correction at the reference point. B (z0); according to the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) Calculate the second uncertainty u2(N) introduced by the reference point photon noise R (z0)); according to the photon number N after saturation correction at the reference point c (z0), the number of photons after background noise correction at the reference point N B (z0), the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the second sensitivity coefficient c2. After obtaining the first uncertainty u2 (N R (z0)) and the first sensitivity coefficient c2, according to u2 = c2u2 (N R (z0)) calculates and obtains the second measurement uncertainty component u2.

[0029] The third uncertainty and the third sensitivity coefficient introduced by the background noise are calculated and obtained specifically including: calculating and obtaining the third uncertainty u3(B) introduced by the background noise according to the number of background light photons; calculating and obtaining the third uncertainty u3(B) introduced by the background noise according to the number of photons N corrected for the background noise at the detection point ... B (z), the number of photons after background noise correction at the reference point N B (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the third sensitivity coefficient c3. After obtaining the third uncertainty u3(B) and the third sensitivity coefficient c3, calculate and obtain the third measurement uncertainty component u3 according to u3=c3u3(B).

[0030] Calculating and obtaining the fourth uncertainty and the fourth sensitivity coefficient introduced by the dead time of the detection point specifically includes: calculating and obtaining the fourth uncertainty introduced by the dead time of the detection point according to the formula u4(τ)=0.01ns; calculating and obtaining the fourth uncertainty introduced by the dead time of the detection point according to the photon number N after the background noise correction of the detection point B (z), the number of photons after saturation correction at the detection point N c (z), atmospheric density n at the height z of the detection point A(z), light speed, Rayleigh laser radar height resolution and Rayleigh laser radar accumulated pulse number are used to calculate the fourth sensitivity coefficient. After obtaining the fourth uncertainty u4(τ) and the fourth sensitivity coefficient c4, the fourth measurement uncertainty component u4 is calculated according to u4=c4u4(τ).

[0031] Calculating and obtaining the fifth uncertainty and the fifth sensitivity coefficient introduced by the reference point dead time specifically includes: calculating and obtaining the fifth uncertainty u5(τ) introduced by the reference point dead time according to the formula u5(τ)=0.01ns; calculating the photon number N after the reference point background noise correction B (z0), the number of photons after reference point saturation correction N c (z0), atmospheric density n at the height z of the detection point A (z), light speed, Rayleigh laser radar height resolution and Rayleigh laser radar accumulated pulse number are used to calculate the fifth sensitivity coefficient c5. After obtaining the fifth uncertainty u5(τ) and the fifth sensitivity coefficient c5, the fifth measurement uncertainty component u5 is calculated according to u5=c5u5(τ).

[0032] The calculation to obtain the sixth uncertainty and sixth sensitivity coefficient introduced by the reference density specifically includes: if the reference density adopts the standard atmosphere, then the sixth uncertainty u6(n A (z0))=0, if the atmospheric density in-situ detection method is used, then the sixth uncertainty u6(n A (z0)) is the measurement uncertainty value evaluated by in-situ detection; according to the atmospheric density n at the detection point z A (z) and the atmospheric density n at the reference point z0 A (z0) calculates and obtains the sixth sensitivity coefficient c6. After obtaining the sixth uncertainty u6 (n A (z0)) and the sixth sensitivity coefficient c6, according to u6=c6u6(n A (z0)) calculates and obtains the sixth measurement uncertainty component u6.

[0033] Further, after obtaining the six measurement uncertainty components, the standard uncertainty can be synthesized according to the first measurement uncertainty component, the second measurement uncertainty component, the third measurement uncertainty component, the fourth measurement uncertainty component, the fifth measurement uncertainty component and the sixth measurement uncertainty component. In the present invention, the standard uncertainty u c (n A ) can be based on Calculate and obtain, where u1 is the first measurement uncertainty component, u2 is the second measurement uncertainty component, u3 is the third measurement uncertainty component, u4 is the fourth measurement uncertainty component, u5 is the fifth measurement uncertainty component, u6 is the sixth measurement uncertainty component, c1 is the first sensitivity coefficient, c2 is the second sensitivity coefficient, c3 is the third sensitivity coefficient, c4 is the fourth sensitivity coefficient, c5 is the fifth sensitivity coefficient, c6 is the sixth sensitivity coefficient, u1(N R (z)) is the first uncertainty, u2(N R (z0)) is the second uncertainty, u3(B) is the third uncertainty, u4(τ) is the fourth uncertainty, u5(τ) is the fifth uncertainty, u6(n A (z0)) is the sixth uncertainty.

[0034] After obtaining the standard uncertainty, the expanded uncertainty can be calculated based on the standard uncertainty to complete the uncertainty assessment of ground-based Rayleigh lidar density measurement. In the present invention, the expanded uncertainty U can be calculated based on U=k·u c (n A (z)) is calculated, where k is the inclusion factor and u c (n A (z)) is the standard uncertainty.

[0035] According to another aspect of the present invention, a ground-based Rayleigh laser radar density measurement uncertainty assessment system is provided, which uses the ground-based Rayleigh laser radar density measurement uncertainty assessment method as described above to perform ground-based Rayleigh laser radar density measurement uncertainty assessment.

[0036] By applying this configuration, a ground-based Rayleigh laser radar density measurement uncertainty assessment system is provided. The system takes the GUM measurement uncertainty assessment method as the core, and forms a complete measurement uncertainty assessment mathematical model, sensitivity coefficient calculation formula, calculation process, etc. for the ground-based Rayleigh laser radar density detection process and detection system characteristics. After clarifying the ground-based laser radar density measurement inversion model and main parameters, the standard uncertainty is synthesized by substituting the measurement uncertainty model, measurement uncertainty component calculation formula, sensitivity coefficient calculation formula and other steps, and the expanded uncertainty is calculated. Compared with the prior art, the ground-based Rayleigh laser radar density measurement uncertainty assessment system provided by the present invention can accurately and efficiently assess the measurement uncertainty of the ground-based Rayleigh laser radar during high-altitude detection. The calculation process is clear and simple, and it is suitable for situations where the parameters of the ground-based laser radar equipment are not fully mastered; in addition, the present invention has low calculation difficulty, is easy to implement software calculation, and is suitable for situations where the amount of detection data is large.

[0037] In order to further understand the present invention, the following Figure 1 The uncertainty evaluation method of ground-based Rayleigh lidar density measurement provided by the present invention is described in detail.

[0038] like Figure 1 As shown, according to a specific embodiment of the present invention, a method for evaluating the uncertainty GUM of density measurement of a ground-based Rayleigh lidar is provided, and the method specifically includes the following steps.

[0039] Step 1: Define the measurement inversion model.

[0040] Rayleigh lidar density measurement uses the following measurement inversion model. The relative density is obtained by measuring the ratio of the number of echo photons at the detection point and the reference point. The density of the detection point can be obtained through the density value of the reference point.

[0041]

[0042] Among them, n A (z) is the atmospheric density at the height z of the detection point, n A (z0) is the atmospheric density at the reference point z0, z is the height of the detection point, z0 is the reference height of atmospheric Rayleigh scattering, N B (z) is the echo signal strength at the detection point z height after saturation correction and background noise correction, N B (z0) is the echo signal strength at the reference point z0 after saturation correction and background noise correction.

[0043] Step 2: Clarify the detection equipment parameters.

[0044] (2.1) Define the dead time τ of the Rayleigh lidar detector;

[0045] (2.2) Define the Rayleigh lidar height resolution δz;

[0046] (2.3) Specify the number of accumulated pulses L of the Rayleigh lidar;

[0047] (2.4) Specify the value of the speed of light c;

[0048] (2.5) Determine the atmospheric density n at the detection altitude A (z);

[0049] (2.6) Specify the atmospheric density n at the reference altitude A (z0).

[0050] Step three: Identify the sources of measurement uncertainty.

[0051] (3.1) Detection point photon noise;

[0052] (3.2) Reference point photon noise;

[0053] (3.3) Background noise;

[0054] (3.4) Detection dead time;

[0055] (3.5) Reference dead time;

[0056] (3.6) Reference density.

[0057] Step 4: Based on the detection equipment parameters and the sources of measurement uncertainty, respectively calculate and obtain the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise, the second uncertainty and the second sensitivity coefficient introduced by the reference point photon noise, the third uncertainty and the third sensitivity coefficient introduced by the background noise, the fourth uncertainty and the fourth sensitivity coefficient introduced by the detection point dead time, the fifth uncertainty and the fifth sensitivity coefficient introduced by the reference point dead time, and the sixth uncertainty and the sixth sensitivity coefficient introduced by the reference density; calculate and obtain the first measurement according to the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise The uncertainty component is obtained by calculating the second measurement uncertainty component according to the second uncertainty introduced by the reference point photon noise and the second sensitivity coefficient, the third measurement uncertainty component is obtained by calculating the third uncertainty introduced by the background noise and the third sensitivity coefficient, the fourth measurement uncertainty component is obtained by calculating the fourth uncertainty introduced by the detection point dead time and the fourth sensitivity coefficient, the fifth measurement uncertainty component is obtained by calculating the fifth uncertainty introduced by the reference point dead time and the fifth sensitivity coefficient, and the sixth measurement uncertainty component is obtained by calculating the sixth uncertainty introduced by the reference density and the sixth sensitivity coefficient.

[0058] 4.1) Calculate the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise, and obtain the first measurement uncertainty component according to the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise.

[0059] (4.1.1) Calculate the number of photons at the detection point after saturation correction.

[0060] The photon number N after saturation correction is calculated as follows: c (z).

[0061]

[0062] Among them, N R (z) is the number of photons of the Rayleigh scattering original echo signal received by the lidar at the detection point (z height), τ is the dead time, c is the speed of light, δz is the height resolution of the Rayleigh lidar, and L is the number of accumulated pulses of the Rayleigh lidar.

[0063] (4.1.2) According to the number of photons N after saturation correction at the detection point c(z) and the background light photon number B are used to calculate the photon number N after background noise correction at the detection point. B (z).

[0064] The number of photons N after background noise correction is calculated as follows: B (z).

[0065] N B (z) = N C (z)-B

[0066] Among them, N c (z) is the number of echo photons at the detection point (height z) after saturation correction, B is the number of background light photons, and z0 is the reference point height.

[0067] (4.1.3) According to the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the detection point R (z) Calculate and obtain the first uncertainty u1(N) introduced by the photon noise at the detection point R (z)).

[0068]

[0069] (4.1.4) The number of photons N after saturation correction based on the detection point c (z), the number of photons after background noise correction at the detection point N B (z), the number of photons N of the original Rayleigh scattered echo signal received by the lidar at the detection point R (z) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the first sensitivity coefficient c1.

[0070]

[0071] (4.1.5) Calculate the first measurement uncertainty component u1.

[0072] The first measurement uncertainty component u1 is calculated according to the following formula.

[0073] u1=c1u1(N R (z))

[0074] 4.2) Calculate the second uncertainty and the second sensitivity coefficient introduced by the reference point photon noise, and obtain the second measurement uncertainty component according to the second uncertainty and the second sensitivity coefficient introduced by the reference point photon noise.

[0075] (4.2.1) Calculate the number of photons after saturation correction at the reference point

[0076] The photon number N after saturation correction is calculated as follows: c (z0).

[0077]

[0078] Among them, N R (z0) is the number of photons of the Rayleigh scattering original echo signal received by the lidar at the reference point (z0 height), τ is the dead time, c is the speed of light, δz is the height resolution of the Rayleigh lidar, and L is the number of accumulated pulses of the Rayleigh lidar.

[0079] (4.2.2) The number of photons after saturation correction based on the reference point N c (z0) and the background light photon number B are used to calculate the photon number N after background noise correction at the reference point. B (z0).

[0080] N B (z0) = N C (z0)-B

[0081] Among them, N c (z0) is the number of echo photons at the reference point (height z0) after saturation correction, B is the number of background light photons, and z0 is the height of the reference point.

[0082] (4.2.3) According to the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) calculates and obtains the second uncertainty introduced by the reference point photon noise.

[0083]

[0084] (4.2.4) The number of photons N after saturation correction according to the reference point c (z0), the number of photons after background noise correction at the reference point N B (z0), the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the second sensitivity coefficient c2.

[0085]

[0086] (4.2.5) Calculate the second measurement uncertainty component u2.

[0087] u2=c2u2(N R (z0))

[0088] 4.3) Calculate the third uncertainty and the third sensitivity coefficient introduced by the background noise, and obtain the third measurement uncertainty component according to the third uncertainty and the third sensitivity coefficient introduced by the background noise.

[0089] (4.3.1) The third uncertainty u3(B) introduced by the background noise is obtained by calculating the number of background light photons.

[0090]

[0091] (4.3.2) The number of photons N after correction of background noise at the detection point B (z), the number of photons after background noise correction at the reference point N B (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the third sensitivity coefficient c3.

[0092]

[0093] (4.3.3) Calculate the third measurement uncertainty component u3.

[0094] u3=c3u3(B)

[0095] 4.4) Calculate the fourth uncertainty and the fourth sensitivity coefficient of the detection point introduced by the dead time of the detection point, and obtain the fourth measurement uncertainty component according to the fourth uncertainty and the fourth sensitivity coefficient introduced by the dead time of the detection point.

[0096] (4.4.1) According to the formula u4(τ)=0.01ns (nanoseconds), the fourth uncertainty u4(τ) introduced by the dead time of the detection point is calculated.

[0097] (4.4.2) The number of photons N after correction of background noise at the detection point B (z), the number of photons after saturation correction at the detection point N c (z), atmospheric density n at the height z of the detection point A The fourth sensitivity coefficient c4 is calculated by using the Rayleigh laser radar height resolution δz and the Rayleigh laser radar accumulated pulse number L.

[0098]

[0099] (4.4.3) Calculate the fourth measurement uncertainty component u4.

[0100] u4=c4u4(τ)

[0101] 4.5) Calculate the fifth uncertainty and the fifth sensitivity coefficient of the reference point introduced by the reference point dead time, and obtain the fifth measurement uncertainty component according to the fifth uncertainty and the fifth sensitivity coefficient introduced by the reference point dead time.

[0102] (4.5.1) According to the formula u5(τ)=0.01ns, the fifth uncertainty u5(τ) introduced by the reference point dead time is calculated.

[0103] (4.5.2) The number of photons N after correction based on the background noise of the reference point B (z0), the number of photons after reference point saturation correction N c (z0), atmospheric density n at the height z of the detection point A The fifth sensitivity coefficient c5 is calculated based on the Rayleigh LiDAR height resolution δz and the accumulated pulse number L of the Rayleigh LiDAR.

[0104]

[0105] (4.5.3) Calculate the fifth measurement uncertainty component u5.

[0106] The fifth measurement uncertainty component u5 is calculated according to the following formula:

[0107] u5=c5u5(τ)

[0108] 4.6) Calculate the sixth uncertainty and the sixth sensitivity coefficient introduced by the reference density, and obtain the sixth measurement uncertainty component according to the sixth uncertainty and the sixth sensitivity coefficient introduced by the reference density.

[0109] (4.6.1) If the reference density is the standard atmosphere, then the sixth uncertainty u6(n A (z0))=0, if the atmospheric density in-situ detection method is used, then the sixth uncertainty u6(n A (z0)) is the measurement uncertainty value evaluated by in-situ detection.

[0110] (4.6.2) According to the atmospheric density n at the detection point z A (z) and the atmospheric density n at the reference point z0 A (z0) Calculate and obtain the sixth sensitivity coefficient c6.

[0111]

[0112] (4.6.3) Calculate the sixth measurement uncertainty component u6.

[0113] u6=c6u6(n A (z0))

[0114] Step five: synthesize the standard uncertainty according to the first measurement uncertainty component, the second measurement uncertainty component, the third measurement uncertainty component, the fourth measurement uncertainty component, the fifth measurement uncertainty component and the sixth measurement uncertainty component.

[0115] The standard uncertainty u is synthesized according to the following formula c (n A).

[0116]

[0117] Wherein, u1 is the first measurement uncertainty component, u2 is the second measurement uncertainty component, u3 is the third measurement uncertainty component, u4 is the fourth measurement uncertainty component, u5 is the fifth measurement uncertainty component, u6 is the sixth measurement uncertainty component, c1 is the first sensitivity coefficient, c2 is the second sensitivity coefficient, c3 is the third sensitivity coefficient, c4 is the fourth sensitivity coefficient, c5 is the fifth sensitivity coefficient, c6 is the sixth sensitivity coefficient, u1(N R (z)) is the first uncertainty, u2(N R (z0)) is the second uncertainty, u3(B) is the third uncertainty, u4(τ) is the fourth uncertainty, u5(τ) is the fifth uncertainty, u6(n A (z0)) is the sixth uncertainty.

[0118] Step six: Obtain the expanded uncertainty based on the standard uncertainty calculation to complete the uncertainty assessment of ground-based Rayleigh lidar density measurement.

[0119] U=k·u c (n A (z))

[0120] Among them, k is the coverage factor, u c (n A (z)) is the standard uncertainty.

[0121] Infinite atmospheric density detections obey a normal distribution. Select the confidence probability according to Table 1 below and obtain the inclusion factor k.

[0122] Table 1 Confidence probability and coverage factor correspondence table

[0123] Confidence probability p 0.999 0.9973 0.99 0.954 0.95 0.90 0.683 0.6745 Inclusion factor k 3.3 3 2.58 2 1.96 1.645 1 0.5

[0124] In summary, the present invention provides a method for evaluating the uncertainty of density measurement of a ground-based Rayleigh laser radar. The method takes the GUM measurement uncertainty evaluation method as the core, and forms a complete mathematical model for evaluating the uncertainty of measurement, a sensitivity coefficient calculation formula, a calculation process, etc. for the density detection process and detection system characteristics of the ground-based Rayleigh laser radar. After clarifying the density measurement inversion model and main parameters of the ground-based laser radar, the standard uncertainty is synthesized by substituting the measurement uncertainty model, the measurement uncertainty component calculation formula, the sensitivity coefficient calculation formula, etc., and the expanded uncertainty is calculated. Compared with the prior art, the method for evaluating the uncertainty of density measurement of the ground-based Rayleigh laser radar provided by the present invention provides a measurement uncertainty evaluation process, a calculation formula, etc. for the working principle and characteristics of density detection of the ground-based laser radar, and can accurately and efficiently evaluate the measurement uncertainty of the ground-based Rayleigh laser radar during high-altitude detection. The calculation process is clear and simple, and is suitable for situations where the parameters of the ground-based laser radar equipment are not fully mastered; in addition, the present invention has low calculation difficulty, is easy to implement software calculation, and is suitable for situations where the amount of detection data is large.

[0125] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0126] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating uncertainty in density measurement using ground-based Rayleigh lidar, characterized in that: The uncertainty evaluation method of ground-based Rayleigh laser radar density measurement includes: Clarify the measurement inversion model; Specify the detection equipment parameters; According to the measurement inversion model, the sources of measurement uncertainty are clarified; Based on the detection equipment parameters and the measurement uncertainty sources, respectively calculate and obtain a first uncertainty and a first sensitivity coefficient introduced by the detection point photon noise, a second uncertainty and a second sensitivity coefficient introduced by the reference point photon noise, a third uncertainty and a third sensitivity coefficient introduced by the background noise, a fourth uncertainty and a fourth sensitivity coefficient introduced by the detection point dead time, a fifth uncertainty and a fifth sensitivity coefficient introduced by the reference point dead time, and a sixth uncertainty and a sixth sensitivity coefficient introduced by the reference density; A first measurement uncertainty component is obtained according to a first uncertainty introduced by the photon noise at the detection point and a first sensitivity coefficient, a second measurement uncertainty component is obtained according to a second uncertainty introduced by the photon noise at the reference point and a second sensitivity coefficient, a third measurement uncertainty component is obtained according to a third uncertainty introduced by the background noise and a third sensitivity coefficient, a fourth measurement uncertainty component is obtained according to a fourth uncertainty introduced by the dead time of the detection point and a fourth sensitivity coefficient, a fifth measurement uncertainty component is obtained according to a fifth uncertainty introduced by the dead time of the reference point and a fifth sensitivity coefficient, and a sixth measurement uncertainty component is obtained according to a sixth uncertainty introduced by the reference density and a sixth sensitivity coefficient; synthesizing a standard uncertainty according to the first measurement uncertainty component, the second measurement uncertainty component, the third measurement uncertainty component, the fourth measurement uncertainty component, the fifth measurement uncertainty component, and the sixth measurement uncertainty component; The expanded uncertainty is obtained based on the standard uncertainty calculation, and the uncertainty assessment of ground-based Rayleigh lidar density measurement is completed.

2. The uncertainty evaluation method for density measurement of ground-based Rayleigh laser radar according to claim 1 is characterized in that: The measurement inversion model is Among them, n A (z) is the atmospheric density at the height z of the detection point, n A (z0) is the atmospheric density at the reference point z0, z is the height of the detection point, z0 is the reference height of atmospheric Rayleigh scattering, N B (z) is the echo signal strength at the detection point z height after saturation correction and background noise correction, N B (z0) is the echo signal strength at the reference point z0 after saturation correction and background noise correction.

3. The uncertainty evaluation method for density measurement of ground-based Rayleigh laser radar according to claim 1 is characterized in that: Calculating and obtaining the first uncertainty and the first sensitivity coefficient introduced by the detection point photon noise specifically includes: Calculate the number of photons N after saturation correction at the detection point c (z); The number of photons N after saturation correction based on the detection point c (z) and the background light photon number B are used to calculate the photon number N after background noise correction at the detection point. B (z); According to the number of photons N of the original Rayleigh scattered echo signal received by the laser radar at the detection point R (z) calculating and obtaining a first uncertainty introduced by the photon noise at the detection point; According to the photon number N after saturation correction of the detection point c (z), the number of photons after background noise correction at the detection point N B (z), the number of photons N of the original Rayleigh scattered echo signal received by the lidar at the detection point R (z) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the first sensitivity coefficient.

4. The method for uncertainty assessment of density measurement by ground-based Rayleigh laser radar according to claim 3 is characterized in that: Calculating and obtaining the second uncertainty and the second sensitivity coefficient introduced by the reference point photon noise specifically includes: Calculate the number of photons N after saturation correction at the reference point c (z0); The number of photons N after saturation correction based on the reference point c (z0) and the background light photon number B are used to calculate the photon number N after background noise correction at the reference point. B (z0); According to the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) calculating and obtaining a second uncertainty introduced by the reference point photon noise; According to the reference point saturation corrected photon number N c (z0), the number of photons after background noise correction at the reference point N B (z0), the number of photons N of the original echo signal of Rayleigh scattering received by the laser radar at the reference point R (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the second sensitivity coefficient.

5. The method for evaluating uncertainty of density measurement by ground-based Rayleigh laser radar according to claim 4 is characterized in that: Calculating and obtaining the third uncertainty and the third sensitivity coefficient introduced by the background noise specifically includes: The third uncertainty introduced by the background noise is obtained by calculating the number of background light photons; The number of photons N after correction of background noise at the detection point B (z), the number of photons after background noise correction at the reference point N B (z0) and the atmospheric density n at the height z of the detection point A (z) Calculate and obtain the third sensitivity coefficient.

6. The method for uncertainty assessment of density measurement by ground-based Rayleigh laser radar according to claim 5, characterized in that: Calculating and obtaining the fourth uncertainty and the fourth sensitivity coefficient introduced by the dead time of the detection point specifically includes: The fourth uncertainty introduced by the dead time of the detection point is calculated according to the formula u4(τ)=0.01ns; The number of photons N after correction of background noise at the detection point B (z), the number of photons after saturation correction at the detection point N c (z), atmospheric density n at the height z of the detection point A The fourth sensitivity coefficient is calculated based on (z), the speed of light, the height resolution of the Rayleigh LiDAR and the accumulated pulse number of the Rayleigh LiDAR.

7. The method for uncertainty assessment of density measurement by ground-based Rayleigh laser radar according to claim 6, characterized in that: Calculating and obtaining the fifth uncertainty and the fifth sensitivity coefficient introduced by the reference point dead time specifically includes: The fifth uncertainty introduced by the reference point dead time is calculated according to the formula u5(τ)=0.01ns; The number of photons N after correction based on the background noise of the reference point B (z0), the number of photons after reference point saturation correction N c (z0), atmospheric density n at the height z of the detection point A The fifth sensitivity coefficient is calculated based on (z), speed of light, Rayleigh lidar height resolution and the accumulated pulse number of Rayleigh lidar.

8. The method for uncertainty assessment of density measurement by ground-based Rayleigh laser radar according to claim 7, characterized in that: Calculating and obtaining the sixth uncertainty and sixth sensitivity coefficient introduced by the reference density specifically includes: If the reference density is standard atmosphere, then the sixth uncertainty u6(n A (z0))=0, if the atmospheric density in-situ detection method is used, then the sixth uncertainty u6(n A (z0)) is the measurement uncertainty value evaluated by in-situ detection; According to the atmospheric density n at the height z of the detection point A (z) and the atmospheric density n at the reference point z0 A (z0) Calculate and obtain the sixth sensitivity coefficient.

9. The method for evaluating uncertainty of density measurement by ground-based Rayleigh laser radar according to claim 8, characterized in that: The standard uncertainty u c (n A ) can be based on Calculate and obtain, where u1 is the first measurement uncertainty component, u2 is the second measurement uncertainty component, u3 is the third measurement uncertainty component, u4 is the fourth measurement uncertainty component, u5 is the fifth measurement uncertainty component, u6 is the sixth measurement uncertainty component, c1 is the first sensitivity coefficient, c2 is the second sensitivity coefficient, c3 is the third sensitivity coefficient, c4 is the fourth sensitivity coefficient, c5 is the fifth sensitivity coefficient, c6 is the sixth sensitivity coefficient, u1(N R (z)) is the first uncertainty, u2(N R (z0)) is the second uncertainty, u3(B) is the third uncertainty, u4(τ) is the fourth uncertainty, u5(τ) is the fifth uncertainty, u6(n A (z0)) is the sixth uncertainty.

10. A ground-based Rayleigh laser radar density measurement uncertainty assessment system, characterized in that: The ground-based Rayleigh laser radar density measurement uncertainty assessment system uses the ground-based Rayleigh laser radar density measurement uncertainty assessment method as described in claims 1 to 9 to perform ground-based Rayleigh laser radar density measurement uncertainty assessment.

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