JP6898396B2 - Underwater observation system - Google Patents

Description

The present invention relates to a water bottom observation system that acquires water bottom image information of the sea or lake, processes the image, and observes the water bottom.

Japanese Unexamined Patent Publication No. 2003-4845 (Patent Document 1) discloses an observation method using an echo sounder that supports the water surface so as to travel and move (see FIG. 1 of Patent Document 1). Although it is possible to obtain map information such as a wide range of seafloor topography by water depth observation, it is limited to water depth observation in extremely shallow areas, and it is not possible to observe deep water bottoms.

Further, Japanese Patent No. 4173027 (Patent Document 2) discloses an observation method using a video camera that is towed and supported in water (see FIG. 1 of Patent Document 2). It is possible to observe images over a wide area.

Japanese Unexamined Patent Publication No. 2003-4845 Japanese Patent No. 4173027

Here, the underwater image obtained by the video camera can grasp the optical properties by dynamic observation in the water, but since it is transient image information and does not have geographic coordinates, it relates to the aspect of the water bottom. There was a problem that it could not be the basis of quantitative analysis covering all optical properties.

Further, in Patent Document 2, since the water bottom image is captured by a video camera, the water bottom region is imaged in the shadow of the sun's rays or at dawn / twilight, or the water depth is deep and the sun's rays do not reach. The problem is that it is not possible to accurately create bottom surface data when imaging the bottom region, when imaging the bottom region where the water quality is polluted, or when the bottom region to be imaged is in the shade. was there.

Therefore, the present invention images the bottom region where the water quality is polluted when the bottom region is imaged in the shade of the sun's rays or at dawn / twilight, or when the bottom region is deep and the sun rays do not reach. In this case, it is an object of the present invention to provide a water bottom observation system capable of accurately creating water bottom surface data together with geographic coordinate positions even when the water bottom area to be imaged is shaded.

An object of the present invention is
A submersible that can move underwater and
A plurality of underwater cameras mounted on the submersible that continuously detect visible light,
A laser ranging device that emits a laser beam, receives a laser beam reflected by the seafloor, and can continuously measure the distance to the seafloor in synchronization with the plurality of underwater cameras.
A posture sensor that detects the postures of the plurality of underwater cameras and the laser ranging device, and
A GNSS sensor that detects the imaging position of the plurality of underwater cameras and the measurement position of the laser ranging device, and
Synchronized recording of captured image data captured by the plurality of underwater cameras, attitude data of the plurality of underwater cameras detected by the attitude sensor, and imaging position data of the plurality of underwater cameras detected by the GNSS sensor. Recording means and
An image processing means for processing the recorded image of the recording means is provided.
The image processing means obtains water depth data in which geographic coordinates are assigned by image processing based on the respective posture data and shooting position data for an overlapping range of a plurality of shot images taken by the underwater camera, and the laser ranging device. DSM data can be created by complementing using complementary data created based on the distance data indicating the distance to the bottom of the water measured by and the attitude data of the laser ranging device detected by the attitude sensor. Consists of
The laser ranging device includes a diffusing member that diffuses a laser beam, divides the laser beam into n × n laser beams, and irradiates an n × n matrix-like region on the sea surface , and further emits a laser beam. storage means for storing the release time and intensity, and a photo sensor for detecting the detection time of the laser beam reflected by said matrix area of the seafloor, the laser beam reflected by said matrix area of the seafloor The area sensor for detecting the detection intensity of the laser beam is provided, and the emission time and emission intensity of the laser beam stored in the storage means, the detection time of the laser beam detected by the photosensor, and the area. A water bottom observation system characterized by having a light receiving sensor configured to calculate the distance to the matrix-like region of the sea surface based on the detection intensity with the laser beam detected by the sensor. Achieved by.

In the present specification, DSM is an abbreviation for Digital Surface Model and refers to a digital surface model.

According to the present invention, in the water bottom observation system, since a plurality of underwater cameras for detecting visible light are mounted on the submersible, images of the water bottom are taken by the plurality of underwater cameras to visually check the condition of the water bottom. It can be shown in an easy-to-understand manner.

Further, according to the present invention, since the water bottom observation system is provided with a laser ranging device capable of measuring the distance to the water bottom in addition to a plurality of underwater cameras that detect visible light, the water depth is deep. Due to the lack of sunlight and insufficient brightness, it is not possible to accurately create underwater surface data with multiple underwater cameras that detect visible light, and the underwater surface data obtained by multiple underwater cameras. Due to the lack of a part of the water or the pollution of the water quality, it is not possible to accurately create the bottom surface data with multiple underwater cameras that detect visible light, and multiple underwater cameras. If a part of the bottom surface data obtained by is missing, it will be shaded when shooting the bottom with multiple underwater cameras that detect visible light, and it is possible to create the bottom surface data accurately. If this is not possible and some of the underwater surface data obtained by multiple underwater cameras is missing, then the sun's rays are shaded, dawn / twilight, or the contrast is extremely high, which is sufficient for lack of brightness. When there is a part where exposure cannot be obtained and a part of the water bottom surface data obtained by multiple underwater cameras is missing, the combination processing (image matching processing) of the water bottom surface images obtained by multiple underwater cameras can be performed well. Even if part of the bottom surface data is missing, the distance to the water depth is measured by a laser ranging device, and the loss of the bottom surface data obtained by multiple underwater cameras that detect visible light is complemented. It becomes possible to do.

In a preferred embodiment of the present invention, the laser ranging device includes a diffusing member that diffuses a laser beam and irradiates the seabed in an n × n matrix.

In a preferred embodiment of the present invention, the underwater camera is a video camera capable of shutter control, and the plurality of video cameras are arranged on the left and right sides.

According to this preferred embodiment of the present invention, since the video cameras are arranged on the left and right sides, it is possible to secure an overlapping range of 80% for the bottom image and efficiently shoot the images, and the shutter control allows waves. Even if there is a sudden change in the viewpoint due to the above, a clear bottom image can be taken, so that the image processing accuracy can be improved.

In a preferred embodiment of the present invention, the posture sensor and the GNSS sensor are configured by a GNSS / gyro device.

According to the present invention, when the bottom area is imaged in the shade of the sun's rays or at dawn / twilight, or when the bottom area is deep and the sun rays do not reach, the bottom area where the water quality is polluted is imaged. In this case, it is possible to provide a water bottom observation system that can accurately create water bottom surface data together with geographic coordinate positions even when the water bottom area to be imaged is shaded.

FIG. 1 is a functional configuration diagram of a water bottom observation system according to a preferred embodiment of the present invention. FIG. 2 is a block diagram showing the components of the bottom observation system according to the preferred embodiment of the present invention shown in FIG. FIG. 3 is a schematic perspective view of the laser beam emitting portion of the laser ranging device. FIG. 4 is a schematic perspective view of a laser beam receiving unit of the laser ranging device. FIG. 5 is a substantially vertical cross-sectional view of the light receiving sensor. FIG. 6 is a block diagram of a control system and a detection system of the laser ranging device. FIG. 7 is a flowchart showing a process of observing the bottom of the water by the bottom observation system according to the preferred embodiment of the present invention shown in FIGS. 1 to 6.

FIG. 1 is a functional configuration diagram of the water bottom observation system according to the preferred embodiment of the present invention, and FIG. 2 is a block diagram showing components of the water bottom observation system according to the preferred embodiment of the present invention shown in FIG. Is.

As shown in FIGS. 1 and 2, the bottom observation system 1 according to the preferred embodiment of the present invention includes a submersible 2 that can move underwater and a pair of underwater video cameras 3 and 3 mounted on the submersible 2. (In FIG. 1, only one is shown), the laser ranging device 4 mounted on the submersible 2, the imaging positions of the pair of underwater video cameras 3 and 3, and the ranging of the laser ranging device 4. Photographed by a pair of underwater video cameras 3 and 3 and a GNSS / gyro device 5 that detects the position and detects the posture during shooting of the pair of underwater video cameras 3 and 3 and the posture during distance measurement of the laser ranging device 4. Synchronized the data of the bottom image, the shooting position data of the pair of underwater video cameras 3 and 3 when the bottom image detected by the GNSS / gyro device 5 was taken, and the attitude data of the pair of underwater video cameras 3 and 3. Based on the video recorders 7 and 7 recorded in the video recorder 7 and 7 and the bottom image data, shooting position data and attitude data recorded in the video recorders 7 and 7, the bottom image is processed in real time on the submersible boat 2 or the bottom image is processed. A personal computer 9 provided with an image processing unit 8 that processes an image of the bottom of the water after the shooting work is completed is provided.

As each video camera 3, a video camera capable of underwater photography, which is housed in a housing and has an electronically controllable high-speed shutter, is used. As the video camera 3, 80% of the underwater image can be superposed on each other, and a clear image can be recorded by a high-speed shutter even when it is shaken by waves.

Although only one is shown in FIG. 1, the pair of underwater video cameras 3 and 3 are arranged on the left and right sides of the submersible 2.

The GNSS / gyro device 5 is configured to detect the three-dimensional imaging position of the pair of underwater video cameras 3 and 3 and the three-dimensional ranging position of the laser ranging device 4 so that high-precision DGNSS can be applied. The GNSS / gyro device 5 further provides the attitude data in the optical axis direction of the pair of underwater video cameras 3 and 3 and the attitude of the laser ranging device 4 at the time of ranging, that is, the laser beam from the laser ranging device 4. It is configured to detect the emission direction.

The video recorders 7 and 7 include the bottom image taken by each video camera 3 and 3, the shooting position data of each video camera 3 and 3 detected by the GNSS / gyro device 5, and the attitude data of each video camera 3 and 3. Are synchronizedly recorded on a recording medium, and this is input to the image processing unit 8 of the personal computer 9 mounted on the submarine 2. Alternatively, the underwater image taken by each video camera 3 or 3 and the shooting position data of each video camera 3 or 3 detected by the GNSS / gyro device 5 and the attitude data of each video camera 3 or 3 are recorded in synchronization with each other. It is also possible to configure the portable media or these data to be input to an image processing unit (not shown) of a personal computer (not shown) located on the ground by wireless transmission.

The image processing unit 8 contains video data on the bottom of the water generated by the pair of video cameras 3 and 3, posture data of the pair of video cameras 3 and 3 detected by the GNSS / gyro device 5, and a pair of video cameras 3 and 3. The three-dimensional position data of the above is input, and the image processing unit 8 of the personal computer creates DSM data which is a numerical ground surface model expressed on geographic coordinates by stereo matching based on these data. It is configured.

As shown in FIG. 2, the water bottom observation system 1 further includes video editing machines 12 and 12, a synchronization signal generator 14 that generates a synchronization signal, a DSM data generation unit 15 that generates DSM data, and DSM data. The orthophotograph generation unit 16 for generating an orthophotograph is provided based on the above.

FIG. 3 is a schematic perspective view of the laser beam emitting portion of the laser ranging device 4.

As shown in FIG. 3, the laser ranging device 4 includes an LED laser light source 21 that emits a laser beam 20 in a pulse shape, and the laser beam 20 emitted from the LED laser light source 21 is incident on the collimator lens 22. Is converted into a parallel beam. The laser beam 20 converted into a parallel beam by the collimator lens 22 is incident on the diffusing member 23, and the laser beam 20 is divided into a large number of laser beams 25 by the diffusing member 23 to form an n × n matrix. For example, the bottom of the sea is irradiated in a matrix of 128 × 128.

As the diffusion member 23, for example, the diffusion member used in "3D Flash Lidar" (registered trademark) manufactured and sold by Advanced Scientific Concepts, Inc. is preferably used.

FIG. 4 is a schematic perspective view of the laser beam receiving unit of the laser ranging device 4.

As shown in FIG. 4, the laser beam 45 divided by the diffusing member 23 and reflected by the seabed is condensed by the condenser lens 26 and photoelectrically detected by the light receiving sensor 27.

FIG. 5 is a schematic vertical sectional view of the light receiving sensor 27, and as shown in FIG. 5, the laser beam 20 emitted from the LED laser light source 21 detects the laser beam 45 generated by being reflected by the sea surface. It includes a photo sensor 28 that detects the detection time up to, and a CCD sensor 29 that detects the intensity of the laser beam 45 reflected by the bottom of the sea.

FIG. 6 is a block diagram of the control system and the detection system of the laser ranging device 4.

As shown in FIG. 6, in the laser ranging device 4, the time when the laser beam 20 is emitted from the laser light source 21 in a pulsed manner and the laser beam 45 generated by the laser beam 20 being reflected by the sea surface are set. A first memory area 30A that stores the time received by the photo sensor 28, and a second memory that stores the intensity of the laser beam 20 emitted from the laser light source 21 and the intensity of the laser beam 45 detected by the CCD sensor 29. It has a RAM 30 having an area 30B.

Further, in the laser ranging device 4, the photosensor 28 receives the time when the laser beam 20 is emitted from the laser light source 21 stored in the first memory area 30A of the RAM 30 and the laser beam 45 reflected by the sea surface. The controller 31 calculates the distance to the sea surface based on the time, the intensity of the laser beam 20 emitted from the laser light source 21, and the intensity of the laser beam 45 detected by the CCD sensor 29.

Further, as shown in FIG. 6, the laser ranging device 4 includes a laser data processing unit 10 that processes data obtained by irradiation of the laser beam 20.

When the laser beam 20 is divided by the diffusion member 23 and irradiates the sea surface in an n × n matrix, the laser beam 25 reflected by the n × n matrix elements is used as the photo sensor 28 and the CCD sensor. By photoelectric detection by 29, the distance between the element and the laser light source 21 can be accurately calculated, and therefore, the distance between all the elements of the n × n matrix and the laser light source 21 can be accurately calculated. Becomes possible.

FIG. 7 is a flowchart showing a process of observing the seabed by the water bottom observation system 1 according to the preferred embodiment of the present invention shown in FIGS. 1 to 6.

When the start signal is input to the personal computer 9 by the operator, the drive signal is output from the personal computer 9 to the synchronization signal generator 14, and the synchronization signal generator 14 causes the pair of video cameras 3 and 3 and laser measurement. A synchronization signal is output to the distance device 4, the GNSS / gyro device 5, and the conversion software 35. At this time, the personal computer 9 stores the time when the laser beam 20 is emitted from the laser light source 21 in the first memory area 30A in the RAM 30 of the laser ranging device 4, and the laser beam emitted from the laser light source 21. The intensity of 20 is stored in the second memory area 30B in the RAM 30 of the laser ranging device 7.

Upon receiving the synchronization signal, the pair of video cameras 3 and 3 start shooting, and color images of the shooting areas 32 and 32 on the seabed are shot.

On the other hand, the laser ranging device 4 emits the laser beam 20 in a pulse shape from the laser light source 21, converts it into a parallel beam by the collimator lens 22, and then causes the laser beam 20 to enter the diffusion member 23. By passing through the diffuser 23, the laser beam 20 is divided into a large number of laser beams 25 and n × n laser beams 25, for example, 128 × 128 laser beams 25, and the pair of video cameras 3 and 3 The overlapping imaging regions 33 where the imaging regions 32 and 32 on the sea surface overlap are irradiated, and an n × n matrix-like irradiation portion 33A is formed in the overlapping imaging regions 33.

The laser beam 45 reflected by each of the n × n matrix-like irradiation units 33A on the seabed is focused by the condenser lens 26 and is photoelectrically detected by the light receiving sensor 27.

As described above, the light receiving sensor 27 is composed of a photo sensor 28 that detects the detection time of the laser beam 25 reflected by the sea floor and a CCD sensor 29 that detects the intensity of the laser beam 25 reflected by the sea floor. ing.

When the photosensor 28 detects the laser beam 45 reflected by each of the n × n matrix-like irradiation units 33A on the seabed, the time during which the laser beam 45 is detected is set in the first memory area 30A in the RAM 30. Store in. Here, the inside of the first memory area 30A is divided into n × n matrix-like memory areas corresponding to the n × n matrix-like irradiation unit 33A, and the photosensor 28 is n × n on the seabed. The detection time of the laser beam 45 reflected by each of the matrix-shaped irradiation units 33A of the above is stored in the corresponding matrix-shaped memory area in the first memory area 30A.

On the other hand, the CCD sensor 29 detects the intensity of the laser beam 45 reflected by each of the n × n matrix-like irradiation units 33A on the seabed, and is reflected by each of the n × n matrix-like irradiation units 33A on the seabed. The intensity of the laser beam 45 is stored in the corresponding matrix-like memory area in the second memory area 30B.

Next, the controller 31 accesses the RAM 30, and the time when the laser beam 20 is emitted from the laser light source 21 stored in each of the matrix-shaped memory areas in the first memory area 30A and the time when the laser beam 20 is emitted by the photosensor 28 and the laser beam 45 are generated by the photosensor 28. The detected time and the intensity of the laser beam 20 emitted from the laser light source 42 stored in each of the matrix-shaped memory areas in the second memory area 30B and the intensity of the laser beam 45 detected by the CCD sensor 29. Based on this, the water depth data of each of the n × n matrix-like irradiation unit 33A on the sea surface is calculated.

In response to the synchronization signal, the GNSS / gyro device 5 generates posture data and position data of the pair of video cameras 3 and 3, activates the conversion software 35, and converts the converted posture data and the converted position data. Let me calculate.

In response to the synchronization signal, the image data corresponding to the image of the seabed taken by the pair of video cameras 3 and 3 is output to the video recorders 7 and 7, and further, the serial number images are output by the video editing machines 12 and 12. Is generated. Next, the focal length and lens distortion are separately corrected using the observed camera parameters, and the corrected left and right serial number images (pair images every 1/30 second) are generated.

Here, the camera parameters are observed by taking a picture of a target separately installed in the water tank with the underwater video camera 3 and obtaining the focal length and lens distortion using a photogrammetric formula.

Next, for example, template matching is executed on the corrected left and right serial number images to calculate the lateral parallax.

The lateral perspective calculated in this way, the converted position data and the converted attitude data of the pair of video cameras 3 and 3 in which the position data and the attitude data measured by the GNSS / gyro device 5 are converted by the conversion software 35, and the lens. The altitude value is calculated using the focal length of, and the first water depth data is calculated.

Next, among the corrected left and right serial number images, the corrected position data and the corrected posture data of the video cameras 3 and 3 are used for the corrected serial number image (N-1) having a time difference between the left image and the right image. Then, geometric correction is performed on the same coordinates as the corrected serial number image N, and the geometrically corrected serial number image (N-1) is created.

For example, template matching is executed on the geometrically corrected serial number image (N-1) and the corrected serial number image N thus obtained, and the vertical parallax is calculated.

Next, the longitudinal focal length calculated in this way and the converted position data and converted posture data of the pair of video cameras 3 and 3 in which the position data and the posture data measured by the GNSS / gyro device 5 are converted by the conversion software 35. , The focal length of the lens is used to calculate the altitude value, and the second water depth data is calculated.

On the other hand, the third water depth data is calculated using the distance data generated by the laser distance measuring device 4, the position data and the attitude data of the laser distance device 4, and the focal length of the lens.

When the first water depth data, the second water depth data, and the third water depth data are calculated in this way, the DSM data creation unit 15 creates the DSM data.

That is, the first water depth data and the second water depth data calculated based on the image data taken by the pair of underwater video cameras 3 and 3 are mainly used, and the complementary data is generated by the laser ranging device 4. DSM data is created by interpolation / extrapolation calculation using the third water depth data calculated based on the distance data.

The DSM data created by the DSM data creation unit 15 is an orthographic image creation software 40 that uses the lens distortion-corrected serial number image to shoot the lens distortion-corrected serial number image using the focal length of the lens, the converted position data, and the converted posture data. It is projected and an orthophoto in water is created.

Here, the third water depth data generated by the laser ranging device 4 is, for example, the water depth data of the n × n matrix-shaped region 33A, and the overlapping imaging region 33 is further divided into 2n × 2n. Even if the matrix-shaped regions 33A are generated and the water depth data of each region is obtained, the size of each region 33A is much larger than the pixels of the images taken by the pair of underwater video cameras 3 and 3, so that the pair The accuracy is lower than the measurement accuracy based on the images taken by the video cameras 3 and 3, and therefore, in this embodiment, the third water depth of the matrix-like region 33A generated by the laser ranging device 4. Based on the data, it is configured to generate complementary data for complementing the first water depth data and the second water depth data generated by the images taken by the pair of underwater video cameras 3 and 3.

In this way, the first water depth data and the second water depth data generated based on the images captured by the pair of underwater video cameras 3 and 3 and the complementary data generated by the laser ranging device 4 are used as the imaging target. DSM data for the seafloor region is generated. In this embodiment, the underwater video cameras 3 and 3 can visually observe the bottom region even in the deep sea region. However, in a deep sea region where the water depth is extremely deep, it is often difficult for the pair of underwater video cameras 3 and 3 to generate a clear bottom image because the sun's rays do not reach it. In addition, since the laser ranging device 4 generates complementary data, even in a deep sea region where it is difficult to generate a clear bottom image with a pair of underwater video cameras 3 and 3, even in a deep sea region where the water depth is extremely deep. It is possible to determine the depth of the bottom of the water, measure the bottom area, and observe the bottom of the water as desired.

Here, the complementary data generated by the laser ranging device 4 is not applied to the seafloor region where the DSM data correctly generated from the images taken by the pair of underwater video cameras 3 and 3 is present.

On the other hand, the corrected serial number image is superimposed and projected on the DSM data.

Next, the orthographic projection photograph creation unit 16 activates the orthographic image creation software 40, and uses the converted position data and the converted posture data generated by the conversion software 40 to obtain the image obtained in this way. Orthographic projection is performed and orthographic projection photographic image data is created.

In the observation, while moving the submarine 2 along the observation plan line, the water bottom image is taken by the pair of underwater video cameras 3 and 3 as described above, and the distance to the water bottom is measured by the laser ranging device 4. At the same time, the GNSS / gyro device 5 detects the viewpoint position and the optical axis direction, which are the shooting conditions of the pair of underwater video cameras 3 and 3, and the video recorders 7 and 7 synchronously record both of them.

After the observation is completed, the orthographic projection photographic image data is input to the image processing unit 8 of the personal computer 9 mounted on the submarine 2, or is a personal computer located on the ground by portable media or wireless transmission (Fig. It is input to the image processing unit (not shown) of (not shown), and the orthogonal projection image processing is executed.

This image processing output can visually show the situation of coral reefs and shallow waters in shallow waters in an easy-to-understand manner by visually representing the coral reefs and shallow waters in shallow waters in shallow water. Therefore, according to this embodiment, the underwater environment of coral reefs and shallow waters in shallow waters can be grasped in color, so that the growth status of coral reefs and shallow water vegetation (algae) due to different colors can be grasped. Is possible.

Further, according to the present embodiment, the water bottom observation system 1 includes a pair of underwater video cameras 3 and 3 for detecting visible light, and a laser ranging device 4 capable of measuring the distance to the water bottom. Because the water depth is deep, the sun's rays do not reach and the brightness is insufficient, so some underwater video cameras 3 and 3 that detect visible light cannot accurately create water bottom surface data, and underwater. Underwater video cameras 3 and 3 that detect visible light due to a lack of part of the water bottom surface data obtained by the video cameras 3 and 3 or because the water quality is polluted may be accurate and accurate. When data cannot be created and some of the bottom surface data obtained by the underwater video cameras 3 and 3 is missing, when the water bottom is photographed by the underwater video cameras 3 and 3 that detect visible light, If the bottom surface data cannot be created accurately due to shadowing and part of the bottom surface data obtained by the underwater video cameras 3 and 3 is missing, the sun's rays will be shaded or dawn / twilight. Occasionally, or when the contrast is so high that there are areas where the brightness is insufficient and sufficient exposure cannot be obtained, and some of the water bottom surface data obtained by the underwater video cameras 3 and 3 is missing. Laser measurement even when a part of the bottom surface data is missing due to poor combination processing (image matching processing) of the bottom surface images obtained by the pair of underwater video cameras 3 and 3 arranged on the left and right. The distance device 4 measures the distance to the water depth, and it becomes possible to supplement the loss of the water bottom surface data obtained by the underwater video cameras 3 and 3 that detect the visible light.

Further, according to the present embodiment, since the pair of underwater video cameras 3, 3 and the laser ranging device 4 and the GNSS / gyro device 5 are mounted on the submersible 2, even in a deep sea bottom region where the water depth is extremely deep. , A pair of video cameras 3 and 3 can generate an underwater image, thus making it possible to visually observe the underwater region.

In addition, in the deep sea where the water depth is extremely deep, the sun's rays do not reach and the brightness is insufficient, so it may be difficult for a pair of underwater video cameras 3 and 3 to generate a clear bottom image. However, according to the present embodiment, since the laser ranging device 4 generates complementary DSM data, it is difficult for the pair of underwater video cameras 3 and 3 to generate a clear water bottom image. Even in the deep sea region, it is possible to obtain the depth of the water bottom, measure the water bottom region, and observe the water bottom as desired.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

For example, in the above embodiment, a pair of underwater video cameras is provided, but the number of underwater video cameras may be a plurality and is not limited to two.

Further, in the above embodiment, the laser ranging device 4 for measuring the distance to the bottom of the water is manufactured and sold by a diffusion member 23, preferably Advanced Scientific Concepts, Inc., which divides the laser beam 20 into a large number of laser beams 25. Although it is equipped with the diffusing member used in the "3D Flash Lidar" (registered trademark), it is not always necessary to use the laser ranging device 4 provided with this type of diffusing member 23, and it is a fiber type. A laser ranging device or a scanning type laser ranging device can also be used.

Further, in the above embodiment, the seabed is observed, but the present invention is not limited to the observation of the seabed, and can be widely used for the observation of the water bottom such as lakes and marshes.

1 Underwater observation system 2 Submersible boat 3 Underwater video camera 4 Laser ranging device 5 GNSS / gyro device 7 Video recorder 8 Image processing unit 9 Personal computer 10 Laser data processing unit 11 DSM creation unit 12 Video editing machine 14 Synchronous signal generator 15 DSM creation unit 16 Orthophotograph creation unit 18 Orthogonal projection image data processing unit 20 Laser beam 21 LED laser light source 22 Collimeter lens 23 Diffusing member 25 Laser beam
26 Condensing lens 27 Light receiving sensor 28 Photo sensor 29 CCD sensor 30 RAM
30A First memory area 30B Second memory area 31 Controller 32 Shooting area of a pair of video cameras 33 Overlapping shooting area 33A Matrix-shaped area 35 Conversion software 40 Ortho image creation software 45 Laser beam

Claims (3)

A submersible that can move underwater and
A plurality of underwater cameras mounted on the submersible that continuously detect visible light,
A laser ranging device that emits a laser beam, receives a laser beam reflected by the seafloor, and can continuously measure the distance to the seafloor in synchronization with the plurality of underwater cameras.
A posture sensor that detects the postures of the plurality of underwater cameras and the laser ranging device, and
A GNSS sensor that detects the imaging position of the plurality of underwater cameras and the measurement position of the laser ranging device, and
Synchronized recording of captured image data captured by the plurality of underwater cameras, attitude data of the plurality of underwater cameras detected by the attitude sensor, and imaging position data of the plurality of underwater cameras detected by the GNSS sensor. Recording means and
An image processing means for processing the recorded image of the recording means is provided.
The image processing means obtains water depth data in which geographic coordinates are assigned by image processing based on the respective posture data and shooting position data for an overlapping range of a plurality of shot images taken by the underwater camera, and the laser ranging device. DSM data can be created by complementing using complementary data created based on the distance data indicating the distance to the bottom of the water measured by and the attitude data of the laser ranging device detected by the attitude sensor. Consists of
The laser ranging device includes a diffusing member that diffuses a laser beam, divides the laser beam into n × n laser beams, and irradiates an n × n matrix-like region on the sea surface , and further emits a laser beam. storage means for storing the release time and intensity, and a photo sensor for detecting the detection time of the laser beam reflected by said matrix area of the seafloor, the laser beam reflected by said matrix area of the seafloor The area sensor for detecting the detection intensity of the laser beam is provided, and the emission time and emission intensity of the laser beam stored in the storage means, the detection time of the laser beam detected by the photosensor, and the area. A water bottom observation system characterized by having a light receiving sensor configured to calculate the distance to the matrix-like region of the sea surface based on the detection intensity with the laser beam detected by the sensor. .. The water bottom observation system according to claim 1, wherein the plurality of underwater cameras are composed of video cameras capable of shutter control, and the plurality of video cameras are arranged on the left and right sides. The water bottom observation system according to any one of claims 1 or 2, wherein the posture sensor and the GNSS sensor are configured by a GNSS / gyro device.

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