JPH10325871A - Narrow multi-beam depth measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly precisely capture sea bottom information, by correcting a depth measuring position and water depth by a depth measuring sonar on the basis of a ship position, a ship main azimuth, an inclination angle, ship rolling and pitching, a sonic velocity and a sea level. SOLUTION: A real time kinematic(RTK) GPS position measuring device 3 highly precisely measures a ship position from a direction and a distance of a ground base station measured by a radio wave from an artificial satellite, and a ship azimuth is mesured by an azimuth compass 5. A multi-beam depth measuring sonar 6 measures water depth in width of double the water depth by 60 pieces of sound wave transmitters and receivers disposed in fan-shape, a chip motion correction device 8 measures heaving, pitching and rolling, and a sonic velocity sensor 9 measures sonic velocity at arbitrary water depth respectively. In addition, with regard to an inclination sensor, the inclination sensor measuring an inclination angle is arranged on two axes, and the inclination of the transmitter and receiver of a multi-beam depth sonar 6 is mesured. Measured data of each measuring device in which a data recorded file 2 is recorded are processed by a recording data processor 15, a depth measuring position and water depth are corrected and a water depth map, a contour map and the like are prepared and inputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a narrow multi-beam bathymetry system for surveying the seabed topography, managing the work in harbor construction, maintaining and managing port structures and facilities, and monitoring coastal deformation.

[0002]

2. Description of the Related Art FIG. 10 is a view for explaining a conventional example of a narrow multi-beam bathymetry system, where 31 is a data recording device, 32 is a data recording file, and 33 is a GPS.
A positioning device, 34 is an azimuth compass, 35 is a multi-beam sounding sonar, 36 is a hull motion compensation device, 37 is a sound speed sensor, and 38 is a data processing device.

[0003] Usually, an acoustic sounding instrument uses one acoustic beam to measure the water depth directly below a survey ship. However, a narrow multibeam bathymetry system is integrated with and fixed to the survey ship. 60 directivity from right below the ship in both left and right directions (90 ° surveying width) from sounding sonar
This is to measure the water depth by launching one acoustic beam at a time. For this reason, the narrow multibeam bathymetry system enables the acquisition of “area” depth data from “linear” depth data obtained by an acoustic depth sounder using a single acoustic beam, and enables precise seafloor topography And the shape of the structure can be accurately grasped. An example of the configuration is shown in FIG.
It is.

In the narrow multi-beam bathymetry system, a survey ship fixed by incorporating a multi-beam sonar 35 of a cross fan beam type is provided with a bow direction in order to correct the bathymetry position and the water depth as shown in FIG. Hull sway correction device 36 for measuring the pitching of the ship, rolling in the lateral direction with respect to the bow (heaving), and vertical fluctuation (heaving) received by the ship, GPS positioning device 33 for measuring the ship's position, and azimuth measurement Directional compass 34, sound velocity sensor 37 for measuring sound wave propagation velocity in water
The data recording device 31 records the measured data of water depth, ship position, heading azimuth, heaving, pitching, rolling, and sound velocity, and stores them in the data recording file 32. Then, these recorded measurement data are processed by the data processing device 38 to correct the sounding position and the water depth, and to perform a water depth map, an equal depth view, a sectional view,
It outputs a bird's-eye view, soil volume calculation results, and the like. The multibeam sounding sonar 35 has a transmitter / receiver having a transmission beam angle of 1.5 ° and 60 beams, and can measure a water depth twice as large as the water depth at a time. In addition, the beam width is as sharp as 1.5 ° x 1.5 °, which enables high-density recording as compared with conventional sounding data. Can be captured with precision.

[0005]

The depth of the water is determined by measuring the time required for the sound wave transmitted from the transducer in the multi-beam sounding sonar 35 to be reflected from the seabed, and multiplying this by the underwater speed of the sound wave. Therefore, the direction of the transducer, the sway of the hull, and the direction of the bow greatly affect the accuracy of the water depth. However, since the hull motion compensator and the compass do not measure the attitude of the transducer itself, but measure the attitude of the hull, the multi-beam sounding sonar 35 is integrated and fixed to a dedicated vessel. However, if the ship is chartered and outfitted for each field, the inclination of the transducer from the hull differs from field to field, and may change during the investigation in some cases.

When the multibeam sounding sonar 35 is fitted to a ship, the hull sways and the balance of the ship changes depending on the arrangement of people and objects on the ship. It is difficult to rig the hull for the purpose. Furthermore, it is difficult to prevent the inclination angle between the transducer and the hull from changing due to loose fittings or contact with obstacles during the investigation. Therefore, there is a problem that the measurement target position of the transducer becomes uncertain and a large error is caused in the obtained seafloor topographic information.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is to obtain highly reliable water depth information and topographic information by using a multi-beam sounding sonar mounted on a ship.

For this purpose, the present invention provides a multi-beam sounding sonar equipped with a plurality of sound wave transmitters and receivers arranged in a fan shape for measuring water depth and a transmitter and receiver integrated with the multi-beam sounding sonar. A vessel comprising a tilt angle measuring means for measuring a tilt angle of the transducer with respect to the vessel, a vessel position measuring means for measuring a vessel position, a bearing means for measuring an azimuth angle of a bow, pitching, rolling, and heaving. Ship sway measurement means for measuring the sway of, sound speed measurement means for measuring the sound speed according to the water depth, and measurement data recording means for recording the respective measurement data, the ship position,
Correcting the sounding position by the multi-beam sounding sonar based on the azimuth, inclination, pitching and rolling of the bow, and correcting the water depth by the multi-beam sounding sonar based on the sound velocity, heaving and tide level. Is what you do.

The tilt angle measuring means has means for displaying tilt angle data, makes it possible to display low-pass filtered tilt angle data, and includes a two-axis pipe in a pipe to which the transducer is attached. A tilt sensor is incorporated to measure the tilt angle between the transducer and the ship, and the tide level is a measured value or a predicted tide level at a tide station.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an embodiment of a narrow multi-beam bathymetry system according to the present invention.
FIG. 3 is a view showing a state in which a multi-beam sounding sonar of the narrow multi-beam bathymetry system according to the present invention is fitted to a small vessel or the like, and FIG. 3 is a view for explaining a processing flow of a recorded data processing device. In the figure, 1 is a data recording device, 2 is a data recording file, 3 is an RTKGPS positioning device, 4 is a positioning data recording and display device, 5 is an azimuth compass, 6 is a multi-beam sounding sonar, 7 is a sounding data recording and display device, 8
Denotes a ship sway correction device, 9 denotes a sound speed sensor, 10 denotes a tilt sensor, 11 denotes a tilt angle monitor, 15 denotes a recorded data processing device, 21 denotes a ship, and 22 denotes a pipe.

In FIG. 1, a data recording device 1 records measurement data of water depth, ship position, heading azimuth, heaving, pitching, rolling, sound velocity, and inclination angle, and stores the recorded data. This is the data recording file 2. The RTKGPS (real-time kinematic GPS) positioning device 3 measures the direction and distance from a ground reference station using radio waves from artificial satellites, and measures the position in real time with an accuracy of several cm. The positioning accuracy of 3 is “2cm +
1 ppm x distance from reference station ". The positioning data recording and display device 4 displays and records the ship position measured by the RTKGPS positioning device 3. Azimuth compass 5
Measures the azimuth of the bow in real time. The multi-beam sounding sonar 6, as shown in FIG. 2, is equipped with a pipe 22 of a boat 21 such as a small boat, and is equipped with 60 sound wave transducers at 1.5 ° (transmission beam angle of 1.5 °). ) Are arranged in a fan shape at a time, and the water depth is measured at 90 ° width at a time, that is, twice the water depth. The sounding data recording and displaying device 7 displays and records the water depth measured by the multibeam sounding sonar 6. The hull sway correction device 8 measures vertical fluctuation (heaving), bowing (pitching), and swaying (rolling) with respect to the bow of the ship. The sound speed sensor 9 is for lowering the sensor from the ship to the sea floor and measuring the sound speed at an arbitrary depth. The tilt sensor 10 is provided with a tilt sensor for measuring a tilt angle by a non-contact potentiometer on two axes, and is integrally incorporated into a pipe 22 to which a transducer of the multi-beam sounding sonar 6 is attached, so that the tilt of the direct transducer can be obtained. Is measured. Tilt monitor 1
Reference numeral 1 denotes a graphic display of the inclination angle in real time, and recording of a change in the inclination angle for monitoring of the transmitter / receiver at the time of outfitting and for correcting terrain data.

The recorded data processing device 15 processes the data recorded in the data recording file 2 of the data recording device 1 to correct the sounding position and the water depth, and to perform a water depth map, an equal depth diagram, a sectional view, A bird's eye view, soil volume calculation result, and the like are created and output, and FIG. 3 shows a flow of the processing. As described above, the data recording file 2 includes, as recorded data, water depth (60 points in a range of 45 ° left and right centered immediately below), hull sway (rolling, pitching, heaving), ship position, bow azimuth, sound The data of the speed and the tilt angle of the two axes with respect to the hull of the sonar head are recorded together with each measurement time. Therefore, the recorded data processing device 15 first performs a sounding position correction process based on the data of the ship position, heading azimuth angle, inclination angle, pitching, and rolling (step S11) as shown in FIG. A water depth correction process is performed based on the speed and heaving data (step S12), and an XYZ file is created (step S13). Note that the tide level is corrected using the actual measurement value at the tide station, but can also be input by inputting the predicted tide level. In addition, the position data measured by the RTKGPS positioning device 3 includes error data. Therefore, with respect to the error data, data indicating an abnormal value is extracted from the values before and after, and is automatically deleted by the ship position error removal software (step S14). Step S
15) Output a water depth map, iso-deep map, cross-sectional view, soil volume calculation result, etc. (step S16), or output an iso-deep map, bird's-eye view, etc. by three-dimensional image processing (step S17) (step S18).

As described above, according to the present invention, in order to improve the reliability of high-density water depth data, an RTK
Although high measurement accuracy is ensured using the GPS positioning device 3, if the angle of inclination between the transducer and the hull is incorrect or changes due to ship speed or sea conditions, the position to be measured becomes uncertain and the sounding accuracy Worsens. For this reason, a tilt sensor 10 and a tilt monitor 11 are provided as a transmitter / receiver tilt monitoring system, and the transmitter / receiver tilt is monitored by these to perform correction based on the tilt.

In order to improve the reliability of high-density water depth data, high-precision position measurement is required, and it has been difficult for a radio position locator or DGPS to bring out the high performance of this depth finder, but RTKGPS. This has been made possible by incorporating a positioning device into the system. RTKGPS
The positioning device has a radio positioning device or DGPS measurement accuracy of 1-2.
It is as high as several cm compared to about m.

FIG. 4 is a diagram for explaining the sounding position correction processing. As shown in FIG. 4, the azimuth of the bow is a, the pitching is P, the rolling is R, and the inclination is T ₁ (as viewed from the bow direction). the clockwise and positive), T ₂ (a positive clockwise from the port to see the starboard), Q ₁ 60 point of sounding position from the port side, ......, Q _n, ......, and the Q _60, correction of sounding position of FIG. 3 (step S11) _{is, Q nX = X + Z n} · tan [45.1-1.5 (n-1) + α] si
n (a) + β Q _nY = Y + Z _n · tan [45.1−1.5 (n−1) + α] co
is performed by using the equation s (a) + γ α = R + T 1 β = Z n · tan (P + T 2) · sin (a) γ = Z n · tan (P + T 2) · cos (a). The water depth is Z,
Heaving is H, tide level is TID, sound velocity correction coefficient is K ₁ ,
Assuming that K ₂ , the correction of the water depth in FIG. 3 (step S12)
Is implemented by using the equation Z = K ₁ · Z + K ₂ -TID-H.

FIG. 5 is a diagram showing an output example of a tilt angle monitor screen of the transmitter / receiver tilt monitoring system.
Taking the horizontal axis as time (A), the inclination angle T ₁ (X direction),
(B) shows an output example of the tilt angle T ₂ (Y direction). When the multibeam sounding sonar 6 is fitted to a ship, the result of the low-pass filter is displayed on the screen of the tilt angle monitor 11 in real time so that the tilt angles of the transducer and the hull can be grasped, and the mounting state is checked. Information is provided to reduce the angle of inclination during adjustment. For example, when a low-pass filter is applied to the output example shown in FIG. 5, the average value thereof is -2.156251 °, and
Since the inclination angles of 0.71445 ° are displayed, the mounting state is adjusted so that these inclination angles are reduced. During the survey, the change in the inclination angle between the transducer and the hull due to loose fittings or contact with obstacles as shown in Fig. 5 was recorded, and this data was analyzed to process the seafloor topographic data. use.

In three-dimensional surveying using the narrow multibeam bathymetry system, the most important issue is to control the inclination of the pipe 22 to which the transducer (underwater head) of the multibeam sonar 6 is attached. This is because it is impossible to know from which position on the sea floor the data is being acquired from the data in the state where the pipe 22 to which the transducer is attached is inclined. To perform more accurate surveying, it is necessary to constantly monitor the inclination of the transducer and perform two-dimensional position correction. What makes this possible is a transducer tilt monitoring system comprising a tilt sensor 10 and a tilt monitor 11.

The inclination of the transducer is managed before leaving the port, after entering the port, and during surveying, and all data is managed in a file.
If there is no change in the inclination value of the transducer before and after departure and after entering the port, use that value, and if the transducer is abnormal during movement for any reason during the survey, , And the average value of the inclination correction data is obtained for correction. In the case of a special sea area with a rapid current, an average value of the inclination correction data for each measurement line direction may be used. In multibeam sounding, oblique sounding is also performed at twice the width of the water depth. However, when the water depth is deep, refraction correction of sound waves by oblique sounding is necessary, and the accurate sound wave propagation velocity in water is measured. There is a need. For example, a digiva is used to obtain a value required for sound speed correction.

FIG. 6 is a diagram showing a comparison example of water depth values obtained by a normal sounding sounder and a multibeam sounding system.
FIG. 6A is a diagram showing an example of data obtained by a conventional system having no tilt monitoring system, and FIG. 6B is a diagram showing data obtained by correcting the tilt of the transducer based on the value obtained by the tilt monitoring system. It is a figure showing an example. According to the data shown in FIG. 6 (A), the standard deviation value obtained by assuming that the error distribution follows the normal distribution in the sea area data at a water depth of 13 to 15 m indicates that the position error is within 16.8 cm at a position error of 0 m. , And 25.0 cm including a position error of 1 m. On the other hand, FIG.
According to the data shown in the above, the standard deviation value is 2 in the sea area at a depth of 55 to 58 m including the one with a position error of 1 m.
It is within 2.4 cm. Judging from this result, it can be understood that the position accuracy of the water depth is increased by performing the inclination correction even when the deep water is taken into consideration.

FIG. 7 is a diagram showing an output example of a water depth map (shallow depth map), in which the water depth values are indicated by a mesh along the wake. FIG. 8 is a diagram showing an output example of an iso-deep map, and FIG. 9 is a diagram showing a volume along with an allowable range. Further, by changing the color tone according to the depth, it is possible to make the image more visually recognizable. By color-coding the difference between the topography in the two seasons and the difference in landfill and dredging from the planned water depth, it can be used for landform change and the management of landfill and dredging work volume.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, pitching, rolling, and heaving are measured by the hull sway correction device, and the tilt angle between the hull and the transducer of the multibeam sounding sonar is measured by the inclinometer, and based on those measured values. Although the correction is performed, the hull sway correction device may measure only heaving, and perform similar measurements by performing measurements including pitching, rolling, and heaving with an inclinometer. Although described as a system for processing seafloor topographic data, the underwater head (transducer) of the multi-beam sounding sonar 6 is attached not at the bottom but at an angle,
It can also be used for surveying the walls of quays and breakwaters, piers, footings, and bases, and is widely used for maintenance and management of harbor structures, dredging and reclamation yield management, port burial and erosion countermeasures, etc. Can be. As a means for measuring the position of a ship, G that measures the position of the ship using radio waves from artificial satellites
Although the PS is illustrated, other positioning systems that use light, radio waves, and sound waves as signals, such as a light wave positioning system and a radio wave positioning system, may be used, or only the conventional narrow multi-beam bathymetry system shown in FIG. Without, even in a bathymetry system with other configurations, if a tilt angle measuring means for measuring the tilt angle is provided when equipping a multi-beam sounding sonar,
It goes without saying that the sounding position can be corrected.

[0022]

As is apparent from the above description, according to the present invention, in the multi-beam sounding sonar, the inclination of the sonar head (transducer / receiver) during the sounding operation is limited by the ship speed and sea conditions due to the sharp beam width. Depending on the condition, the sounding accuracy may be degraded, but the sounding accuracy can be improved by attaching a two-axis inclinometer to the transducer and performing processing using this inclination angle. Therefore, even when the narrow multi-beam bathymetry system that captures seafloor information with high accuracy and area is equipped on small vessels that differ from field to field, ship speed,
It is possible to prevent the inclination angle between the transmitter / receiver and the hull from being changed due to the sea condition, thereby preventing the sounding accuracy from deteriorating, thereby obtaining highly accurate seafloor topographic data.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a narrow multibeam bathymetry system according to the present invention.

FIG. 2 is a diagram showing a state in which a multibeam sounding sonar of the narrow multibeam bathymetry system according to the present invention is fitted to a small vessel or the like.

FIG. 3 is a diagram for explaining a processing flow of a recorded data processing device.

FIG. 4 is a diagram for explaining a sounding position correction process.

FIG. 5 is a diagram showing an output example of a tilt angle monitor screen of the transducer tilt monitoring system.

FIG. 6 is a diagram illustrating a comparative example of water depth values obtained by a normal sounding sounder and a multibeam sounding system.

FIG. 7 is a diagram illustrating an output example of a water depth map (shallow depth map).

FIG. 8 is a diagram showing an output example of a shallow depth map.

FIG. 9 is a diagram showing a work volume together with an allowable range.

FIG. 10 is a diagram for explaining a conventional example of a narrow multibeam bathymetry system.

[Explanation of symbols]

1. Data recording device 2. Data recording file 3. R
TKGPS positioning device, 4 ... positioning data recording and display device, 5
... Azimuth compass, 6 ... Multi-beam sounding sonar, 7 ... Sounding data recording and display device, 8 ... Ship hull correction device, 9 ... Sound speed sensor, 10 ... Tilt sensor, 11 ... Tilt angle monitor,
15: Recorded data processing device, 21: Ship, 22: Pipe

Claims (10)

[Claims] 1. A multi-beam sounding sonar for measuring water depth by arranging a plurality of sound wave transmitters and receivers in a fan shape on a ship, and integrally mounting with the transmitter and receiver of the multi-beam sounding sonar for mounting on a ship. Tilt angle measuring means for measuring the tilt angle of the transducer with respect to the ship, ship position measuring means for measuring the ship position, azimuth means for measuring the azimuth angle of the bow, and pitching, rolling, measuring the motion of the ship comprising heaving Ship sway measurement means, sound velocity measurement means for measuring sound velocity according to the water depth, and measurement data recording means for recording the measurement data, the ship position, azimuth angle of the bow, inclination angle, pitching, Correction of sounding position by the multi-beam sounding sonar based on rolling, correction of water depth by the multi-beam sounding sonar based on the sound velocity, heaving and tide level A multi-beam bathymetry system. 2. The multi-beam bathymetry system according to claim 1, wherein said tilt angle measuring means includes means for displaying tilt angle data. 3. The multi-beam bathymetry system according to claim 2, wherein tilt angle data to which a low-pass filter has been applied can be displayed. 4. The tilt angle measuring means incorporates a biaxial tilt sensor into a pipe to which the transducer is attached,
2. The multi-beam bathymetry system according to claim 1, wherein the system measures a tilt angle between the transducer and the ship. 5. The multi-beam bathymetry system according to claim 1, wherein the tide level is an actual measurement value or a predicted tide level at a tide station. 6. A multi-beam sounding sonar equipped with a plurality of sound wave transmitters and receivers arranged in a fan shape for measuring water depth, and mounted integrally with the multi-beam sounding sonar transmitter and receiver. Tilt angle measuring means for measuring the tilt angle of the transducer, ship position measuring means for measuring the ship position, azimuth means for measuring the azimuth angle of the bow, and sway measuring means for measuring the vertical sway of the ship, A sound velocity measuring means for measuring a sound velocity according to the water depth, and a measurement data recording means for recording the respective measurement data, the sounding by the multi-beam sounding sonar based on the ship position, the azimuth angle of the bow, and the inclination angle. A multi-beam bathymetry system, wherein the position is corrected, and the water depth is corrected by the multi-beam sounding sonar based on the sound velocity, the vertical motion of the ship, and the tide level. 7. The multi-beam bathymetry system according to claim 6, wherein said tilt angle measuring means has means for displaying tilt angle data. 8. The multi-beam bathymetry system according to claim 7, wherein tilt angle data subjected to a low-pass filter can be displayed. 9. The multi-beam bathymetry system according to claim 6, wherein the tide level is an actual measurement value or a predicted tide level at a tide station. 10. A multi-beam bathymetry system in which a multibeam sounding sonar in which a plurality of sound wave transducers are arranged in a fan shape is fitted to a ship, emits an acoustic beam, acquires water depth data, and performs surface bathymetry. There is provided a tilt angle measuring means attached to the transducer of the multi-beam sounding sonar and fitted to a ship to measure the tilt angle of the transducer, and a display means for displaying the measured tilt angle data, When the transmitter / receiver of the multibeam sounding sonar is fitted, the display means displays the inclination angle data subjected to a low-pass filter, and at the time of bathymetry, the change of the inclination angle data is displayed and recorded to perform the sounding position. A multi-beam bathymetry system characterized by correcting the water depth.