A soil moisture content remote sensing monitoring method

Abstract

The application discloses a kind of soil moisture content remote sensing monitoring methods, comprising: unmanned aerial vehicle gathers the remote sensing image of monitoring area;Base station device receives remote sensing image, analysis determines the bare proportion of soil in remote sensing image;Bare proportion is compared with the set proportion threshold value, determine whether bare proportion is less than proportion threshold value;If bare proportion is less than proportion threshold value, unmanned vehicle is started to go to monitoring area;Unmanned vehicle gathers the soil image in monitoring area;Base station device synthesizes remote sensing image and soil image, forms synthesis image;Synthesis image is analyzed, and the soil moisture content of monitoring area is determined.The method of the application is not affected by ground vegetation coverage, in any case, the information of soil can be obtained, and then the more accurate soil moisture content is determined.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental monitoring, and in particular to a soil moisture content remote sensing monitoring method. BACKGROUND

[0002] Soil moisture content is an important index in agricultural production and ecological environment monitoring, and appropriate soil moisture content can provide a good growing environment for vegetation, thereby promoting the development of the ecological environment or ensuring the quality of agricultural production.

[0003] Because the range to be monitored is very large, satellite remote sensing images are currently used to determine soil moisture content. However, the update cycle of satellite remote sensing images is relatively long, and the resolution cannot completely meet the needs of monitoring. To solve this problem, remote sensing image acquisition technology based on unmanned aerial vehicles has been developed. When soil moisture content data needs to be updated, the unmanned aerial vehicle takes remote sensing images over the monitoring area, and the soil moisture content of the monitoring area can be determined based on the remote sensing images.

[0004] However, whether satellite remote sensing images or unmanned aerial vehicle remote sensing images are used, they are all taken from above, and the soil moisture content is determined by analyzing the images. For areas where the soil is largely exposed, the accuracy is relatively high, but for areas where the vegetation is dense and the soil is completely covered, the image cannot reflect the information of the soil, so the image obtained in this way cannot accurately determine the soil moisture content. SUMMARY

[0005] The embodiments of the present application provide a soil moisture content remote sensing monitoring method to solve the problem that the soil moisture content cannot be accurately determined based on images taken from the air in the prior art.

[0006] In one aspect, the embodiments of the present application provide a soil moisture content remote sensing monitoring method, comprising:

[0007] The unmanned aerial vehicle collects remote sensing images of the monitoring area;

[0008] The base station device receives the remote sensing images, analyzes and determines the exposure ratio of the soil in the remote sensing images;

[0009] The exposure ratio is compared with a set ratio threshold value to determine whether the exposure ratio is less than the ratio threshold value;

[0010] If the exposure ratio is less than the ratio threshold value, the unmanned vehicle is started to go to the monitoring area;

[0011] The unmanned vehicle collects soil images in the monitoring area;

[0012] The base station device synthesizes the remote sensing images and the soil images to form a synthesized image;

[0013] The synthetic image is analyzed to determine the soil moisture content of the monitoring area.

[0014] In a possible implementation, if the bare ratio is greater than or equal to the ratio threshold, the base station device analyzes the remote sensing image to determine the soil moisture content of the monitoring area.

[0015] In a possible implementation, the base station device receives the remote sensing image, and analyzes and determines the bare ratio of the soil in the remote sensing image, including: the base station device receives the remote sensing image; analyzing the pixels in the remote sensing image, and classifying the vegetation pixels in the remote sensing image; determining the proportion of vegetation pixels in the remote sensing image to obtain the vegetation coverage ratio; and determining the bare ratio of the soil according to the vegetation coverage ratio.

[0016] In a possible implementation, after determining that the bare ratio is less than the ratio threshold, the base station device further determines a vegetation area in the remote sensing image, selects a plurality of collection points in the vegetation area, and then starts the unmanned vehicle to go to the collection points and collect soil images.

[0017] In a possible implementation, when the base station device synthesizes the remote sensing image and the soil image, the soil image collected by the unmanned vehicle at each collection point is overlaid on the vegetation area in the remote sensing image corresponding to the collection point.

[0018] In a possible implementation, the bottom of the unmanned vehicle is provided with a shading cylinder, and the inside of the shading cylinder is provided with an image collection unit and a light supplement unit. When the unmanned vehicle collects the soil image, the shading cylinder is lowered so that the bottom of the shading cylinder is inserted into the soil. After the soil is lighted by the light supplement unit, the image collection unit collects the soil image.

[0019] In a possible implementation, the top of the unmanned vehicle is further provided with an illumination sensor for collecting illumination. The unmanned vehicle controls the brightness of the light supplement unit according to the illumination.

[0020] In a possible implementation, the top of the base station device is provided with a landing platform, and the landing platform is provided with a top charging unit. The unmanned aerial vehicle also monitors the remaining power in real time. When the remaining power is lower than an alarm value, the unmanned aerial vehicle lands on the landing platform and is charged by the top charging unit.

[0021] In a possible implementation, the bottom of the base station device is provided with a bottom charging unit, and the tail of the base station device is provided with a tail plate. The unmanned vehicle also monitors the remaining power in real time. When the remaining power is lower than an alarm value, the base station device lowers the tail plate, the unmanned vehicle enters the base station device through the tail plate, and is charged by the bottom charging unit.

[0022] The soil moisture content remote sensing monitoring method in the application has the following advantages:

[0023] First, the unmanned aerial vehicle collects remote sensing images of the monitoring area. If the exposed soil in the remote sensing images is too little, that is, the vegetation coverage is too much, then the unmanned vehicle collects soil images of the vegetation coverage area. The soil water content of the monitoring area can be determined by combining the remote sensing images and the soil images. The method of the present application is not affected by the ground vegetation coverage. In any case, the soil information can be obtained, and the more accurate soil water content can be determined. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application. Those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0025] Figure 1 A flowchart of a soil water content remote sensing monitoring method provided by an embodiment of the present application;

[0026] Figure 2 The schematic diagrams of the base station device, the unmanned aerial vehicle and the unmanned vehicle provided by the embodiment of the present application.

[0027] Explanation of reference numerals: 200-base station device, 210-landing platform, 220-tail plate, 300-unmanned aerial vehicle, 400-unmanned vehicle, 410-image acquisition unit. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0029] Figure 1 A flowchart of a soil water content remote sensing monitoring method provided by an embodiment of the present application. The present application provides a soil water content remote sensing monitoring method, which includes the following steps:

[0030] S100, the unmanned aerial vehicle 300 collects remote sensing images of the monitoring area.

[0031] Exemplarily, the unmanned aerial vehicle 300 preferably adopts a rotary-wing unmanned aerial vehicle, which can be powered by a battery or a fuel engine. The remote sensing images can be visible light images, infrared images, etc. Correspondingly, a device capable of collecting the required images needs to be installed on the unmanned aerial vehicle 300.

[0032] S110, the base station device 200 receives a remote sensing image, and analyzes to determine the bare proportion of soil in the remote sensing image.

[0033] Exemplarily, the base station device 200 can adopt a vehicle that can move on the ground, for example, a manned vehicle or an unmanned vehicle, which is provided with an antenna capable of communicating with the unmanned aerial vehicle 300 and a processing unit for processing data.

[0034] In the determination of the bare proportion, S110 specifically includes: the base station device 200 receives a remote sensing image; analyzing the pixels in the remote sensing image, classifying the vegetation pixels in the remote sensing image; determining the proportion of vegetation pixels in the remote sensing image to obtain the vegetation coverage proportion; and determining the bare proportion of soil according to the vegetation coverage proportion.

[0035] Since there is a large difference in color between soil and vegetation under visible light, the color of each pixel, also known as pixel, in the remote sensing image can be analyzed, the pixel color is biased towards the color of vegetation, for example, the green pixel is selected, the area where a plurality of vegetation pixels belong is connected to obtain the vegetation area, and the number of pixels in the vegetation area is divided by the number of all pixels in the remote sensing image to obtain the proportion of vegetation pixels in the remote sensing image, that is, the vegetation coverage proportion. After determining the vegetation coverage proportion, subtracting 1 from the vegetation coverage proportion can obtain the bare proportion of soil.

[0036] Although there are other areas such as rivers, lakes, buildings, etc. in the remote sensing image in addition to the vegetation area and the soil area, the proportion of these areas is not large, if higher monitoring accuracy is required in actual monitoring, and the monitoring personnel considers that the influence of other areas in the remote sensing image is large, a template image containing the position information of these other areas can be preset, and the base station device 200 can remove the other areas in the remote sensing image according to the template image after obtaining the remote sensing image to obtain a remote sensing image containing only the vegetation area and the soil area.

[0037] S120, comparing the bare proportion with a set proportion threshold value to determine whether the bare proportion is less than the proportion threshold value.

[0038] Exemplarily, the proportion threshold value is a proportion data set by the monitoring personnel, for example, it can be 70% or 80%, when the bare proportion is less than the proportion threshold value, it means that the area of bare soil in the monitoring area is too small, that is, the area occupied by the vegetation area is too large, at this time the remote sensing image cannot reflect the information of the soil, and the soil water content cannot be determined according to the remote sensing image.

[0039] S130, if the bare proportion is less than the proportion threshold value, the unmanned vehicle 400 is started to go to the monitoring area.

[0040] Exemplarily, if the bare ratio is greater than or equal to the ratio threshold, the base station device 200 analyzes the remote sensing image to determine the soil water content of the monitoring area.

[0041] After determining that the bare ratio is less than the ratio threshold, the base station device 200 further determines the vegetation area in the remote sensing image, selects a plurality of collection points in the vegetation area, and then starts the unmanned vehicle 400 to go to the collection points and collect soil images. For each independent vegetation area, i.e. not connected with other vegetation areas, a corresponding number of collection points can be selected according to the size of the area to ensure the density of the collection points in the vegetation area.

[0042] In the embodiment of the present application, after the base station device 200 selects the collection points, the positions of the collection points are converted into latitude and longitude coordinates, which are then sent to the unmanned vehicle 400. The unmanned vehicle 400 is provided with a positioning unit for real-time acquisition of the position of the unmanned vehicle 400. After receiving the latitude and longitude coordinates of the collection points sent by the base station device 200, the unmanned vehicle 400 starts to move and go to the collection points.

[0043] S140, the unmanned vehicle 400 collects soil images in the monitoring area.

[0044] Exemplarily, the bottom of the unmanned vehicle 400 is provided with a shading cylinder, and the inside of the shading cylinder is provided with an image collection unit 410 and a light supplement unit. When the unmanned vehicle 400 collects soil images, the shading cylinder is lowered so that the bottom of the shading cylinder is inserted into the soil. After the soil is lighted by the light supplement unit, the image collection unit 410 collects soil images.

[0045] The shading cylinder can be arranged at the bottom of the unmanned vehicle 400 in a telescopic or lifting manner. When the unmanned vehicle 400 moves, the shading cylinder can be raised to avoid the influence of contact with the ground on the movement of the unmanned vehicle 400. When the unmanned vehicle 400 moves to the collection point, the shading cylinder is lowered. Since the unmanned vehicle 400 will affect the light of the soil below, and the influence will change with the surrounding environment, the present application uses a light-tight shading cylinder to isolate the external light, and uses a light supplement unit to light the soil surface, so that the image collection unit 410 can collect uniform and high-quality soil images. Since the images collected by the unmanned vehicle 300 can be visible light images, infrared images, etc., the image collection unit 410 arranged on the unmanned vehicle 400 can also collect these types of images.

[0046] Further, the top of the unmanned vehicle 400 is also provided with a light sensor for collecting illuminance, and the unmanned vehicle 400 controls the brightness of the light supplement unit according to the illuminance.

[0047] Due to the shielding of natural light by the unmanned vehicle 400, the soil under natural light cannot be completely simulated by the fixed brightness light supplement unit. Therefore, the light sensor is used to collect the light brightness of the external environment, and then the light supplement unit generates the same brightness as the natural light. Moreover, the light supplement unit preferably uses a full-spectrum lamp with a spectrum close to that of natural light to simulate the illumination of the soil under natural light, thereby obtaining a soil image close to the real situation.

[0048] In S150, the base station device 200 synthesizes the remote sensing image and the soil image to form a synthesized image.

[0049] For example, when the base station device 200 synthesizes the remote sensing image and the soil image, the soil image collected by the unmanned vehicle 400 at each collection point is overlaid in the vegetation area corresponding to the collection point on the remote sensing image.

[0050] Since the size of the soil image is likely to be smaller than the area of the vegetation area, the multiple soil images can be spliced and cropped according to the shape and size of the vegetation area after splicing to obtain a soil image conforming to the shape and size of the vegetation area, which can then be overlaid on the corresponding vegetation area. In the synthesized image, all the information of the soil can be reflected.

[0051] In the embodiments of the present application, since the soil images collected in the same vegetation area can be more than one, the soil images collected in the same vegetation area can be divided according to the positions of the collection points, and the soil images collected in the same vegetation area can be spliced and overlaid according to the positions of the collection points. Further, the remote sensing image and the soil image used in the synthesis are of the same type, i.e., both are visible light images or both are infrared images.

[0052] In S160, the synthesized image is analyzed to determine the soil water content of the monitoring area.

[0053] For example, the synthesized image in the form of thermal infrared can be used to deduce the soil temperature, and then the soil heat capacity can be determined according to the soil temperature, and finally the soil water content can be determined according to the soil heat capacity.

[0054] Further, as Figure 2As shown, when the unmanned aerial vehicle 300 and the unmanned vehicle 400 are both powered by batteries, there may be a need for charging, and if the unmanned aerial vehicle 300 and the unmanned vehicle 400 are returned to a fixed charging position, more time is required, therefore the base station device 200 is used as a charging device, and a plurality of batteries are arranged inside the base station device 200. Meanwhile, the top of the base station device 200 is provided with a landing platform 210, and the landing platform 210 is provided with a top charging unit. The unmanned aerial vehicle 300 also monitors the remaining power in real time, and when the remaining power is lower than the warning value, the unmanned aerial vehicle 300 lands on the landing platform 210 and is charged by the top charging unit.

[0055] Further, the bottom of the base station device 200 is provided with a bottom charging unit, and the tail of the base station device 200 is provided with a tail plate 220. The unmanned vehicle 400 also monitors the remaining power in real time, and when the remaining power is lower than the warning value, the base station device 200 lowers the tail plate 220, the unmanned vehicle 400 enters the base station device 200 through the tail plate 220, and is charged by the bottom charging unit.

[0056] The top charging unit and the bottom charging unit can adopt the mode of extending metal contacts or contacts, and the lower end is connected with the battery inside the base station device 200. When the metal contacts at the bottom of the unmanned aerial vehicle 300 or the unmanned vehicle 400 are in contact with it, the charging circuit is connected, and the unmanned aerial vehicle 300 and the unmanned vehicle 400 are charged.

[0057] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0058] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for remote sensing monitoring of soil moisture content, characterized in that, include: The UAV (300) collects remote sensing images of the monitoring area; The base station device (200) receives the remote sensing image and analyzes it to determine the proportion of exposed soil in the remote sensing image; The exposed ratio is compared with a set ratio threshold to determine whether the exposed ratio is less than the ratio threshold; If the exposed ratio is less than the ratio threshold, the unmanned vehicle (400) is activated to proceed to the monitoring area; The unmanned vehicle (400) collects soil images in the monitoring area; The base station device (200) combines the remote sensing image and the soil image to form a composite image; The synthesized image is analyzed to determine the soil moisture content of the monitored area.

2. The method for remote sensing monitoring of soil moisture content according to claim 1, characterized in that, If the exposed ratio is greater than or equal to the ratio threshold, the base station device (200) analyzes the remote sensing image to determine the soil moisture content of the monitoring area.

3. The method for remote sensing monitoring of soil moisture content according to claim 1, characterized in that, The base station device (200) receives the remote sensing image and analyzes and determines the proportion of exposed soil in the remote sensing image, including: The base station device (200) receives the remote sensing image; The pixels in the remote sensing image are analyzed, and the vegetation pixels in the remote sensing image are classified. Determine the proportion of the vegetation pixels in the remote sensing image to obtain the vegetation coverage ratio; The proportion of exposed soil is determined based on the vegetation cover ratio.

4. The method for remote sensing monitoring of soil moisture content according to claim 1, characterized in that, After determining that the exposed ratio is less than the ratio threshold, the base station device (200) further determines the vegetation area in the remote sensing image, selects multiple collection points in the vegetation area, and then starts the unmanned vehicle (400) to go to the collection point and collect the soil image.

5. The method for remote sensing monitoring of soil moisture content according to claim 4, characterized in that, When the base station device (200) synthesizes the remote sensing image and the soil image, it overlays the soil image collected by the unmanned vehicle (400) at each collection point onto the vegetation area corresponding to the collection point on the remote sensing image.

6. The method for remote sensing monitoring of soil moisture content according to claim 1, characterized in that, The unmanned vehicle (400) is equipped with a shield tube at the bottom. Inside the shield tube are an image acquisition unit (410) and a supplementary lighting unit. When the unmanned vehicle (400) acquires the soil image, the shield tube is lowered so that the bottom of the shield tube is inserted into the soil. After the supplementary lighting unit provides supplementary lighting to the soil, the image acquisition unit (410) acquires the soil image.

7. The method for remote sensing monitoring of soil moisture content according to claim 6, characterized in that, The unmanned vehicle (400) is also equipped with a light sensor on its top. The light sensor is used to collect illuminance, and the unmanned vehicle (400) controls the brightness of the supplementary lighting unit according to the illuminance.

8. The method for remote sensing monitoring of soil moisture content according to claim 1, characterized in that, The base station device (200) is provided with a landing platform (210) on top, and a top charging unit is provided in the landing platform (210). The drone (300) also monitors the remaining power in real time. When the remaining power is lower than the warning value, the drone (300) lands on the landing platform (210) and charges through the top charging unit.

9. The method for remote sensing monitoring of soil moisture content according to claim 1, characterized in that, The base station device (200) is equipped with a bottom charging unit at its bottom and a tail plate (220) at its rear. The unmanned vehicle (400) also monitors the remaining power in real time. When the remaining power is lower than the warning value, the base station device (200) lowers the tail plate (220), and the unmanned vehicle (400) enters the base station device (200) through the tail plate (220) and charges through the bottom charging unit.

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