WO2022092436A1

WO2022092436A1 - System for measuring river topography by using drone, and method therefor

Info

Publication number: WO2022092436A1
Application number: PCT/KR2020/018919
Authority: WO
Inventors: 성호제; 이동섭; 신재현
Original assignee: 한국건설기술연구원
Priority date: 2020-10-30
Filing date: 2020-12-22
Publication date: 2022-05-05
Also published as: KR102297661B1

Abstract

A system for measuring river topography by using a drone, and a method, according to an embodiment therefor, are disclosed. The river topography measurement system comprises: a mobile device, which has a LIDAR and a hyperspectral sensor mounted thereon, acquires distance information by using the LIDAR while flying over a river area including protected lowland and riverside land, and acquires a hyperspectral image by using the hyperspectral sensor; and a relay device for calculating two-dimensional planar river topography information about the river area as a result analyzed by receiving the distance information and the hyperspectral image, while moving along the river area according to the flight of the mobile device.

Description

System and method for surveying river topography using drone

The embodiment relates to a system and method for surveying a river topography using a drone.

Currently, for river surveys, surveyors such as total stations and echo sounders and measuring instruments such as velocity gauges, water level gauges, and water quality meters are directly operated by the investigator at the site to acquire river information.

Some devices, such as water level gauges and water quality meters, use a communication network to install devices on site and then obtain information remotely. it costs

In addition, the efficiency of river investigation and utilization of river information is very low because only specific point information where the measuring device is installed among river sections with a wide spatial range can be checked.

The embodiment may provide a system and a method for surveying a river topography using a drone.

The river topography surveying system according to the embodiment is equipped with a lidar and a hyperspectral sensor, acquires distance information using the lidar while flying in a river area including the jean and excluding regions, and uses the hyperspectral sensor to acquire distance information. a mobile device for acquiring a spectroscopic image; And while moving along the river region according to the flight of the mobile device, a relay device that receives the distance information and the hyperspectral image and calculates two-dimensional planar river topography information for the river region as a result of analysis. can

The mobile device obtains distance information using a first laser signal and a second laser signal having different wavelengths of the lidar, and obtains distance information around a river using the first laser signal, and the second laser By using the signal, it is possible to obtain distance information of the river bed.

The first laser signal may be a near infrared laser signal, and the second laser signal may be a green laser signal.

The relay device calculates first river topography information using the distance information, calculates second river topography information using the hyperspectral image, and calculates the first river topography information and the second river topography information can be matched.

The relay device extracts a first matching criterion from the first river topography information, extracts a second matching criterion from the second river topography information, and the extracted first matching criterion and the second matching criterion coincide with each other The first river topography information and the second river topography information may be matched to make the same.

The relay device extracts a first river edge from the first river topography information, extracts the first matching criterion from the extracted first river edge, and a second river edge from the second river topography information may be extracted, and the second matching criterion may be extracted from the extracted second edge of the river.

In the river topography surveying method according to the embodiment, a mobile device equipped with a lidar and hyperspectral sensor acquires distance information using the lidar while flying in a river area including the jean and excluding regions, and uses the hyperspectral sensor to obtain a hyperspectral image; and calculating two-dimensional planar river topography information for the river region as a result of the relay device receiving and analyzing the distance information and the hyperspectral image while moving along the river region according to the flight of the mobile device. may include

According to the embodiment, using the lidar and hyperspectral sensor mounted on the drone, the river bottom topography information is calculated using the distance information obtained from the lidar, and the river using the hyperspectral image acquired from the hyperspectral sensor By calculating the surrounding topographical information and matching the riverbed topographical information with the riverside topographical information, it is possible to efficiently investigate the river topography, breaking away from the manpower-oriented on-site direct measurement method.

According to the embodiment, compared with the existing river topography surveying method, it is possible to obtain two-dimensional planar topography information with high continuity and precision, as well as the expansion of the survey section and efficient management of the topographic information of the river.

According to the embodiment, since it is possible to omit the reference to the expression point required to correct the error of the information measured on the topography around the river and the topography of the river bed due to the direct measurement of the river investigator, the manpower required for the topographic survey of the entire section of the river It can greatly reduce the cost.

1 is a view showing a system for managing a river according to an embodiment of the present invention.

2 is a diagram for explaining a case in which a mobile device and a relay device move.

FIG. 3 is a diagram showing a detailed configuration of the mobile device shown in FIG. 1 .

FIG. 4 is a diagram showing a detailed configuration of the relay device shown in FIG. 1 .

5 is a first diagram illustrating a river topography measurement process according to an embodiment of the present invention.

6 is a view for explaining the river topography measurement principle shown in FIG. 5 .

7 is a second diagram illustrating a river topography measurement process according to an embodiment of the present invention.

FIG. 8 is a diagram illustrating the process of matching the river topography shown in FIG. 7 .

9 is a view for explaining the river topography measurement principle shown in FIG. 7 .

FIG. 10 is a view for explaining the river topography matching principle shown in FIG. 7 .

11 is a diagram illustrating a process of measuring river characteristic information according to an embodiment of the present invention.

12 is a view showing a river facility recognition process according to an embodiment of the present invention.

13 is a view for explaining the river facility recognition principle shown in FIG. 12 .

14 is a diagram illustrating a method for managing a river according to an embodiment of the present invention.

15A to 15B are diagrams comparing system performance according to whether a relay device is operated.

16 is a diagram for explaining a mission scenario derivation technique according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical spirit of the present invention is not limited to some embodiments described, but may be implemented in various different forms, and within the scope of the technical spirit of the present invention, one or more of the components may be selected between the embodiments. It can be used by combining or substituted with .

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be generally understood by those of ordinary skill in the art to which the present invention belongs, unless specifically defined and described explicitly. It may be interpreted as a meaning, and generally used terms such as terms defined in advance may be interpreted in consideration of the contextual meaning of the related art.

In addition, the terminology used in the embodiments of the present invention is for describing the embodiments and is not intended to limit the present invention.

In this specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when it is described as “at least one (or more than one) of A and (and) B, C”, it is combined with A, B, and C It may include one or more of all possible combinations.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

These terms are only for distinguishing the component from other components, and are not limited to the essence, order, or order of the component by the term.

And, when it is described that a component is 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also with the component It may also include a case of 'connected', 'coupled' or 'connected' due to another element between the other elements.

In addition, when it is described as being formed or disposed on “above (above) or under (below)” of each component, the top (above) or bottom (below) is one as well as when two components are in direct contact with each other. Also includes a case in which another component as described above is formed or disposed between two components. In addition, when expressed as “upper (upper) or lower (lower)”, the meaning of not only the upward direction but also the downward direction based on one component may be included.

In the embodiment, the lidar and hyperspectral sensor mounted on the drone are used, but the river bottom topography information is calculated using the distance information obtained from the lidar, and the hyperspectral image obtained from the hyperspectral sensor is used to surround the river We propose a new method that calculates topographical information and combines the topographical information of the river bed with the topographical information around the river to calculate the two-dimensional planar topographical information for the area to be investigated including the inlet and excluded areas. Here, je-nae refers to the area protected by the river embankment, that is, to the village protected from the embankment.

Referring to FIG. 1 , a system for managing a river according to an embodiment of the present invention may include a mobile device 100 , a relay device 200 , an integrated server 300 , and a DB (Database) 400 . .

The mobile device 100 may fly in an investigation target area that is a partial area or an entire area of a river, and may measure and transmit the first river information and the second river information. The mobile device 100 may be, for example, an unmanned aerial vehicle (UAV) capable of autonomous driving.

Here, the first river information may be non-image information for analyzing water depth, surrounding topography, etc., and the second river information may be image information for analyzing water depth, water quality, flow velocity, floating sand, and the like.

The mobile device 100 may measure and transmit the first river information and the second river information while flying according to a predetermined flight altitude, flight path, and flight speed within the investigation target area. In this case, the area to be irradiated may be one area or divided into a plurality of areas.

Here, a case in which one mobile device 100 is used is described as an example, but the present invention is not limited thereto, and a plurality of mobile devices 100 may be used. For example, two mobile devices can be used to measure river information in different areas.

The relay device 200 interworks with the mobile device 100, receives first and second river information measured from the mobile device 100, and based on the received first and second river information It is possible to build a river information DB for the area to be investigated.

For example, the relay device 200 analyzes the first river information to calculate the water depth, surrounding topography, etc. for the investigation target area, and analyzes the second river information to analyze the water depth, water quality, flow velocity, floating sand, etc. for the investigation target area can be calculated to build a river information DB.

The relay device 200 may move according to the movement of the mobile device 100 . For example, when the area to be irradiated is divided into a plurality of areas, the relay apparatus 200 may move together as the mobile apparatus 100 moves after the measurement is completed for each of the plurality of areas.

The relay device 200 may be installed in a vehicle to move together while maintaining a predetermined distance as the mobile device 100 moves along a river, and may be driven as a mobile relay device.

The relay device 200 may receive information on the flight altitude, flight path, and flight speed of the mobile device 100 according to a user's manipulation, and may provide the input information to the mobile device 100 .

Here, the relay device 200 is described as an example of a device mounted on a vehicle, but the present invention is not limited thereto and may be a moving object capable of autonomous flight, such as a mobile device.

Referring to FIG. 2 , when the mobile device moves to the first region within the investigation target region and measures river information in the first region, the relay device may move along the mobile device in the first region.

In this case, the relay device may move along with the mobile device based on a predetermined time.

The integrated server 300 may interwork with the relay device 200 , receive a river information DB through the relay device 200 , and manage the received river information DB. In addition, the integrated server 300 may provide partial information of the river facility DB to the relay device 200 according to the request of the relay device 200 .

The DB 400 may store a river information DB and a river facility DB. The DB 400 may be implemented as one physically coupled device, but is not necessarily limited thereto and may be implemented as a plurality of physically separated devices. For example, the DB 400 may be implemented to include a first DB for storing the river information DB and a second DB for storing the river facility DB.

Referring to FIG. 3 , a mobile device according to an embodiment of the present invention is a mobile device including a communication unit 111 , a GPS receiver 112 , a control unit 113 , a storage unit 114 , a power supply unit 115 , and a driving unit 116 . 110 , a lidar 121 , a hyperspectral sensor 122 , and a sensor unit 120 including an optical camera 123 .

The communication unit 111 may wirelessly interwork with the relay device 200 and transmit/receive various types of information.

The GPS receiver 112 may receive location information, that is, coordinate values from a GPS satellite.

Upon receiving a control command from the relay device 200 , the controller 113 may move to a predetermined location according to the received control command, and may control to measure and transmit the first river information and the second river information.

The storage unit 114 may store various types of information related to river investigation, for example, coordinate values and measurement values.

The power supply unit 115 may supply power to all electronic components mounted inside the moving body 110 . The power supply unit 115 may include, for example, a rechargeable battery.

The driving unit 116 may drive the moving object 110 to fly at a flight altitude, a flight path, and a flight speed. The driving unit 116 may include, for example, a DC (Direct Current) motor.

The lidar 121 is mounted on the movable body 110 and may measure the topography of the area to be investigated, that is, the distance from the topography around the river to the topography of the bottom of the river. The lidar 121 emits a laser signal and measures the distance from the flight altitude at which the moving object 110 is located to the river topography by using the laser signal reflected from the terrain and features.

The hyperspectral sensor 122 may be mounted on the movable body 110 and may acquire a hyperspectral image of an area to be irradiated. In general, the hyperspectral sensor 122 refers to equipment capable of acquiring all subdivided wavelength-specific images in a specific wavelength region, compared to conventional electro-optical/infrared imaging equipment that acquires a comprehensive image of visible light or a specific infrared region. . Although the hyperspectral sensor 122 has a slightly lower resolution, it is possible to photograph up to about 1,000 narrow spectral bands, so that the reflective characteristics of the object can be recorded as it is, and the terrain and features can be distinguished.

The optical camera 123 may be mounted on the movable body 110 and acquire an optical image of the area to be irradiated.

Referring to FIG. 4 , the relay device 200 according to an embodiment of the present invention includes a communication unit 211 , an input unit 212 , a control unit 213 , a storage unit 214 , a power supply unit 215 , and a display unit 216 . may include

The communication unit 211 may wirelessly interwork with the mobile device 100 and the integrated server 300 and transmit/receive various types of information. The communication unit 211 may be implemented to include a first communication unit and a second communication unit. The first communication unit may interwork with the mobile device 100 and the second communication unit may interwork with the integrated server 300 .

The input unit 212 may receive operation information according to a user's key or menu operation.

The controller 213 may build a river information DB and a river facility DB for the investigation target area based on the first and second river information measured from the mobile device 100 .

The storage unit 214 may store the first river information, the second river information, the river information DB, and the river facility DB.

The power supply unit 215 may supply power to all electronic components mounted in the relay device 200 . The power supply unit 215 may include, for example, a rechargeable battery.

The display unit 216 may display the first river information, the second river information, the river information DB, and the river facility DB.

5 is a first diagram illustrating a river topography measurement process according to an embodiment of the present invention, and FIG. 6 is a diagram for explaining the river topography measurement principle shown in FIG. 5 .

Referring to FIG. 5 , the mobile device according to an embodiment of the present invention drives the lidar 121 to transmit a first laser signal and a second laser signal having different wavelengths, and a first laser that is reflected back by terrain and features The first river information, that is, the eleventh river information and the twelfth river information, may be obtained by receiving the signal and the second laser signal and measuring the topography and the distance to the feature.

Referring to FIG. 6 , the mobile device uses a first laser signal S1 and a second laser signal S2 having different wavelengths, the first laser signal S1 being a Near Infrared (NIR) laser signal, The second laser signal S2 may be a green laser signal.

Since the first laser signal S1 does not penetrate the water surface but reflects it, the topography around the river can be measured by using the first laser signal S1. On the other hand, since the second laser signal S2 can penetrate the water surface, the topography of the river bed can be measured by using the second laser signal S2.

At this time, since the laser signal consists of one or more carrier wavelengths, the intensity is different for each carrier wavelength using the laser signal, and thus the elevation can be measured.

In this case, the mobile device may measure the irradiated metabolic region using the lidar 121 , and may circularly scan the irradiated metabolic region at predetermined positions using the lidar 121 .

Next, the mobile device may transmit the obtained first river information to the relay device.

Next, the relay device may calculate the two-dimensional planar river topography information for the investigation target area by using the transmitted first river information. That is, the relay device calculates the topography around the river of the investigation target area by using the eleventh river information among the transmitted first river information, and calculates the river bottom topography of the investigation target area by using the twelfth river information, Based on the topography and the topography of the river bed, two-dimensional planar topography of rivers can be calculated.

For example, the relay device may convert distance information, which is the first river information, into a point cloud, and calculate the two-dimensional planar river topography information using the converted point cloud.

In the embodiment of the present invention, lidar is used to acquire river topography information. In the case of lidar, a measuring device that uses the transmission and reflection characteristics of a laser signal. It has the characteristic of increasing uncertainty.

In order to compensate for the shortcomings of the measurement results using this lidar, we intend to use a hyperspectral sensor. Since the hyperspectral sensor measures the depth of water by analyzing the spectral characteristics of light reflection, uncertainty increases at high depths where light transmission is weak.

Therefore, we intend to match the river topography information using lidar, which has a characteristic of increasing uncertainty at low depth, and a hyperspectral sensor, which has a characteristic of increasing uncertainty at high depth.

7 is a second diagram illustrating a river topography measurement process according to an embodiment of the present invention, FIG. 8 is a diagram illustrating the river topography matching process shown in FIG. 7, and FIG. 9 is a river topography measurement principle shown in FIG. FIG. 10 is a view for explaining the river topography matching principle shown in FIG. 7 .

Referring to FIG. 7 , the mobile device according to the embodiment of the present invention drives the lidar 121 ( S710 ) to transmit a first laser signal and a second laser signal having different wavelengths, and is reflected by the terrain and features. The distance information may be obtained by receiving the first laser signal and the second laser signal and measuring the distance to the topography and the feature (S730).

As shown in FIG. 9 , the mobile device may acquire continuous 2D planar information by scanning the river section in a circle using the lidar 121 .

Next, the mobile device may transmit the obtained distance information to the relay device (S750), and the relay device may calculate the first river topography information using the transmitted first river information (S770).

Next, the mobile device may drive the hyperspectral sensor (S720) to obtain a hyperspectral image of the area to be irradiated (S740).

As illustrated in FIG. 9 , the mobile device may acquire continuous 2D planar information by scanning a river section in a line using a hyperspectral sensor.

Next, the mobile device transmits the acquired hyperspectral image to the relay device (S760), and the relay device may calculate the second stream topography information using the spectral characteristics of the transmitted hyperspectral image (S780).

Next, the relay device may match the first river topography information with the second river topography information (S790).

In this case, the matching process will be described in detail as follows. That is, referring to FIG. 8 , the relay device extracts a first river edge from the first river topography information (S791), and extracts a first matching criterion, for example, a specific curvature, an inflection point section, etc. from the extracted river edge. It can be (S793).

The relay device may extract a second river edge from the second river topography information (S792), and extract a second matching criterion, eg, a specific curvature, an inflection point section, and the like, from the extracted river edge (S794).

Next, the relay device matches the first river topography information and the second river topography information based on the first matching criterion and the second matching criterion, but uses the first river topographic information in the high depth region, and in the low water depth region The second stream topography information may be used and matched (S795).

To elaborate, as shown in FIG. 10, both the lidar and hyperspectral sensors are based on the fact that both the lidar and the hyperspectral sensor can accurately analyze the edge of the river where the water surface begins, that is, the part where water and the ground meet. can be defined as the edge of the river.

Therefore, if the first and second stream topographic information are combined with the river edge as a standard so that the first and second matching criteria coincide, the low-water depth section in which the error occurs in the first river topographic information is 2 is corrected with the river topography information, and the high-depth section in which an error occurs in the second river topography information is corrected with the first river topography information.

Referring to FIG. 11 , the mobile device according to an embodiment of the present invention may drive a hyperspectral sensor (S1110) to acquire a hyperspectral image (S1130), and transmit the acquired hyperspectral image to a relay device (S1150) .

Next, the mobile device may drive the optical camera (S1120) to acquire an optical image (S1140), and transmit the acquired optical image to the relay device (S1160).

Next, upon receiving the hyperspectral image and the optical image, the repeater may extract spectral characteristics from the hyperspectral image (S1170) and extract image characteristics from the optical image (S1180).

In this case, the relay device may extract the spectral characteristics of the river using each pixel value of the hyperspectral image, which is the 21st river information, measured according to the river width, and a predefined hyperspectral standard index.

Also, the relay device may match the optical image, which is the 22nd river information measured according to the river width, into a single image, and extract image characteristics of the river facility by using the river facility DB.

Accordingly, the relay device may calculate river characteristic information for the area to be investigated by using the spectral characteristics and image characteristics extracted in this way ( S1190 ). Here, the river characteristic information may include information such as water depth, water quality, and floating sand calculated by spectral characteristics and information such as water depth, flow velocity, and river facilities calculated by image characteristics.

In the embodiment, the case of using the river facility DB is described as an example, but it is not necessarily limited thereto, and the river facility may be recognized and converted into a DB using a sensor.

12 is a view showing a river facility recognition process according to an embodiment of the present invention, and FIG. 13 is a view for explaining the river facility recognition principle shown in FIG. 12 .

12, the mobile device according to an embodiment of the present invention drives an optical camera (S1210) to acquire an optical image of an area to be irradiated (S1211), and drives a lidar (S1220) to get to the topography and features Distance information is obtained by measuring the distance (S1221), and a hyperspectral sensor is driven (S1230) to obtain a hyperspectral image of the irradiation target area (S1231).

Next, the mobile device may transmit the acquired optical image, distance information, and hyperspectral image to the relay device (S1212, S1222, S1232).

Next, the relay device may recognize a river facility such as a beam, embankment, and shoreline in the investigation target area based on the optical image acquired through the optical camera (S1213).

Referring to FIG. 13 , the repeater may extract a boundary line for detecting an object, ie, a river facility, from the optical image (S1213-1), and emphasize the boundary line using a predetermined filter (S1213-2) .

The relay device extracts a feature point from the optical image in which the boundary line is emphasized using a pre-built image library (S1213-3), and recognizes the river facility using a database built in advance based on the extracted feature point, that is, the river facility DB. It can be done (S1213-4).

Next, the relay device recognizes the river facility in the investigation target area based on the distance information measured through the lidar (S1223), and the shape of the recognized river facility matches the shape of the recognized river facility based on the optical image It is possible to first verify the river facilities as a result of the comparison by comparing whether or not there is (S1214).

In this case, the relay device may convert distance information measured through the lidar into a point cloud and recognize the river facility using the converted point cloud.

In addition, when the shape of the river facility recognized based on the optical image matches the shape of the river facility recognized based on the optical image, the relay device may first verify as the river facility. Here, the shape matching means matching within a predetermined error range.

Next, the relay device may check the first verified constituent material of the river facility, for example, concrete, based on the hyperspectral image (S1233), and may perform secondary verification with the river facility based on the confirmed constituent material (S1215) .

In this case, the relay device may extract the spectral characteristics from the hyperspectral image to identify the constituent materials.

In addition, the relay device may compare whether the identified constituent materials match the pre-established constituent materials of the first verified river facility, and may perform secondary verification of the river facility as a result of the comparison.

Next, the relay device may update the river facility DB based on the received information on the river facility (S1216). In this case, the relay device may update the river facility DB if the provided information on the river facility exists in the river facility DB, or may add it if it does not exist.

Referring to FIG. 14 , when the mobile device according to an embodiment of the present invention receives a movement command instructing river survey, it may move to a location of a corresponding survey target area according to the received movement command ( S1410 ).

Next, the mobile device drives the lidar (S1420) to measure the terrain and the distance to the feature (S1330), and drives the optical camera (S1421) to obtain an optical image of the irradiation target area (S1331), hyperspectral By driving the sensor (S1422), it is possible to obtain a hyperspectral image of the area to be irradiated (S1432).

Next, the mobile device may provide distance information, an optical image, and a hyperspectral image to the relay device (S1440, S1441, and S1442).

Next, the relay device may calculate river topography information using the distance information ( S1450 ), and may calculate river characteristic information using the optical image and hyperspectral image ( S1451 ).

Next, the relay device analyzes the calculated river topography information and river characteristic information to build a river information DB for the area to be investigated (S1460), and selectively selects at least a part of the river topography information, river characteristic information, and river information DB (S1460) It can be provided to the integration server (S1470).

Referring to FIG. 15A , when a system is configured with a mobile device and an integrated server without operating a relay device, self-computational performance limitations of drones and mission equipment (lidar, hyperspectral sensor, optical camera), data capacity, and network Real-time transmission and reception are difficult due to speed limit and physical distance limit.

Referring to FIG. 15B , when a system is configured of a mobile device and an integrated server by operating a relay device, real-time transmission and reception between the mobile device and the relay device and between the relay device and the integrated server is possible, and the relay device has its own river information image Conversion and analysis, river information DB construction, digital twin module application, and river facility DB linkage necessary information transmission and reception are possible.

Referring to FIG. 16 , the mission scenario is a drone and mission equipment for the most efficient river investigation using a drone specialized for river investigation and mission equipment that can be mounted on the drone, that is, lidar, hyperspectral sensor, and optical camera. We can suggest the best way to operate.

The term '~ unit' used in this embodiment means software or hardware components such as field-programmable gate array (FPGA) or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. '~unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' refers to components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card.

Although the above has been described with reference to the preferred embodiment of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention as described in the claims below. You will understand that it can be done.

[Explanation of code]

100: mobile device

200: relay device

300: Integration Server

400: DB

Claims

a mobile device equipped with a lidar and hyperspectral sensor, acquiring distance information using the lidar while flying in a river area including jean and excluding regions, and acquiring a hyperspectral image using the hyperspectral sensor; and

While moving along the river region according to the flight of the mobile device, a relay device that receives the distance information and the hyperspectral image and calculates two-dimensional planar river topography information for the river region as a result of analysis,

The mobile device is

The distance information is obtained using a first laser signal and a second laser signal having different wavelengths of the lidar,

A river topography surveying system for obtaining distance information around a river using the first laser signal and obtaining distance information on a river bottom using the second laser signal.
According to claim 1,

The first laser signal is a near infrared (Near Infrared) laser signal,

wherein the second laser signal is a green laser signal.
According to claim 1,

The relay device is

Calculating first river topography information using the distance information,

Calculating second river topography information using the hyperspectral image,

and matching the calculated first river topography information with the second river topography information.
4. The method of claim 3,

The relay device is

extracting a first matching criterion from the first river topography information,

extracting a second matching criterion from the second river topography information,

and matching the first river topography information and the second river topography information so that the extracted first matching criteria and the second matching criteria coincide with each other.
5. The method of claim 4,

The relay device is

extracting a first river edge from the first river topography information, and extracting the first matching criterion from the extracted first river edge;

and extracting a second stream edge from the second stream topography information, and extracting the second matching criterion from the extracted second stream edge.
LiDAR, a mobile device equipped with a hyperspectral sensor acquiring distance information using the lidar while flying over a river region including the jean and excluding regions, and acquiring a hyperspectral image using the hyperspectral sensor; and

The relay device receives and analyzes the distance information and the hyperspectral image while moving along the river region according to the flight of the mobile device, and calculating two-dimensional planar river topography information for the river region. do,

In the acquiring step,

The distance information is obtained using a first laser signal and a second laser signal having different wavelengths of the lidar,

A river topography surveying method for obtaining distance information around a river using the first laser signal and obtaining distance information on a river bottom using the second laser signal.
7. The method of claim 6,

The first laser signal is a near infrared (Near Infrared) laser signal,

wherein the second laser signal is a green laser signal.
7. The method of claim 6,

In the calculating step,

Calculating first river topography information using the distance information,

Calculating second river topography information using the hyperspectral image,

and matching the calculated first river topography information with the second river topography information.
9. The method of claim 8,

In the calculating step,

extracting a first matching criterion from the first river topography information,

extracting a second matching criterion from the second river topography information,

and matching the first river topography information and the second river topography information so that the extracted first matching criteria and the second matching criteria coincide with each other.
10. The method of claim 9,

In the calculating step,

extracting a first river edge from the first river topography information, and extracting the first matching criterion from the extracted first river edge;

and extracting a second river edge from the second river topography information, and extracting the second matching criterion from the extracted second river edge.