In-situ measuring device and method for spectral measurement of shallow lake

Abstract

This invention belongs to the field of water environment monitoring technology, specifically relating to an in-situ spectral measurement device and method for shallow lakes. The measurement device includes a housing and a water-passing grid module. A vertical rangefinder, an adjustable mounting bracket, a fixed mounting bracket, and a communication module are mounted on the top of the housing. The adjustable and fixed mounting brackets are used to mount the light source and the spectrometer, respectively. A water inlet is vertically opened in the middle of the side wall of the housing. The water-passing grid module includes a light-blocking baffle and a traction ring. The light-blocking baffle is slidably mounted on the side wall of the housing and is correspondingly positioned to the water inlet. The traction ring is installed on top of the light-blocking baffle and is used to move the light-blocking baffle up and down along the water inlet as it floats with the water level. A signal trigger is located on the side wall of the housing near the top of the water inlet. This invention achieves fully automatic spectral measurement and combines the in-situ characteristics of field acquisition with the illumination stability of darkroom acquisition.

Description

Technical Field

[0001] This invention belongs to the field of water environment monitoring technology, specifically relating to an in-situ spectral measurement device and method for shallow lakes. Background Technology

[0002] With the increasing prominence of global water environment problems, the demand for monitoring aquatic ecosystems has significantly increased. Shallow lakes, as important ecological resources, not only provide essential water sources for humans and other organisms but also play a crucial role in regulating climate and maintaining biodiversity. In water environment monitoring, spectral measurement has become a key analytical tool due to its ability to rapidly and non-destructively detect the physical, chemical, and biological characteristics of water bodies. However, existing water spectral acquisition methods have certain limitations in practice. For example, the invention patent application CN201810710223.5 provides a method for quantitative inversion of hyperspectral water quality parameters based on spectral morphology characteristics. This method involves on-site spectral measurement at water sample collection points to obtain spectral data for analysis. This method relies on sunlight as a light source for in-situ spectral acquisition of water bodies. However, sunlight is easily affected by weather, angle of illumination, and climatic conditions, leading to unstable light intensity. Therefore, on-site acquisition methods are difficult to achieve stable all-weather monitoring on cloudy days, at night, or when there are large waves. Furthermore, waves can disturb the water surface, affecting the quality of the measurement signal and thus reducing the accuracy and consistency of the data. The invention patent application CN202110915573.7 discloses a water quality measurement device and method using a multispectral sensor. This method employs a darkroom spectral measurement approach, collecting water samples in a laboratory and simulating illumination conditions with an artificial light source to achieve multi-wavelength spectral measurement. Although this method avoids the influence of climate in the natural environment and the experimental light source is relatively stable, the physical and chemical properties of the water sample may change during collection, transfer, and experimental operations, making it difficult to accurately reflect the in-situ state of the sampling point. Therefore, existing methods for in-situ dynamic monitoring of water bodies have the aforementioned limitations. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in the existing technology by providing a fully automated in-situ spectral measurement device and method for shallow lakes that combines the in-situ characteristics of field acquisition with the illumination stability of darkroom acquisition.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] In a first aspect, the present invention provides an in-situ spectral measurement device for shallow lakes. The device includes a housing and a water-passing grid module. A vertical rangefinder, an adjustable mounting bracket, a fixed mounting bracket, and a communication module are disposed on the top of the housing. The adjustable mounting bracket is used to mount a light source, and the fixed mounting bracket is used to mount a spectrometer. A water inlet is vertically opened in the middle of the side wall of the housing. The water-passing grid module includes a light-blocking baffle and a traction ring. The light-blocking baffle is slidably disposed on the side wall of the housing and is correspondingly disposed with the water inlet. The traction ring is installed on the top of the light-blocking baffle and is used to drive the light-blocking baffle to float up and down along the water inlet when it floats up and down with the water level. A signal trigger is disposed on the side wall of the housing near the top of the water inlet. The signal input terminal of the communication module is connected to the signal trigger and the signal output terminal of the vertical rangefinder. The signal output terminal of the communication module is connected to the signal input terminal of the vertical rangefinder and the adjustable mounting bracket.

[0006] The signal trigger is used to be activated when the light-blocking baffle floats upward along the water inlet until it contacts the signal trigger.

[0007] The communication module is used to receive the trigger signal from the signal trigger and then control the vertical rangefinder to detect the distance between the top of the shell and the water surface. Based on the distance measurement result of the vertical rangefinder, it controls the adjustable mounting bracket to adjust the illumination angle of the light source. Finally, it starts the spectrometer and the light source to perform spectral measurement.

[0008] The adjustable mounting bracket includes a first support column, a rotating shaft, an adjustment mechanism, and a first mounting plate. The first support column is mounted on the top of the housing. The rotating shaft is rotatably mounted on the first support column and is horizontally positioned. The first mounting plate is mounted on the bottom of the rotating shaft and is provided with a first fixing clamp for mounting a light source. The adjustment mechanism is mounted on the top of the rotating shaft and is used to rotate the rotating shaft to adjust the illumination angle of the light source.

[0009] The fixed mounting bracket includes a second support column and a second mounting plate. The second support column is installed on the top of the housing, and the second mounting plate is installed on the second support column. A second fixing clamp is provided on the second mounting plate, and the second fixing clamp is used to install the spectrometer.

[0010] An adsorption device is also provided on the side wall of the housing near the top of the water inlet. The adsorption device includes an electromagnetic adsorption block and a control circuit assembly. The signal input terminal of the control circuit assembly is connected to the signal output terminal of the communication module. After receiving a trigger signal from a signal trigger, the communication module sends an energizing signal to the control circuit assembly. The control circuit assembly is used to control the electromagnetic adsorption block to be energized after receiving the energizing signal. The electromagnetic adsorption block is used to generate a magnetic field when energized so as to attract the metal insert set inside the traction ring.

[0011] The measuring device also includes a power supply device, which supplies power to the signal trigger, vertical rangefinder, adjustable mounting bracket spectrometer, light source, adsorption device, and communication module.

[0012] The measuring device also includes a satellite positioning signal receiver. The signal output terminal of the satellite positioning signal receiver is connected to the signal input terminal of the communication module. The satellite positioning signal receiver is used to receive satellite positioning signals and send them to the communication module. The communication module is also used to send the spectral measurement data received from the spectrometer and the satellite positioning signals received from the satellite positioning signal receiver to the user terminal.

[0013] The adjustable mounting bracket and the vertical rangefinder are symmetrically arranged on both sides of the fixed mounting bracket.

[0014] The shell is a hollow cylinder with an open bottom, and the surface of the shell is coated with an anti-corrosion coating.

[0015] Secondly, the present invention provides a measurement method based on the aforementioned shallow lake spectral in-situ measurement device, the measurement method comprising:

[0016] S1. Place the entire measuring device into the water of the target area of ​​the lake. As water enters the shell, the water level inside the shell rises. The light-blocking baffle floats upward along the water inlet until it contacts the signal trigger. The signal trigger is triggered and sends the trigger signal to the communication module.

[0017] S2. After receiving a trigger signal from a signal trigger, the communication module controls the vertical rangefinder to detect the distance between the top of the housing and the water surface, and then controls the adjustable mounting bracket to adjust the illumination angle of the light source based on the distance measurement result of the vertical rangefinder.

[0018] S3. The communication module (7) controls the spectrometer and light source to start spectral measurement and obtain spectral measurement data.

[0019] The formula for adjusting the irradiation angle is:

[0020] 𝜃=arctan(d / ℎ);

[0021] In the above formula, 𝜃 is the illumination angle; ℎ represents the vertical distance between the top of the shell and the water surface measured by the vertical rangefinder; d is the horizontal distance between the adjustable mounting bracket and the fixed mounting bracket.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The in-situ spectral measurement device for shallow lakes according to the present invention includes a housing and a water-passing grid module. A vertical rangefinder, an adjustable mounting bracket, a fixed mounting bracket, and a communication module are mounted on the top of the housing. The adjustable and fixed mounting brackets are used to mount the light source and the spectrometer, respectively. A water inlet is vertically opened in the middle of the side wall of the housing. The water-passing grid module includes a light-blocking baffle and a traction ring. The light-blocking baffle is slidably mounted on the side wall of the housing and is correspondingly positioned to the water inlet. The traction ring is installed on the top of the light-blocking baffle and is used to drive the light-blocking baffle to move up and down along the water inlet as it floats with the water level. A signal trigger is located on the side wall of the housing near the top of the water inlet. The signal input terminal of the communication module is connected to the signal trigger and the signal output terminal of the vertical rangefinder. The signal output terminal of the communication module is connected to the signal input terminal of the vertical rangefinder and the adjustable mounting bracket. During measurement, the entire measurement device is placed in the lake... In the target area, as water enters the shell, the water level rises. A light-blocking baffle floats upwards along the water inlet until it contacts a signal trigger, activating the trigger and sending a signal to the communication module. Upon receiving the trigger signal, the communication module first controls a vertical rangefinder to detect the distance between the top of the shell and the water surface. Based on the rangefinder's measurement, it controls an adjustable mounting bracket to adjust the illumination angle of the light source. Finally, it activates the spectrometer and light source to perform spectral measurements, obtaining spectral data for subsequent analysis and detection. This design, by incorporating a water-passing grid module on the shell, allows water to flow freely in and out at low water levels. When the water level reaches a certain height, a closed darkroom environment is formed, ensuring that spectral measurements are not affected by external weather factors. This ensures stable illumination during the measurement process while enabling real-time, dynamic acquisition of the water's spectral characteristics. Therefore, this invention achieves fully automated spectral measurement, combining the in-situ characteristics of field acquisition with the illumination stability of darkroom acquisition.

[0024] 2. The in-situ spectral measurement device for shallow lakes described in this invention can adjust the illumination angle of the light source based on the distance measurement results of a vertical rangefinder, ensuring uniform illumination of the water body and guaranteeing optimal observation results for the spectrometer, thereby ensuring high measurement accuracy. Therefore, this invention can guarantee high measurement accuracy. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the measuring device described in this invention.

[0026] Figure 2 for Figure 1 A schematic diagram of the adjustable mounting bracket.

[0027] Figure 3 for Figure 1 A schematic diagram of the structure of the fixed mounting bracket.

[0028] Figure 4 for Figure 1 A schematic diagram of the adsorption device.

[0029] In the diagram above, the components are: housing 1, water inlet 11, signal trigger 12, vertical rangefinder 2, adsorption device 3, electromagnetic adsorption block 31, control circuit assembly 32, protective shell 33, power supply device 4, adjustable mounting bracket 5, first support column 51, rotating shaft 52, adjustment mechanism 53, first mounting plate 54, first fixing clamp 55, fixed mounting bracket 6, second support column 61, second mounting plate 62, second fixing clamp 63, communication module 7, water gate module 8, light shield 81, traction ring 82, and satellite positioning signal receiver 9. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0031] See Figure 1 This invention provides a preferred embodiment of a shallow lake spectral in-situ measurement device, comprising a housing 1 and a water-passing grid module 8. The top of the housing 1 is equipped with a vertical rangefinder 2, an adjustable mounting bracket 5, a fixed mounting bracket 6, and a communication module 7. The adjustable mounting bracket 5 is used to mount a light source, and the fixed mounting bracket 6 is used to mount the spectrometer. A water inlet 11 is vertically opened in the middle of the side wall of the housing 1. The water-passing grid module 8 includes a light-blocking baffle 81 and a traction ring 82. The light-blocking baffle 81 is slidably disposed on the side wall of the housing 1, and is correspondingly disposed with the water inlet 11. The traction ring 82 is installed on the top of the light-blocking baffle 81 and is used to drive the light-blocking baffle 81 to float up and down along the water inlet 11 when it floats up and down with the water level. A signal trigger 12 is disposed on the side wall of the housing 1 near the top of the water inlet 11. The signal input terminal of the communication module 7 is connected to the signal trigger 12 and the signal output terminal of the vertical rangefinder 2, and the signal output terminal of the communication module 7 is connected to the signal input terminal of the vertical rangefinder 2 and the adjustable mounting bracket 5.

[0032] The working principle of the above-mentioned measuring device is as follows: The entire measuring device is placed in the water of the target area of ​​the lake. As water enters the interior of the housing 1, the water level inside the housing 1 rises. The light-blocking baffle 81 floats upward along the water inlet 11 until it contacts the signal trigger 12. The signal trigger 12 is triggered and sends the trigger signal to the communication module 7. After receiving the trigger signal from the signal trigger 12, the communication module 7 controls the vertical rangefinder 2 to detect the distance between the top of the housing 1 and the water surface. Based on the distance measurement result of the vertical rangefinder 2, the adjustable mounting bracket 5 is controlled to adjust the illumination angle of the light source. After the angle is adjusted, the spectrometer and the light source are started to perform spectral measurement. Finally, the spectral measurement data is transmitted to the user terminal.

[0033] Compared with existing lake spectral measurement devices, the above-mentioned device can measure in-situ spectra in all weather conditions, overcoming the dependence of traditional devices on natural light. Furthermore, since it measures spectral data directly in-situ in the lake, it is not necessary to bring water samples back to the laboratory, effectively avoiding changes in water samples during transportation and storage, and ensuring the authenticity and reliability of the measurement data. In addition, the water-passing grid module 8 uses the natural rise and fall of water level to create a dark chamber. That is, the buoyancy of water automatically pushes the light-blocking baffle 81 upward to a closed state to form a dark chamber. When the water level drops, the light-blocking baffle 81 naturally falls back, without the need for additional motor drive, which greatly simplifies the complexity of the control system, reduces the energy consumption and maintenance requirements of the equipment, and also improves the reliability and environmental adaptability of the system.

[0034] Specifically, the light-blocking baffle 81 is made of a corrosion-resistant, high-strength, and less dense than water opaque material. The light-blocking baffle 81 is designed to slide up and down along the side wall of the housing 1 using a slide rail and guide block, thereby controlling the inflow and outflow of water. The traction ring 82 is fixed to the top of the light-blocking baffle 81 and is made of a high-strength and highly buoyant opaque material. It can float up and down with changes in water level, thereby driving the light-blocking baffle 81 to slide up and down. This design takes into account the characteristics of water level fluctuations. When the water level rises, the traction ring 82 guides the light-blocking baffle 81 to slide upward until it slides to the top of the water inlet 11, closing the water inlet 11 and forming a sealed dark chamber inside the housing 1, effectively preventing external light from entering, thereby ensuring the accuracy of spectral measurement. The signal trigger 12 is located near the top of the water inlet 11. Its main function is to monitor whether the water inlet 11 is closed. When the water level rises, the traction ring 82 guides the light-blocking baffle 81 to slide upward until the water inlet 11 is closed. The signal trigger 12 is then triggered and sends a signal to the communication module 7. After receiving the trigger signal, the communication module 7 starts the spectral measurement task.

[0035] The aforementioned measuring device can be equipped with an appropriate spectrometer to meet the spectral monitoring needs of lakes with varying turbidity levels. For highly eutrophic lakes, due to the high content of suspended solids, organic matter, and algae, a spectrometer adapted to high turbidity can be used, effectively improving measurement accuracy and reducing interference. For mesotrophic and hypotrophic lakes, a spectrometer adapted to lower turbidity can be used, enabling highly sensitive measurements of these water bodies. This flexible spectrometer configuration ensures the applicability and versatility of the measuring device in different aquatic environments, thus providing technical support for the precise monitoring of shallow lake ecosystems.

[0036] In another embodiment of the invention, see Figure 2The adjustable mounting bracket 5 includes a first support column 51, a rotating shaft 52, an adjustment mechanism 53, and a first mounting plate 54. The first support column 51 is mounted on the top of the housing 1. The rotating shaft 52 is rotatably mounted on the first support column 51 and is horizontally positioned. The first mounting plate 54 is mounted on the bottom of the rotating shaft 52 and has a first fixing clamp 55 for mounting a light source. The adjustment mechanism 53 is mounted on the top of the rotating shaft 52 and is used to rotate the rotating shaft 52 to adjust the illumination angle of the light source. By adjusting the illumination angle of the light source to a suitable angle, the light source is ensured to uniformly illuminate the water body, ensuring that the spectrometer can achieve the best observation effect, thereby ensuring high measurement accuracy. As one implementation, the adjustment mechanism 53 can be a rotary cylinder or a linear motor. The signal input terminal of the adjustment mechanism 53 is connected to the signal output terminal of the communication module 7. Since field spectral measurements are typically taken between 9:00 and 11:00 AM and between 1:00 and 3:00 PM, when the solar altitude angle is between 45° and 70°, to simulate sunlight, the angle of illumination from the light source is controlled within the range of 20° to 45°. This angle control can be achieved by using limiters on both sides of the rotating shaft 52.

[0037] In another embodiment of the invention, see Figure 3 The fixed mounting bracket 6 includes a second support column 61 and a second mounting plate 62. The second support column 61 is mounted on the top of the housing 1, and the second mounting plate 62 is mounted on the second support column 61. A second fixing clamp 63 is provided on the second mounting plate 62. The second fixing clamp 63 is used to mount the spectrometer, and the spectrometer always illuminates the water surface perpendicularly.

[0038] In another embodiment of the invention, see Figure 4An adsorption device 3 is also provided on the side wall of the housing 1 near the top of the water inlet 11. The adsorption device 3 includes a protective shell 33 and an electromagnetic adsorption block 31 and a control circuit assembly 32 encapsulated inside the protective shell 33. The protective shell 33 is made of waterproof and corrosion-resistant material. The signal input terminal of the control circuit assembly 32 is connected to the signal output terminal of the communication module 7. The communication module 7 is also used to send an energizing signal to the control circuit assembly 32 after receiving a trigger signal from the signal trigger 12. The control circuit assembly 32 is used to control the electromagnetic adsorption block 31 to be energized after receiving the energizing signal. The electromagnetic adsorption block 31 is used to generate a magnetic field when energized so as to be attracted to the metal insert set inside the traction ring 82, ensuring that the light-blocking baffle 81 can stably close the water inlet 11 and prevent the light-blocking baffle 81 from sliding due to wind waves or water flow disturbance. After the spectral measurement is completed, the communication module 7 sends a power-off signal to the control circuit component 32. Upon receiving the power-off signal, the control circuit component 32 controls the electromagnetic adsorption block 31 to de-energize. This safety release mechanism ensures that the light-blocking baffle 81 can resume normal movement after the spectral measurement is completed, so that the next measurement can be carried out. Moreover, no mechanical reset device is required. The water inlet 11 can be restored to the open state by the gravity of the light-blocking baffle 81 and the action of water flow.

[0039] Specifically, the communication module 7 is also used to receive measurement instructions from the user terminal, such as setting it to timed measurement (once every 4 hours), thereby achieving precise control and flexible measurement, and improving the automation level of the measurement device.

[0040] In another embodiment of the invention, the measuring device further includes a power supply device 4, which supplies power to the signal trigger 12, vertical rangefinder 2, adjustable mounting bracket 5, fixed mounting bracket 6, adsorption device 3, communication module 7, spectrometer, and light source. The power supply device 4 provides stable power support for the entire measuring device, ensuring the normal operation of the light source and spectrometer. The power supply device 4 can be equipped with a solar panel, enabling it to be recharged during the day using solar energy, further extending the operating time of the measuring device and enhancing its autonomy and stability in outdoor monitoring.

[0041] In another embodiment of the present invention, the measuring device further includes a satellite positioning signal receiver 9, the signal output terminal of the satellite positioning signal receiver 9 being connected to the signal input terminal of the communication module 7, the satellite positioning signal receiver 9 being used to receive satellite positioning signals and send them to the communication module 7, and the communication module 7 being used to send the spectral measurement data received from the spectrometer and the satellite positioning signals received from the satellite positioning signal receiver 9 to the user terminal.

[0042] Specifically, the satellite positioning signal receiver 9 is encapsulated with corrosion-resistant and interference-resistant materials, making it suitable for long-term use in humid environments to ensure stable signal reception. The communication module 7 includes a high-sensitivity signal processor and a wireless transmission module, enabling stable signal transmission and ensuring data is transmitted to the user terminal without interference, even over long distances. The user terminal supports real-time data storage and viewing, and users can access historical data at any time for analysis and management, meeting the needs of long-term monitoring and research of lake water spectra.

[0043] In another embodiment of the present invention, the adjustable mounting bracket 5 and the vertical rangefinder 2 are symmetrically arranged on both sides of the fixed mounting bracket 6.

[0044] In another embodiment of the invention, the housing 1 is a hollow cylinder with an open bottom. The surface of the housing 1 is coated with an anti-corrosion coating to adapt to the long-term immersion environment in lakes, thereby ensuring the durability and stability of the structure. The bottom of the housing 1 can be firmly fixed to the lake bottom by anchoring or using an adjustable base, thereby adapting to different lake depths and flow conditions and keeping the device stable during water fluctuations. The top of the housing 1 can be equipped with a load-bearing device, which not only supports other functional components but also has a shock-absorbing function to buffer vibrations caused by water flow or waves, ensuring the accuracy and stability of the device during measurement.

[0045] This invention also provides an in-situ method for spectral measurement in shallow lakes, which comprises the following steps:

[0046] S1. Place the entire measuring device into the water body of the target area of ​​the lake. As water enters the interior of the housing 1, the water level inside the housing 1 rises. The light-blocking baffle 81 floats upward along the water inlet 11 until it contacts the signal trigger 12. The signal trigger 12 is triggered and sends the trigger signal to the communication module 7.

[0047] S2. After receiving the trigger signal from the signal trigger 12, the communication module 7 controls the vertical rangefinder 2 to detect the distance between the top of the housing 1 and the water surface. Based on the distance measurement result of the vertical rangefinder 2, it controls the adjustable mounting bracket 5 to adjust the illumination angle of the light source. The illumination angle is calculated according to the following formula:

[0048] 𝜃=arctan(d / ℎ);

[0049] In the above formula, 𝜃 is the illumination angle; ℎ represents the vertical distance between the top of the shell 1 and the water surface measured by the vertical rangefinder 2; d is the horizontal distance between the adjustable mounting bracket 5 and the fixed mounting bracket 6;

[0050] S3. The communication module 7 controls the spectrometer and light source to start spectral measurement and obtain spectral measurement data for water quality analysis.

[0051] Those skilled in the art will readily understand that the above description is merely 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 scope of protection of the present invention.

Claims

1. A shallow lake spectral in-situ measurement device, characterized in that: The measuring device includes a housing (1) and a water-passing grid module (8). The top of the housing (1) is equipped with a vertical rangefinder (2), an adjustable mounting bracket (5), a fixed mounting bracket (6), and a communication module (7). The adjustable mounting bracket (5) is used to mount a light source, and the fixed mounting bracket (6) is used to mount a spectrometer. A water inlet (11) is vertically opened in the middle of the side wall of the housing (1). The water-passing grid module (8) includes a light-blocking baffle (81) and a traction ring (82). The light-blocking baffle (81) is slidably mounted on the side wall of the housing (1), and the light-blocking baffle (81)... 81) Corresponding to the water inlet (11), the traction ring (82) is installed on the top of the light-blocking baffle (81) and is used to drive the light-blocking baffle (81) to float up and down along the water inlet (11) when it floats up and down with the water level; a signal trigger (12) is provided on the side wall of the housing (1) near the top of the water inlet (11); the signal input end of the communication module (7) is connected to the signal trigger (12) and the signal output end of the vertical distance measuring instrument (2); the signal output end of the communication module (7) is connected to the signal input end of the vertical distance measuring instrument (2) and the adjustable mounting bracket (5); The signal trigger (12) is used to be triggered when the light-blocking baffle (81) floats upward along the water inlet (11) and comes into contact with the signal trigger (12); The communication module (7) is used to receive the trigger signal from the signal trigger (12) and then control the vertical rangefinder (2) to detect the distance between the top of the shell (1) and the water surface. Based on the distance measurement result of the vertical rangefinder (2), the adjustable mounting bracket (5) is controlled to adjust the illumination angle of the light source. Finally, the spectrometer and the light source are started to perform spectral measurement. The adjustable mounting bracket (5) includes a first support column (51), a rotating shaft (52), an adjustment mechanism (53), and a first mounting plate (54). The first support column (51) is mounted on the top of the housing (1). The rotating shaft (52) is rotatably mounted on the first support column (51) and is horizontally mounted. The first mounting plate (54) is mounted on the bottom of the rotating shaft (52) and is provided with a first fixing clamp (55). The first fixing clamp (55) is used to mount the light source. The adjustment mechanism (53) is mounted on the top of the rotating shaft (52) and is used to rotate the rotating shaft (52) to adjust the illumination angle of the light source. The fixed mounting bracket (6) includes a second support column (61) and a second mounting plate (62). The second support column (61) is mounted on the top of the housing (1), and the second mounting plate (62) is mounted on the second support column (61). A second fixing clamp (63) is provided on the second mounting plate (62), and the second fixing clamp (63) is used to mount the spectrometer. An adsorption device (3) is also provided on the side wall of the housing (1) near the top of the water inlet (11). The adsorption device (3) includes an electromagnetic adsorption block (31) and a control circuit assembly (32). The signal input terminal of the control circuit assembly (32) is connected to the signal output terminal of the communication module (7). The communication module (7) is also used to send an energizing signal to the control circuit assembly (32) after receiving a trigger signal from the signal trigger (12). The control circuit assembly (32) is used to control the electromagnetic adsorption block (31) to be energized after receiving the energizing signal. The electromagnetic adsorption block (31) is used to generate a magnetic field when energized so as to be attracted to the metal insert set inside the traction ring (82).

2. The in-situ spectral measurement device for shallow lakes according to claim 1, characterized in that: The measuring device also includes a power supply device (4), which is used to supply power to the signal trigger (12), vertical rangefinder (2), adjustable mounting bracket (5), adsorption device (3), communication module (7), spectrometer, and light source.

3. The in-situ spectral measurement device for shallow lakes according to claim 1, characterized in that: The measuring device also includes a satellite positioning signal receiver (9), the signal output terminal of which is connected to the signal input terminal of the communication module (7). The satellite positioning signal receiver (9) is used to receive satellite positioning signals and send them to the communication module (7). The communication module (7) is also used to send the spectral measurement data received from the spectrometer and the satellite positioning signals received from the satellite positioning signal receiver (9) to the user terminal.

4. The in-situ spectral measurement device for shallow lakes according to claim 1, characterized in that: The adjustable mounting bracket (5) and the vertical rangefinder (2) are symmetrically arranged on both sides of the fixed mounting bracket (6).

5. The in-situ spectral measurement device for shallow lakes according to claim 1, characterized in that: The shell (1) is a hollow cylinder with an open bottom, and the surface of the shell (1) is coated with an anti-corrosion coating.

6. A measurement method based on the in-situ spectral measurement device for shallow lakes as described in claim 1, characterized in that: The measurement method includes: S1. Place the entire measuring device into the water body of the target area of ​​the lake. As water enters the interior of the housing (1), the water level inside the housing (1) rises. The light-blocking baffle (81) floats upward along the water inlet (11) until it contacts the signal trigger (12). The signal trigger (12) is triggered and sends the trigger signal to the communication module (7). S2. After receiving the trigger signal from the signal trigger (12), the communication module (7) controls the vertical rangefinder (2) to detect the distance between the top of the shell (1) and the water surface, and then controls the adjustable mounting bracket (5) to adjust the illumination angle of the light source based on the distance measurement result of the vertical rangefinder (2). S3. The communication module (7) controls the spectrometer and light source to start spectral measurement and obtain spectral measurement data.

7. The measurement method based on a shallow lake spectral in-situ measurement device according to claim 6, characterized in that: The formula for adjusting the irradiation angle is: 𝜃=arctan(d / ℎ); In the above formula, 𝜃 is the illumination angle; ℎ represents the vertical distance between the top of the shell (1) and the water surface measured by the vertical rangefinder (2); d is the horizontal distance between the adjustable mounting bracket (5) and the fixed mounting bracket (6).

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