A shore-based fixed multi-angle multi-spectral water quality detection method

Abstract

The application discloses a kind of shore-based fixed multi-angle multispectral water quality detection methods, including in the target water body shore fixedly setting multispectral imaging equipment and contact type water quality detection equipment, the position of multispectral imaging equipment and contact type water quality detection equipment keeps not displacement during water quality detection;By changing the observation angle of the multispectral imaging equipment, multispectral imaging is carried out on the water body area located at different spatial positions, corresponding multispectral image data is obtained, and imaging geometric parameters corresponding to the multispectral image data are obtained.The application keeps the equipment position from displacement during detection by using shore-based fixed multispectral imaging equipment, ensures the spatial reference consistency of multi-temporal, multi-angle water quality detection data, and is beneficial to long-term continuous monitoring and result comparison and analysis.

Description

Technical Field

[0001] This invention relates to the field of water environment monitoring and pollution source tracing technology, specifically to a shore-based fixed multi-angle multispectral water quality detection method. Background Technology

[0002] Water quality detection technology based on spectral imaging has been widely used in the field of water environment monitoring due to its advantages such as non-contact, large-scale, and rapid detection. In existing technologies, multispectral or hyperspectral imaging equipment mounted on UAVs or shipborne platforms is typically used to image the water surface, and key water quality parameters such as ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) are retrieved by analyzing the spectral characteristics of water reflectance in different bands.

[0003] However, the aforementioned existing technical solutions still have significant shortcomings in practical applications. First, when using mobile platforms such as drones or rotating devices for multi-angle observation, there are significant differences in reflectance of spectral data acquired from the same water body area at different observation angles. Existing technologies generally lack effective correction mechanisms for these differences caused by angle changes, easily misinterpreting angle effects as water quality changes, severely affecting inversion accuracy. Second, the displacement of the mobile platform during the detection process leads to inconsistencies in spatial reference and observation geometry between multi-temporal data, which is not conducive to long-term, continuous comparative monitoring. In addition, relying solely on remote sensing inversion models lacks ground truth calibration, resulting in poor model stability; while traditional contact water quality detection, although highly accurate, is limited to single-point sampling and cannot obtain spatial distribution information of water bodies. Summary of the Invention

[0004] To address these issues, this invention provides a shore-based fixed multi-angle multispectral water quality detection method to solve the problems in existing technologies, such as inconsistent spectral data due to changes in observation angle, poor data comparability due to moving platforms, and difficulty in simultaneously obtaining high-precision and spatial distribution information.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A shore-based fixed multi-angle multispectral water quality detection method includes the following steps:

[0007] A multispectral imaging device and a contact water quality testing device are fixedly installed on the shore of the target water body. During the water quality testing process, the positions of the multispectral imaging device and the contact water quality testing device remain unchanged.

[0008] By changing the observation angle of the multispectral imaging device, multispectral imaging is performed on water areas located at different spatial positions to obtain corresponding multispectral image data, and imaging geometric parameters corresponding to the multispectral image data are obtained.

[0009] Based on the imaging geometric parameters, a two-way reflectance distribution function model of the target water body is constructed, and the two-way reflectance distribution function model is used to correct the multispectral image data acquired at different observation angles to obtain corrected multispectral data.

[0010] The water quality parameter data measured by the contact water quality testing equipment is obtained, and the corrected multispectral data is calibrated or corrected based on the water quality parameter data to construct a water quality parameter inversion model and output the water quality testing results of the target water body.

[0011] Preferably, the water body regions in different spatial locations include at least two of the following: near-shore water body regions, central water body regions of the river channel, and water body regions far from the shore.

[0012] Preferably, the imaging geometry parameters include at least one of the solar incidence angle, imaging observation angle, and imaging azimuth angle.

[0013] Preferably, the bidirectional reflection distribution function model is used to describe the reflection characteristics of water bodies under different incident and observation directions.

[0014] Preferably, the water quality parameter data includes at least one of ammonia nitrogen, chemical oxygen demand, biochemical oxygen demand, turbidity, and conductivity.

[0015] Preferably, the model calibration or correction based on water quality parameter data includes using the water quality parameter data to correct or constrain the model parameters of the water quality parameter inversion model.

[0016] To achieve the above objectives, the present invention also provides the following technical solution:

[0017] A shore-based fixed multi-angle multispectral water quality monitoring system includes:

[0018] The multispectral imaging device is fixedly installed on the shore of the target water body and is equipped with a rotating mechanism to change the observation angle while keeping the device position unchanged, so as to obtain multispectral image data of the water body area at different spatial locations.

[0019] Contact-type water quality testing equipment is fixedly installed in the target water body to obtain water quality parameter data;

[0020] The data processing unit is communicatively connected to the multispectral imaging device and the contact water quality testing device. It is used to acquire imaging geometric parameters, construct a bidirectional reflectance distribution function model, correct the multispectral image data, construct a water quality parameter inversion model based on the water quality parameter data, and output the water quality testing results.

[0021] Preferably, the rotation mechanism is used to enable the multispectral imaging device to rotate in the horizontal and / or pitch directions.

[0022] Preferably, the data processing unit includes:

[0023] The system includes a multispectral data acquisition module, an imaging geometric parameter acquisition module, a bidirectional reflectance distribution function correction module, a water quality data acquisition module, and a water quality inversion and model correction module.

[0024] Preferably, the water quality test results are used for long-term continuous monitoring of water quality or analysis of water quality change trends.

[0025] The present invention has the following advantages:

[0026] By using shore-based fixed multispectral imaging equipment, the equipment position is kept unchanged during the detection process, ensuring the spatial consistency of water quality detection data across multiple time phases and angles, which is beneficial for long-term continuous monitoring and result comparison analysis.

[0027] By introducing a two-way reflectance distribution function model under multi-angle observation conditions, the reflectance differences caused by changes in observation angle are corrected, thereby improving the consistency of multispectral data and the accuracy of water quality parameter inversion results.

[0028] By introducing water quality parameter data obtained from contact water quality testing equipment into the water quality inversion process, the inversion model is calibrated or corrected. This ensures the accuracy of the test while taking into account the spatial distribution information of water quality, thus improving the stability and reliability of the water quality test results.

[0029] Without increasing the complexity of the detection platform, it achieves effective coverage of near-shore, river center and distant water areas, which has high practical value and promotion significance. Attached Figure Description

[0030] To more intuitively illustrate the prior art and this application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0031] Figure 1 This is a system schematic diagram of a shore-based fixed multi-angle multispectral water quality detection method provided in an embodiment of this application. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these embodiments are merely for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Technical engineers in the field can make some non-essential improvements and adjustments to the present invention based on the above-described content. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figure 1 A shore-based fixed multi-angle multispectral water quality detection method includes the following steps:

[0034] A multispectral imaging device and a contact water quality testing device are fixedly installed on the shore of the target water body. During the water quality testing process, the positions of the multispectral imaging device and the contact water quality testing device remain unchanged.

[0035] By changing the observation angle of the multispectral imaging device, multispectral imaging is performed on water areas located at different spatial positions to obtain corresponding multispectral image data, and imaging geometric parameters corresponding to the multispectral image data are obtained.

[0036] Based on the imaging geometric parameters, a two-way reflectance distribution function model of the target water body is constructed, and the two-way reflectance distribution function model is used to correct the multispectral image data acquired at different observation angles to obtain corrected multispectral data.

[0037] The water quality parameter data measured by the contact water quality testing equipment is obtained, and the corrected multispectral data is calibrated or corrected based on the water quality parameter data to construct a water quality parameter inversion model and output the water quality testing results of the target water body.

[0038] Its specific implementation includes the following steps:

[0039] (1) A multispectral imaging device and a contact water quality testing device are installed on the shore of the target water body, wherein the multispectral imaging device and the contact water quality testing device remain in fixed positions during the water quality testing process and do not undergo spatial displacement. The multispectral imaging device is equipped with a rotating mechanism for changing the observation direction or observation angle of the imaging device.

[0040] (2) By rotating the observation angle of the multispectral imaging device, multispectral imaging is performed on water areas located in different spatial positions. The water areas include, but are not limited to, near-shore areas, river center areas and water areas far from the shore, and corresponding multispectral image data is obtained.

[0041] (3) While performing multispectral imaging, the imaging geometric parameters corresponding to each imaging are obtained, including the solar incidence angle, imaging observation angle and imaging azimuth angle.

[0042] (4) Construct a bidirectional reflectance distribution function model of the target water body based on the imaging geometric parameters, and use the bidirectional reflectance distribution function model to perform reflectance correction on the multispectral image data obtained under different observation angles, so as to eliminate the reflection difference caused by the change of observation angle and obtain corrected multispectral data with consistent angle.

[0043] (5) Obtain water quality parameter data at the corresponding time by means of a contact water quality testing device installed in the target water body, wherein the water quality parameters include at least one of ammonia nitrogen, chemical oxygen demand, biochemical oxygen demand, turbidity and conductivity.

[0044] (6) Based on the water quality parameter data obtained by the contact water quality testing equipment, the multispectral data after correction by the bidirectional reflectance distribution function is modeled or corrected to construct a water quality parameter inversion model, and the water quality test results of the target water body are output according to the water quality parameter inversion model.

[0045] Through the above implementation methods, multi-angle water quality detection of water bodies in different spatial locations can be achieved without relying on a mobile platform.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A shore-based fixed multi-angle multispectral water quality detection method, characterized in that, Includes the following steps: A multispectral imaging device and a contact water quality testing device are fixedly installed on the shore of the target water body. During the water quality testing process, the positions of the multispectral imaging device and the contact water quality testing device remain unchanged. By changing the observation angle of the multispectral imaging device, multispectral imaging is performed on water areas located at different spatial positions to obtain corresponding multispectral image data, and imaging geometric parameters corresponding to the multispectral image data are obtained. Based on the imaging geometric parameters, a two-way reflectance distribution function model of the target water body is constructed, and the two-way reflectance distribution function model is used to correct the multispectral image data acquired at different observation angles to obtain corrected multispectral data. The water quality parameter data measured by the contact water quality testing equipment is obtained, and the corrected multispectral data is calibrated or corrected based on the water quality parameter data to construct a water quality parameter inversion model and output the water quality testing results of the target water body.

2. The shore-based fixed multi-angle multispectral water quality detection method according to claim 1, characterized in that, The water body regions in different spatial locations include at least two of the following: near-shore water body regions, central water body regions of the river channel, and water body regions far from the shore.

3. The shore-based fixed multi-angle multispectral water quality detection method according to claim 1, characterized in that, The imaging geometry parameters include at least one of the solar incidence angle, imaging observation angle, and imaging azimuth angle.

4. The shore-based fixed multi-angle multispectral water quality detection method according to claim 1, characterized in that, The bidirectional reflection distribution function model is used to describe the reflection characteristics of water bodies under different incident and observation directions.

5. The shore-based fixed multi-angle multispectral water quality detection method according to claim 1, characterized in that, The water quality parameters include at least one of ammonia nitrogen, chemical oxygen demand (COD), biochemical oxygen demand (BOD), turbidity, and conductivity.

6. The shore-based fixed multi-angle multispectral water quality detection method according to claim 1, characterized in that, The process of calibrating or correcting the model based on water quality parameter data includes using the water quality parameter data to correct or constrain the model parameters of the water quality parameter inversion model.

7. A shore-based fixed multi-angle multispectral water quality detection system, characterized in that, include: The multispectral imaging device is fixedly installed on the shore of the target water body and is equipped with a rotating mechanism to change the observation angle while keeping the device position unchanged, so as to obtain multispectral image data of the water body area at different spatial locations. Contact-type water quality testing equipment is fixedly installed in the target water body to obtain water quality parameter data; The data processing unit is communicatively connected to the multispectral imaging device and the contact water quality testing device. It is used to acquire imaging geometric parameters, construct a bidirectional reflectance distribution function model, correct the multispectral image data, construct a water quality parameter inversion model based on the water quality parameter data, and output the water quality testing results.

8. The shore-based fixed multi-angle multispectral water quality detection system according to claim 7, characterized in that, The rotation mechanism is used to enable the multispectral imaging device to rotate in the horizontal and / or pitch directions.

9. A shore-based fixed multi-angle multispectral water quality detection system according to claim 7, characterized in that, The data processing unit includes: The system includes a multispectral data acquisition module, an imaging geometric parameter acquisition module, a bidirectional reflectance distribution function correction module, a water quality data acquisition module, and a water quality inversion and model correction module.

10. A shore-based fixed multi-angle multispectral water quality detection system according to claim 7, characterized in that, The water quality test results are used for long-term continuous monitoring of water quality or analysis of water quality change trends.

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