Low-cost forest crown canopy density dynamic automatic monitoring device

Abstract

The utility model relates to a low-cost dynamic automatic monitoring device for canopy density of a forest crown, which comprises a tripod, a protection box arranged on the tripod, and a trap camera, a magnetic compass, a gradienter and the like which are arranged in the protection box, and a leveler for adjusting levelness is arranged at the positions of the tripod and a bottom plate of the protection box; a transparent hemispherical cover is arranged above the protection box, an adaptive ring is arranged in the middle, and an adaptive base plate is arranged below the protection box. Compared with the existing digital hemisphere photography technology, the technical scheme of the utility model can automatically run for a long time under the field condition, and is popularized based on the practical scene of the trap camera of the existing mature technology, so that the investment cost of the whole system is greatly reduced.

Description

Technical Field

[0001] The utility model relates to a forest crown canopy closure monitoring device, in particular to a low-cost forest crown canopy closure dynamic automatic monitoring device. Background Art

[0002] Canopy closure refers to the proportion of the sky hemisphere blocked by the plant canopy observed at a certain point. It can directly reflect the proportion of transmitted light in the forest at the observation point and indirectly indicate the light environment under the forest. It is an important indicator for describing habitat characteristics in ecological and forestry research.

[0003] The canopy closure can be measured by visual estimation or digital hemispherical photography. Among them, the visual estimation method, which is currently widely used due to its simplicity of operation, mainly relies on the subjective experience of the observer to estimate the canopy closure. Serious systematic errors may occur between different observers. Therefore, the data obtained by the visual estimation method when applied to long-term monitoring may be very unstable.

[0004] Digital hemispherical photography (DHP) is currently recognized as a standard method that can objectively and quantitatively measure canopy closure and leaf area index. This method uses a digital camera with a wide-angle lens to take field photos of the sky occlusion, thereby obtaining relatively accurate canopy closure and further calculating the leaf area index through multi-angle gap ratio. Since this method can permanently record the canopy structure at the time of shooting through images, and in principle is closest to the expression of canopy closure, it is considered to be the best choice for indirect measurement of canopy structure and has been widely used in research in the field of ecology. However, since this method is limited by exposure conditions such as sky background and shooting time, and has certain requirements for specific performance of equipment such as waterproof and dustproof when used for long-term field monitoring, the sky hemispherical photography equipment currently used for canopy closure observation is mostly carried out manually, and there are obvious deficiencies in the monitoring time frequency and monitoring range; the few professional customized equipment on the market generally have the problem of too high customization cost, which is difficult to promote in large quantities in the long-term monitoring process of forest ecology.

[0005] Camera traps are a technology for monitoring wildlife that has gained popularity in recent years. Since wildlife monitoring requires equipment to work for long periods of time in harsh outdoor environments, most cameras with trap trigger functions currently available on the market have high protection performance. The replaceable built-in battery pack can support the camera to work independently in the wild for more than a year. Many models can support real-time data transmission, and some models also have built-in satellite positioning functions. Most of these trap cameras support multiple trigger modes such as infrared triggering and timed triggering.

[0006] Since digital hemispherical photography is essentially based on exposing and imaging the sky, this method has strict requirements on sky conditions when shooting. When the light is too dark, the photo may be underexposed and the contrast of the photo is insufficient, and the canopy closure cannot be calculated. Therefore, this method cannot be implemented at night or in an environment with too little light. When shooting during the day, if the sun appears directly in the camera's field of view, the area around the sun in the photo will be overexposed, which may lead to an underestimation of the canopy closure. Therefore, hemispherical photography technology requires the necessary support of camera hardware that can set multiple timed shooting times and has a high level of field protection.

[0007] Trap cameras are low-cost and have a high level of protection in the wild. Trap cameras with real-time transmission functions can even transmit data back and generate real-time data reports through the automated background software processing system. However, all current trap cameras are mainly aimed at working scenes with horizontal or oblique vision, and do not consider the protection needs when shooting the sky. The concave lens design will cause water accumulation in the lens when installed with the camera looking up. Therefore, it is necessary to make necessary improvements to the equipment to meet the strict requirements of hemispherical photogrammetry technology for shooting angles. Utility Model Content

[0008] The purpose of this utility model is to overcome the shortcomings of the above-mentioned prior art and provide a low-cost dynamic automatic monitoring device for forest canopy closure. By customizing and integrating a small number of necessary accessories, taking hemispherical photography technology as the main theoretical basis and mature trap cameras as the main technical basis, a low-cost long-term dynamic monitoring device for forest canopy closure that can operate independently in the wild for a long time is designed to achieve low-cost all-weather dynamic automatic monitoring of forest canopy closure.

[0009] The technical solution of the utility model is:

[0010] A low-cost dynamic automatic monitoring device for forest canopy closure consists of a tripod, a protective box installed on the tripod, a trap camera, a magnetic compass and a level arranged inside the protective box, and a leveler for adjusting the horizontality is arranged between the tripod and the bottom plate of the protective box; a transparent hemispherical cover is provided on the top of the protective box, an adapter ring is provided in the middle, and an adapter pad is provided at the bottom.

[0011] The trap camera contains a digital camera and a wide-angle lens. The trap camera has a built-in timed trigger shooting program for collecting, storing and transmitting photos, and has necessary waterproof and dustproof properties. The trap camera works in a timed mode. Every day, before and after the sun enters the camera's field of view (generally before 8:00 and after 16:00 local time), the sky is photographed through the camera's timed shooting function to avoid the sun entering the camera's field of view and affecting the calculation results of the canopy closure as much as possible. Generally, at least one photo is taken before (but not limited to) 8:00 local time and after 16:00 local time. After shooting, the photos are stored in the camera's built-in SD card, and can be transmitted back to the computer of the internal monitoring component through the wide area network or local area network through the transmission module of the trap camera itself, or the photos in the SD card can be read manually on site.

[0012] The magnetic compass is used to ensure that the upper direction of the photo obtained when the camera is installed points to the true north, or other specified directions.

[0013] The transparent hemispherical cover ensures basic waterproof and drainage requirements when the camera lens is aligned, and ensures that the camera imaging does not suffer obvious distortion. The transparent hemispherical cover is adjusted in height by an adapter ring arranged at the bottom so that the center position of the sphere overlaps with the camera lens position, which can reduce the influence of possible refraction between different media when light passes through the transparent cover.

[0014] The level is used to indicate the horizontality, which indirectly reflects whether the lens of the trap camera is pointing in a vertical upward shooting state (the zenith angle is 0°).

[0015] The tripod is used to ensure that the entire system does not move significantly during long-term field operation. The transparent dome cover and the tripod are connected by an adapter plate, which has certain waterproof and dustproof properties and can be opened and closed to facilitate necessary maintenance of the camera.

[0016] The beneficial effects of the utility model include:

[0017] Compared with the existing digital hemispherical photography technology, the technical solution of the utility model can automatically operate for a long time under field conditions. Since it is a practical scene promotion of trap cameras based on existing mature technology, the investment cost of the entire system is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 : Schematic diagram of the composition of the utility model, in the figure: 11-tripod, 12-protection box, 13-trap camera, 14-magnetic compass, 15-level meter, 121-transparent hemispherical cover, 122-adapter ring, 123-adapter pad, 2-computer. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, as an implementation mode, the utility model is a low-cost dynamic automatic monitoring device for canopy closure, which consists of a tripod 11, a protective box 12 installed on the tripod 11, and a trap camera 13, a magnetic compass 14 and a level 15 arranged inside the protective box 12; the protective box 12 consists of an adapter pad 123, an adapter ring 122 and a transparent hemispherical cover 121 from bottom to top; the adapter pad 123 is a circular thin plate, which is fixedly connected to the adapter ring 122 from below in a detachable manner; the diameter of the transparent hemispherical cover 121 is slightly larger than the diameter of the adapter ring 122, and the adapter ring 122 is fixedly connected to the transparent hemispherical cover 121 from below in a detachable manner; the tripod 11 is fixedly connected to the adapter pad 123 of the protective box 12 in a detachable manner.

[0021] The trap camera 13 has a built-in battery and a wireless network communication unit, and can choose to wirelessly communicate with a remote computer 2. The computer 2 can read the photos taken at regular intervals by the trap camera 13, and can also obtain the photos taken at regular intervals by manually reading the SD card of the trap camera 13 on site.

[0022] The one side of the adapter ring 122 and the adapter pad 123 located in the protection box 12 is a dark matte surface for preventing glare.

[0023] The trap camera 13 contains a digital camera and a wide-angle lens. The trap camera 13 has a built-in timing trigger shooting program for collecting, storing and transmitting photos, and has necessary waterproof and dustproof properties. The trap camera 13 works in a timing mode. Every day, before and after the sun enters the camera's field of view (before 8:00 and after 16:00 local time), the camera's timing shooting function takes a picture of the sky to avoid the sun entering the camera's field of view and affecting the calculation result of the canopy closure as much as possible. Generally, at least one picture is taken before (but not limited to) 8:00 and after 16:00 local time. After shooting, the photos are stored in the camera's built-in SD card, or transmitted back to the computer of the internal monitoring component through the wide area network or local area network through the camera's built-in transmission module.

[0024] The magnetic compass 14 is used to ensure that the upper direction of the photo taken when the camera is installed points to the true north, or other specified directions.

[0025] The transparent hemispherical cover 121 ensures basic waterproof and drainage requirements when the camera lens is aligned, and at the same time ensures that the camera imaging does not suffer from obvious distortion.

[0026] The height of the transparent hemispherical cover 121 and the adapting pad 123 is adjusted by the height of the adapting ring 122 sleeved thereunder, so that the center position of the sphere overlaps with the position of the camera lens mounted on the adapting pad 123, thereby reducing the influence of possible refraction between different media when light passes through the transparent cover. The adapting ring 122 is a section of PVC pipe.

[0027] The tripod 11 is used to ensure that the entire system does not undergo obvious displacement during long-term field operation. The tripod 11 is also provided with a horizontal adjustment mechanism. By observing the spirit level 15 and adjusting the legs and / or the horizontal adjustment mechanism of the tripod 11, the direction of the lens of the trap camera 13 can be adjusted to a vertically upward shooting state (zenith angle is 0°).

[0028] The protection box 12 is waterproof and dustproof, and the protection box 12 can be opened by opening the transparent hemispherical cover 121, so as to take out the memory card of the camera or perform necessary maintenance on the camera.

[0029] Remote computer 2 runs existing or customized image analysis software (such as CAN-EYE), processes the photos transmitted in real time or downloaded regularly based on known information such as camera focal length, image sensor size and lens field of view, and calculates the canopy closure and leaf area index in the photos.

Claims

1. A low-cost automatic monitoring device for dynamic canopy density, characterized in that: The device comprises a tripod (11), a protection box (12) mounted on the tripod (11), and a trap camera (13), a magnetic compass (14) and a level (15) arranged inside the protection box (12); the protection box (12) comprises, from bottom to top, an adapting pad (123), an adapting ring (122) and a transparent hemispherical cover (121); the adapting pad (123) is a circular thin plate, which is detachably connected to the adapting ring (122) from the bottom. The transparent hemispherical cover (121) is fixedly connected in a manner; the diameter of the transparent hemispherical cover (121) is slightly larger than the diameters of the adapting pad (123) and the adapting ring (122); the adapting ring (122) is fixedly connected to the transparent hemispherical cover (121) from below the transparent hemispherical cover (121) in a detachable manner; the tripod (11) is fixedly connected to the adapting pad (123) of the protective box (12) in a detachable manner; the trap camera (13) contains a digital camera and a wide-angle lens for collecting and storing photos.

2. A low-cost automatic monitoring device for dynamic canopy closure according to claim 1, characterized in that: The height of the transparent hemispherical cover (121) and the adapting pad (123) is adjusted by the height of the adapting ring (122) sleeved thereunder, so that the center position of the sphere overlaps with the position of the camera lens mounted on the adapting pad (123).

3. A low-cost automatic monitoring device for dynamic canopy density according to claim 1, characterized in that: The tripod (11) is also provided with a horizontal adjustment mechanism, and the lens direction of the trap camera (13) is adjusted to a vertical upward shooting state by observing the level meter (15) and adjusting the legs of the tripod (11) and / or the horizontal adjustment mechanism.

4. The low-cost automatic monitoring device for dynamic canopy density according to claim 1, characterized in that: One side of the adapting pad (123) located inside the protection box (12) is a dark matte surface, which is used to prevent glare.

5. The low-cost automatic monitoring device for dynamic canopy closure according to claim 1 is characterized in that: The protection box (12) has waterproof and dustproof properties, and the protection box (12) can be opened by opening the transparent hemispherical cover (121).

6. The low-cost automatic monitoring device for dynamic canopy density according to claim 1, characterized in that: The magnetic compass (14) is used to ensure that the upper direction of the photo obtained when the camera is installed points to the true north, or other specified directions.

7. The low-cost automatic monitoring device for dynamic canopy density according to claim 1, characterized in that: The trap camera (13) is also equipped with a built-in battery and a wireless network communication unit, and is capable of wirelessly communicating with a remote computer (2) to transmit the photos taken by the trap camera (13) at regular intervals to the computer (2).

8. A low-cost automatic monitoring device for dynamic canopy density according to any one of claims 1 to 7, characterized in that: The adapter ring (122) is a section of PVC pipe.

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