Shallow sea substrate spectrum observation device and method

Abstract

The invention discloses a shallow sea substrate spectrum observation device and method. The device comprises a downlink radiation sensor, an uplink radiation sensor, a tripod landing frame fixing mechanism, an underwater camera and a movable calibration plate mechanism, and through the design of the movable calibration plate mechanism, the uplink radiation sensor, the downlink radiation sensor and the tripod landing frame fixing mechanism, the shallow sea sediment spectrum observation device with the position of the underwater calibration plate adjustable and the method are established. Based on an optical attenuation law in a water body, a movable calibration mechanism capable of changing the measurement height is designed, an information processing method is provided, and the measurement of the real spectrum of the seabed is realized. The method can play a great practical value in coral reef and sea grass bed ecosystem health monitoring and geological sediment research.

Description

Technical Field

[0001] The present invention belongs to the field of ocean observation, and relates to an observation device and method, and in particular to a shallow seabed seismic spectrum observation device and method. Background Art

[0002] The seabed of shallow seas hosts typical ecosystems such as coral reefs and seagrass beds, which are of great significance to fishery resources, coastal erosion protection, and climate regulation. In the existing shallow seabed observation methods, near-bottom observations by divers carrying survey instruments rely on labor costs and technical training costs. The direct optical observation results of the shallow seabed through satellite or aerial remote sensing methods are not stable due to the changing water quality and tidal conditions of shallow sea water bodies. How to obtain accurate optical quantitative information of the seabed through labor-saving on-site observation methods is an urgent need in marine observation and research work. From the retrieved public information, there is no similar shallow seabed seismic spectral observation device and method to realize the measurement function of optical quantitative information of the seabed.

[0003] Due to the changes in water quality conditions caused by seasons or precipitation and the changes in water depth caused by tide levels, the observation results of underwater information on the water surface are not fixed. Aiming at the need for the quantification of the above-mentioned submarine optical information, the present invention, based on the reflectivity calculation principle and the water optical attenuation principle, establishes a shallow seabed geological observation device and method with adjustable calibration information through a process-adjustable movable calibration plate mechanism, thereby removing the influence of the water column in the measurement of underwater optical quantitative information, and can be used for on-site observation of the health status of shallow sea ecosystems such as coral reefs and seagrass beds. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a shallow sea bottom spectrum observation device and method.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A shallow seabed geological spectrum observation device comprises a downlink radiation sensor, an uplink radiation sensor, a tripod landing frame fixing mechanism, an underwater camera and a movable calibration plate mechanism; the tripod landing frame fixing mechanism comprises an annular bracket and a first leg, a second leg and a third leg fixed on the annular bracket, the annular bracket is provided with a cross beam, and the downlink radiation sensor and the uplink radiation sensor are fixed on the cross beam; the underwater camera is fixed on the first leg of the tripod landing frame fixing mechanism; the movable calibration plate mechanism is fixed on the second leg of the tripod landing frame fixing mechanism.

[0007] Furthermore, the movable calibration plate mechanism includes a push rod and a reflectivity calibration whiteboard, one end of the push rod is fixed with the reflectivity calibration whiteboard, and the other end is fixed to the second leg of the tripod landing platform fixing mechanism, and the push rod can be extended and retracted to adjust the position of the reflectivity calibration whiteboard.

[0008] Furthermore, the downlink radiation sensor and the uplink radiation sensor are spectral measuring instruments with waterproof and pressure-resistant capabilities, and are used to measure the radiation intensity at a specific depth underwater.

[0009] Furthermore, a data collector is provided on the third leg of the tripod landing frame fixing mechanism, and the data collector is connected to the downlink radiation sensor, the uplink radiation sensor, the underwater camera and the movable calibration plate mechanism through a waterproof cable.

[0010] Furthermore, the observation device also includes a control module, which is connected to the data collector via a waterproof cable and is used to control the opening and closing of the downlink radiation sensor, the uplink radiation sensor, the underwater camera and the introduction of the movable calibration plate mechanism.

[0011] A shallow seabed seismic spectrum observation method is implemented using the above device, and the specific steps are as follows:

[0012] S1. Install the shallow seabed seismic spectrum observation device and lower the device through the ship-based platform until the tripod landing frame fixing mechanism lands on the bottom of the water;

[0013] S2. Observe the underwater target corresponding to the uplink radiation sensor through an underwater camera to determine the location and area of ​​the observation device being lowered;

[0014] S3. Using the downlink radiation sensor to collect the first environmental spectral data, and using the uplink radiation sensor to collect the spectral data of the bottom reflectance;

[0015] S4. Control the push rod of the movable calibration plate mechanism to push the reflectivity calibration white plate to the bottom of the uplink radiation sensor, collect the spectral data reflected by the reflectivity calibration white plate through the uplink radiation sensor, and simultaneously record the second environmental spectral data collected by the downlink radiation sensor;

[0016] S5. Process and analyze the spectral data of the bottom reflection, the spectral data of the reflectance calibration whiteboard reflection, and the environmental spectral data collected twice to obtain the reflectance data of the seabed bottom without the influence of the water column.

[0017] Furthermore, the underwater target corresponding to the upward radiation sensor is observed by an underwater camera to determine the lowering position and area of ​​the observation device. Specifically, the underwater target image is taken by the underwater camera to observe the bottom type corresponding to the upward radiation sensor to determine whether to measure in the area. Otherwise, it is necessary to adjust the lowering position or move to the next area for measurement through the ship-based platform.

[0018] Furthermore, the reflectivity data of the seabed without the influence of the water column is specifically calculated as follows:

[0019] Based on the spectral data of bottom reflection, the spectral data of reflectance calibration whiteboard reflection, the environmental spectral data collected twice, the height difference between the downlink radiation sensor and the uplink radiation sensor, and the distance between the uplink radiation sensor and the water bottom, the Beer-Lambert law is used to correct the optical attenuation and calculate the reflectivity of the seabed without the influence of the water column.

[0020] The beneficial effects of the present invention are:

[0021] The health status of ecosystems such as coral reefs and seagrass beds carried by shallow seabeds needs to be monitored regularly. In existing ocean observation methods, it is difficult to eliminate the influence of the water column between the sensor and the underwater target in both in-situ measurements performed by divers and aerial near-ground measurements. At the same time, due to the presence of waves and other phenomena at the water-air interface, the interference to the shallow underwater light field is also strong. The present invention is based on the law of optical attenuation in water bodies, and designs an active calibration mechanism that can change the measurement height, proposes an information processing method, and realizes the measurement of the true spectrum of the seabed. It is an innovation in marine field observation research. The present invention can be used for oceanographic in-situ surveys such as underwater ecosystem surveys and seabed sediment surveys, and has great practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of a shallow seabed geological spectrum observation device according to an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of parameters used in water column calibration by the device in an embodiment of the present invention.

[0024] Figure 3 It is an example diagram of the result of actual bottom measurement in the embodiment of the present invention.

[0025] Figure 4 It is an example diagram of comparison and verification of the results after the seabed sediment spectrum correction in the embodiment of the present invention.

[0026] In the figure, 1 is a downlink radiation sensor, 2 is an uplink radiation sensor, 3 is a tripod landing frame fixing mechanism, 4 is an underwater camera, 5 is a movable calibration plate mechanism, and 6 is a data collector. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is clearly and detailedly explained below in conjunction with the accompanying drawings and specific examples. Example 1

[0028] like Figure 1 As shown, a shallow seabed geological spectrum observation device comprises a downlink radiation sensor 1, an uplink radiation sensor 2, a tripod landing frame fixing mechanism 3, an underwater camera 4 and a movable calibration plate mechanism 5; the tripod landing frame fixing mechanism 3 is used to fix the relative positions of the movable calibration plate mechanism 5, the downlink radiation sensor 1 and the uplink radiation sensor 2, and comprises an annular bracket and a first leg, a second leg and a third leg fixed on the annular bracket, the annular bracket is provided with a crossbeam, and the downlink radiation sensor 1 and the uplink radiation sensor 2 are fixed on the crossbeam; the underwater camera 4 is a conventional underwater camera with waterproof and pressure resistance capabilities, fixed on the first leg of the tripod landing frame fixing mechanism 3, and used for observing the bottom of the water; the movable calibration plate mechanism 5 is fixed on the second leg of the tripod landing frame fixing mechanism 3; each instrument is connected to the tripod landing frame fixing mechanism 3 by a clamp fixed by bolts.

[0029] The movable calibration plate mechanism 5 is a watertight electromechanical device, including a push rod and a reflectivity calibration whiteboard, one end of the push rod is fixed with the reflectivity calibration whiteboard, and the other end is fixed to the second leg of the tripod landing frame fixing mechanism 3, and the push rod can be extended and retracted to adjust the position of the reflectivity calibration whiteboard. The push-out amplitude of the push rod can be controlled by the control module to make the reflectivity calibration whiteboard as close to the bottom of the water as possible and avoid underwater protrusions.

[0030] The downlink radiation sensor 1 and the uplink radiation sensor 2 are spectral measurement instruments with waterproof and pressure-resistant capabilities, and are used to measure the radiation intensity at a specific depth underwater.

[0031] A data collector 6 is provided on the third leg of the tripod landing frame fixing mechanism 3, and the data collector 6 is connected to the downlink radiation sensor 1, the uplink radiation sensor 2, the underwater camera 4 and the movable calibration plate mechanism 5 through a waterproof cable.

[0032] The observation device also includes a control module, which is connected to the data collector 6 via a waterproof cable and is used to control the opening and closing of the downlink radiation sensor 1, the uplink radiation sensor 2, the underwater camera 4 and the introduction of the movable calibration plate mechanism 5. Example 2

[0033] A method for observing shallow seabed seismic spectrum is implemented using the device in Example 1, and the specific steps are as follows:

[0034] S1. Install the shallow seabed seismic spectrum observation device and lower the device through the ship-based platform until the tripod landing frame fixing mechanism lands on the bottom of the water;

[0035] S2. Observe the underwater target corresponding to the uplink radiation sensor through an underwater camera to determine the location and area of ​​the observation device being lowered;

[0036] S3. Using the downlink radiation sensor to collect the first environmental spectral data, using the uplink radiation sensor to collect the spectral data of the bottom reflection;

[0037] S4. Control the push rod of the movable calibration plate mechanism to push the reflectivity calibration white plate to the bottom of the uplink radiation sensor, collect the spectral data reflected by the reflectivity calibration white plate through the uplink radiation sensor, and simultaneously record the second environmental spectral data collected by the downlink radiation sensor;

[0038] S5. Process and analyze the spectral data of the bottom reflection, the spectral data of the reflectance calibration whiteboard reflection, and the environmental spectral data collected twice to obtain the reflectance data of the seabed bottom without the influence of the water column.

[0039] Step S1 specifically includes: fixing each instrument to the tripod landing frame fixing mechanism 3 by bolting with a clamp of corresponding size, connecting each instrument to the data collector 6, and connecting the data collector 6 to the control module through a cable. After the corresponding preparations are completed, the device can be lowered into the water manually or by a winch on a ship-based platform until the tripod landing frame 3 lands on the bottom of the water. The installed device is as follows Figure 1 As shown in a in .

[0040] Step S2 specifically includes: after the tripod landing frame fixing mechanism 3 lands on the bottom of the water, the bottom type corresponding to the radiation sensor is observed through the underwater camera 4. This determines whether to measure in this area, otherwise it is necessary to appropriately adjust the landing position or move to the next area for measurement through the ship-based platform.

[0041] Step S3 is as follows: after the underwater camera determines the underwater type, the control module turns on the downlink radiation sensor and the uplink radiation sensor, and uses the uplink radiation sensor to collect the spectrum data of the bottom reflection, that is, the uplink radiation radiance L 1 , using the downlink radiation sensor to collect the first environmental spectrum data, that is, the downlink radiation irradiance E 1 The status of the device during the collection is as follows: Figure 1 As shown in a in .

[0042] Step S4 is specifically as follows: according to the need to remove the influence of the water column between the sensor and the seabed, the control module causes the push rod of the movable calibration plate mechanism to push the reflectivity calibration white plate to the bottom of the uplink radiation sensor to change the reflectivity of the measurement target, and collect the spectral data reflected by the reflectivity calibration white plate collected by the uplink radiation sensor under the corresponding situation, that is, the uplink radiation radiance L 0 ; Synchronously record the second environmental spectrum data collected by the downlink radiation sensor, that is, the downlink radiation irradiance E 0 The push rod of the movable calibration plate mechanism is also recorded in the collected data. The state of the device during the collection is as follows: Figure 1 As shown in b.

[0043] The bottom quality and two types of uplink and downlink radiation data obtained in step 3) and step 4) are processed and analyzed. According to the specific reference position and reference reflectivity of the movable calibration plate, the influence of the water column between the sensor and the seabed is corrected to obtain the true reflection spectrum of the seabed. Figure 2 The relevant distance and optical parameter information of the instrument when measuring the bottom spectrum are shown, and the reflectivity calculation formula of the bottom is as follows:

[0044] According to the corresponding uplink radiation radiance L when measuring the actual underwater target 1 and downlink radiation irradiance E 1。 The movable calibration plate mechanism pushes the calibration plate to the bottom of the uplink radiation sensor at a vertical distance of d. 1 , the uplink radiation radiance L obtained by the sensor 0 and downlink radiation irradiance E 0。 The direct reflectivity R of the two measurements 0 and R 1 Direct calculation is:

[0045]

[0046]

[0047] Considering the height difference between the uplink and downlink radiation sensors during assembly, 0 , and the distance d between the uplink radiation sensor and the bottom of the water 2 The above direct reflectivity can be corrected according to the Beer-Lambert law to obtain the optical attenuation based on the calibration plate reflectivity R f Get the bottom reflectivity R b :

[0048]

[0049]

[0050] In the above formula, K is the optical attenuation coefficient of the water body, which can be solved or eliminated in this method. b In both measurements it should be calculated as:

[0051]

[0052] Figure 3 The results of the spectral curves of the water column reflectance of the white board and the water column reflectance of the underwater waterweed recorded in the embodiment are shown. It can be seen that the measured reflectance value of the calibration plate with a full-band reflectance of 95% drops to about 40%~50% after water column attenuation. The different reflectances of each band represent the attenuation information of each band. After implementing the corresponding correction algorithm, Figure 4 It shows that the underwater corrected bottom spectrum results in the visible light band are in good agreement with the measurement results of collecting aquatic plants in the air.

[0053] 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 are included in the protection scope of the present invention.

Claims

1. A shallow seabed geological spectrum observation device, characterized in that: The invention comprises a downlink radiation sensor (1), an uplink radiation sensor (2), a tripod landing frame fixing mechanism (3), an underwater camera (4) and a movable calibration plate mechanism (5); the tripod landing frame fixing mechanism (3) comprises an annular bracket and a first support leg, a second support leg and a third support leg fixed to the annular bracket; the annular bracket is provided with a cross beam, and the downlink radiation sensor (1) and the uplink radiation sensor (2) are fixed to the cross beam; the underwater camera (4) is fixed to the first support leg of the tripod landing frame fixing mechanism (3); and the movable calibration plate mechanism (5) is fixed to the second support leg of the tripod landing frame fixing mechanism (3).

2. The shallow seabed geological spectrum observation device according to claim 1, characterized in that: The movable calibration plate mechanism (5) comprises a push rod and a reflectivity calibration white plate, wherein the reflectivity calibration white plate is fixed to one end of the push rod and the other end is fixed to the second leg of the tripod landing frame fixing mechanism (3), and the push rod can be extended and retracted to adjust the position of the reflectivity calibration white plate.

3. The shallow seabed geological spectrum observation device according to claim 1, characterized in that: The downlink radiation sensor (1) and the uplink radiation sensor (2) are spectral measurement instruments with waterproof and pressure-resistant capabilities, and are used to measure the radiation intensity at a specific depth underwater.

4. The shallow seabed geological spectrum observation device according to claim 1, characterized in that: A data collector (6) is provided on the third leg of the tripod landing frame fixing mechanism (3); the data collector (6) is connected to the downlink radiation sensor (1), the uplink radiation sensor (2), the underwater camera (4) and the movable calibration plate mechanism (5) via a waterproof cable.

5. The shallow seabed geological spectrum observation device according to claim 1, characterized in that: The observation device further comprises a control module, which is connected to a data acquisition device (6) via a waterproof cable and is used to control the opening and closing of the downlink radiation sensor (1), the uplink radiation sensor (2), the underwater camera (4) and the pushing out of a movable calibration plate mechanism (5).

6. A method for observing shallow seabed seismic spectra, characterized in that: The method is implemented by using the device according to any one of claims 1 to 5, and the specific steps are as follows: S1. Installing a shallow seabed seismic spectrum observation device and lowering the device through a ship-based platform until the tripod landing frame fixing mechanism (3) lands on the bottom of the water; S2. Observe the underwater target corresponding to the uplink radiation sensor through an underwater camera to determine the location and area of ​​the observation device being lowered; S3. Using the downlink radiation sensor to collect the first environmental spectral data, and using the uplink radiation sensor to collect the spectral data of the bottom reflectance; S4. Controlling the push rod of the movable calibration plate mechanism to push the reflectivity calibration white plate to the bottom of the uplink radiation sensor, collecting the spectral data reflected by the reflectivity calibration white plate through the uplink radiation sensor, and synchronously recording the second environmental spectral data collected by the downlink radiation sensor; S5. Process and analyze the spectral data of the bottom reflection, the spectral data of the reflectance calibration whiteboard reflection, and the environmental spectral data collected twice to obtain the reflectance data of the seabed bottom without the influence of the water column.

7. A shallow seabed geological spectrum observation method according to claim 6, characterized in that: The underwater target corresponding to the upward radiation sensor is observed by the underwater camera to determine the lowering position and area of ​​the observation device. Specifically, the underwater target picture is taken by the underwater camera to observe the bottom type corresponding to the upward radiation sensor to determine whether to measure in the area. Otherwise, it is necessary to adjust the lowering position or move to the next area for measurement through the ship-based platform.

8. A method for observing shallow seabed geological spectra according to claim 6, characterized in that: The reflectivity data of the seabed without the influence of the water column is specifically calculated as follows: based on the spectral data of bottom reflection, the spectral data of the reflectivity calibration whiteboard reflection, the environmental spectral data collected twice, the height difference between the downlink radiation sensor and the uplink radiation sensor, and the distance between the uplink radiation sensor and the water bottom, the optical attenuation is corrected using the Beer-Lambert law to calculate the reflectivity of the seabed without the influence of the water column.

Images