JPH09304064A - Tide gauge - Google Patents

Abstract

(57) [Abstract] [Problem] In conventional tide level observation, it is difficult to install the float because the float must be installed while restraining the horizontal movement, and tide level observation is basically based on the relative location of the installation location. Since it is a measurement, there is a problem that a separate calibration is required when measuring the tide level at a certain standard point. A GPS antenna 3 is installed at a reference position,
This antenna 3 collects radio waves from a plurality of satellites to position the antenna position, calculates the difference between the positioned antenna position and the reference position, and outputs the difference as correction information. , The floating body moored on the sea surface at the tide level observation position and the GPS antenna 12 installed on this floating body collect radio waves from a plurality of satellites to measure the floating body position, and input from this floating body position and the ground positioning device 4. The tide gauge 1 including a floating body positioning device that measures the tide level based on the corrected information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tide level observation device for observing a tide level.

[0002]

2. Description of the Related Art Conventional tide level observation is carried out by taking out the ups and downs of a float restrained in horizontal movement to the outside with a wire or the like that can follow the movement of the float attached to the float, and using a pen or the like to take the movement. Record directly, or after converting its movement into an electric signal with a potentiometer, record it with an electric pen recorder (eg, electromagnetic oscilloscope), or convert the electric signal into an analog-digital signal and record it digitally. Was.

When it is necessary to easily record changes in tide level at a reclamation site, etc., a fixed point (a position above the water surface where the water surface can be seen immediately below the water surface) is arbitrarily set on a solid revetment near the site. The distance from the fixed point to the water surface,
Positions were measured with a plumb bob or a measure to measure changes in tide level.

[0004]

However, in the conventional tide level observation, it is difficult to install the float because it is necessary to install the float while constraining the horizontal movement, and the tide level observation is basically performed at the installation location. However, there is a problem that a separate calibration is required when measuring the tide level at a certain standard point.

Therefore, an object of the present invention is to provide a tide level observation apparatus which is easy to install and does not require calibration.

[0006]

In order to achieve the above-mentioned object, the tide level observation apparatus of the first aspect of the present invention uses an antenna installed at a reference position to collect radio waves from a plurality of satellites and position the antenna position. Then, a ground positioning device that calculates the difference between the positioned antenna position and the reference position and outputs this difference as correction information, a floating body moored to the sea surface at the tide level observation position, and installed on the floating body With the antenna, the radio waves are collected from multiple satellites to measure the position of the floating body,
The present invention is characterized by including a floating body positioning device that measures a tide level based on the floating body position and correction information input from the ground positioning device.

According to the configuration of the first aspect of the present invention, the correction information is obtained from the antenna position measured by the ground positioning device and the installed antenna reference position, and the floating body position and the correction information measured by the floating body positioning device. Based on, the accurate tide level is observed.

The tide level observing device of the second aspect of the present invention is the tide level observing device of the first aspect of the invention, characterized in that the height position of the antenna of the floating body positioning device is made to coincide with the sea level. .

According to the second aspect of the present invention described above, the height position of the sea surface is eliminated by matching the height position of the antenna with the sea surface, thereby eliminating the geometrical error caused by the tilt of the antenna due to the shaking. Is measured directly.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a layout diagram of a tide level observation apparatus according to an embodiment of the present invention.

Reference numeral 1 is a tide gauge (tidal station) installed at a tide level observation position, and is moored to the tip of a jetty 2 projecting from land A to sea B, for example. On land A, 3
A global positioning system (hereinafter abbreviated as GPS) antenna 3 installed at a known point where dimensional coordinates (longitude, latitude, height) are accurately measured (at least height is accurate); A ground positioning device (fixed station) 4 connected to the GPS antenna 3 is provided. The terrestrial positioning device 4 uses a transmission antenna as described later.
Since correction information is transmitted to the tide gauge 1 by radio waves from 33, it is desirable to install it in a position where the tide gauge 1 can be seen through. In FIG. 1, 5 indicates a coastline.

As shown in FIG. 2, the tide gauge 1 is a floating body.
11, a GPS antenna 12 arranged on the surface of the floating body,
Floating body positioning device 13 built in the floating body 11 (details will be described later)
A wave shield cover 14 that transmits radio waves and protects the GPS antenna 12 and the floating body positioning device 13 from seawater splashes;
It consists of a mooring line 15 mooring between the jetty 2 and the jetty 2, and a mooring anchor weight 17 attached to the end of a mooring anchor line 16 for adjusting the surface position (height of the sway center) of the floating body 11 to the sea level position. There is. By making the height of the swaying center coincide with the sea level by the mooring anchor weight 17, the height position of the GPS antenna 12 coincides with the sea level, and the geometrical error caused by the inclination of the GPS antenna 12 due to the swaying occurs. Can be removed and the height of the sea surface can be directly measured. Further, a receiving antenna 22 connected to the floating body positioning device 13 is erected on the floating body 11.

As shown in FIG. 3, the floating body positioning device 13 collects radio waves from a plurality of satellites (e.g., 8) via the GPS antenna 12 at intervals of, for example, 1 s to determine the antenna position (three-dimensional coordinate). A GPS receiver 21 for positioning and a receiving antenna for receiving radio waves transmitted from the ground positioning device 4.
22, a data receiver 23 for receiving correction information (details will be described later) transmitted from the ground positioning device 3 via the receiving antenna 22, and an antenna position (three-dimensional coordinate) output from the GPS receiver 21. Based on the correction information output from the data receiver 23 and the three-dimensional coordinates (longitude, latitude, height) of the tide gauge 1 by the real-time kinematic mode (RTK) method capable of relative positioning with an accuracy of about 1 mm. Calculate,
It is composed of a data processor 24 for outputting and a recording / display device 25 for recording and displaying the data output by the data processor 24. The recording / display device 25 records data on a recording medium such as a floppy disk, a hard disk, a magneto-optical disk, and displays it on a display such as a CRT, a printer, or a plotter.

The terrestrial positioning device 4 also collects radio waves from a plurality of (for example, eight) satellites via the GPS antenna 3 at intervals of, for example, 1 s to measure the antenna position (three-dimensional coordinates) 31. And the height of the GPS antenna 3 and the coordinates of the known point that have been accurately measured in advance are set, and the difference between these set values and the antenna position (three-dimensional coordinates) output from the GPS receiver 31, that is, correction information And a transmitting antenna 33, and a transmitter 34 for transmitting the correction information output by the data processor 32 to the tide gauge 1 via the transmitting antenna 33.

The operation of the above configuration will be described. First, the operation of the ground positioning device 4 will be described. GPS antenna 3
When the radio wave from the GPS satellite is received by the GPS receiver 31, the radio wave is demodulated by the GPS receiver 31, and the information, that is, the antenna position (three-dimensional coordinate) is output to the data processor 32. In the data processor 32, a difference from the preset setting value {antenna position (three-dimensional coordinate)}, that is, correction information is calculated, shaped into a format suitable for transmission, and output to the transmitter 34. The transmitter 34 modulates the input correction information and outputs the modulated correction information to the transmission antenna 33.
Sent from the air.

Next, the operation of the tide gauge 1 will be described.
When the GPS antenna 12 receives a radio wave from a GPS satellite, the GPS receiver 21 demodulates the radio wave, and the information, that is, the antenna position (three-dimensional coordinate) is output to the data processor 24. Further, the reception antenna 22 receives the radio wave transmitted from the ground positioning device 4, the data receiver 23 demodulates it into correction information, and the correction information is output to the data processor 24.

The data processor 24 includes an antenna position (three-dimensional coordinate) output from the GPS receiver 21 and the data receiver 23.
Based on the correction information output from, the real-time kinematic mode signal processing is performed to calculate the three-dimensional coordinates (longitude, latitude, height) of the tide gauge 1. Further, if necessary, correction calculation is performed on the height and the result is output to the recording / display device 25.

Usually, the tide level is determined on the basis of the average sea level of Tokyo Bay. In a region or the like, when obtaining a tide level change based on the average sea level of the region, it is necessary to perform a calculation to correct the difference between the average sea level of Tokyo Bay and the average sea level of the region.

The recording / display unit 25 records the input three-dimensional coordinates (longitude, latitude, height) together with the current time on the recording medium and displays it on the display. As described above, by mounting the GPS antenna 12 on the floating body 11 so that the GPS antenna 12 can move up and down according to the change in the tide level, the displacement in the vertical axis direction, that is, the tide level can be observed. Further, since the tide gauge 1 can be installed only by mooring, it can be easily installed.

In addition, since positioning by GPS can measure every second, continuous measurement can be performed with high accuracy,
Furthermore, since three-dimensional coordinates are measured by GPS positioning, it is possible to continuously measure the tide level even if there is horizontal movement. Further, since the GPS antenna 12 is small and lightweight, the floating body 11 having the GPS antenna 12 attached thereto is moored so as not to be swept by tidal currents even when observing a tide level change due to temporary installation of a device, such as at an ocean civil engineering site. It is possible to observe the tide level by itself, and it is possible to save the labor required for installation. In addition, since positioning by GPS is essentially measurement using a computer, continuous data collection and unmanned automatic measurement can be performed.

In addition, the positioning by GPS is possible by absolute positioning by a coordinate system unique to GPS called WG84,
By linear transformation, it can be converted to the geodetic coordinate system adopted in each country or the public coordinate system in Japan, and the average sea level value of the main sea level is already clear according to the coordinate system used in that region. Therefore, it is possible to obtain the change in the tide level with respect to the average sea level in the area without special calibration.

Although the correction information is transmitted by radio waves in the present embodiment, the ground positioning device 4 and the tide gauge 1 are used.
If they are close to each other, wired transmission may be performed. Also,
Although the record / display device 25 is provided in the tide gauge 1, it may be provided not in the tide gauge 1 but on the ground positioning device 4 side so that the tide level data can be transmitted and recorded / displayed from the tide gauge 1. ,
Furthermore, the antenna position output from the GPS receiver 21 (3
The dimensional coordinate) information may be transmitted to the ground positioning device 4 side, and the ground positioning device 4 may perform signal processing based on the correction information to obtain the tide level result.

Further, although the height of the GPS antenna 12 is made to coincide with the sea surface, the antenna 12 may be affected by sea water splashes and waves.
G to prevent the tide level from being interrupted
It is also possible to install the PS antenna 12 at a position higher than the floating body 11 by means of a column or the like, and remove an error due to shaking by detecting the tilt with an inclinometer or a gyro and performing signal processing.

[0024]

As described above, according to the first aspect of the present invention, the correction information is obtained from the antenna position measured by the terrestrial positioning device and the antenna reference position, and the correction information is measured by the floating body positioning device. Accurate tide level can be observed based on the floating body position. In addition, positioning by collecting radio waves from a plurality of satellites, that is, positioning by GPS can be performed every second, and continuous measurement can be performed with high accuracy, and even if there is horizontal movement, it can be continuously measured. The tide level can be measured. In addition, since the GPS antenna is small and lightweight, the GP can be used even when observing changes in tide level due to temporary installation of equipment, such as at an offshore construction site.
The tide level can be observed simply by mooring the floating body with the S antenna attached so that it will not be swept away by tidal currents, and the labor required for installation can be saved. In addition, since positioning by GPS is essentially measurement using a computer, continuous data collection and unmanned automatic measurement can be performed.

According to the second aspect of the present invention, the height position of the sea surface can be eliminated by matching the height position of the antenna with the sea surface, thereby eliminating the geometrical error caused by the tilt of the antenna due to the shaking. Can be directly measured, and it is not necessary to detect the tilt error by the inclinometer or the gyro and remove the error by signal processing, so that a simple and inexpensive device can be provided.

[Brief description of drawings]

FIG. 1 is a layout diagram of a tide level observation apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a tide gauge of the same tide gauge observation apparatus.

FIG. 3 is a block diagram of a tidal level observation apparatus.

[Explanation of symbols]

 A Land B Sea 1 Tide gauge 2 Jetty 3,12 GPS antenna 4 Ground positioning device 11 Floating body 13 Floating body positioning device 14 Wave shield cover 15 Mooring line 16 Mooring anchor line 17 Mooring anchor weight 21, 31 GPS receiver 22 Reception antenna 23 Reception Machine 24, 32 Data processor 25 Record display device 33 Transmitting antenna 34 Transmitter

Claims (2)

[Claims] 1. An antenna installed at a reference position,
Collecting radio waves from multiple satellites and positioning the antenna position,
A ground positioning device that calculates the difference between the positioned antenna position and the reference position and outputs this difference as correction information, a floating body moored at the sea level at the tide level observation position, and a floating body installed on the floating body An antenna is used to collect radio waves from a plurality of satellites to measure the position of the floating body, and a floating body positioning device that measures the tide level based on the floating body position and the correction information input from the ground positioning device. Tide level observation device. 2. The tide level observation apparatus according to claim 1, wherein the height position of the antenna of the floating body positioning apparatus is made to coincide with the sea level.