JP2003014455A - Topographic surveying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and precisely survey the landform of a tidal zone without depending on aerial surveying, radar or photographic surveying, or surveying with sounding lead. SOLUTION: A survey ship 1 is navigated to the vicinity of a land-fill layer B, a support rod 3 having a GPS antenna 2 mounted on the tip is extended from the survey ship 1 to the land-fill layer B side, and a weight 5 at the lower end of a rod 4 suspended from the GPS antenna 2 is positioned in a water edge. The weight 5 is moved along the water edge line by the navigation of the ship 1 and the operation of the support rod 3 by a worker, the horizontal position data of the water edge line are determined with the survey ship 1 as the movable station of a GPS positioning system, and the horizontal position data are accumulated every tidal level to grasp the landform of the tidal zone similarly to contour lines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring topography in a shallow sea area, and more particularly to a GPS (Global Positioning System) for terrain in a tidal zone affected by tides.
m) concerning the method of surveying.

[0002]

2. Description of the Related Art For example, in sea reclamation work, sound depth surveying is performed by an acoustic sounder for the purpose of determining the place and amount of sediment input. It is useful to accurately grasp the terrain of the tidal zone that appears on the sea at low tide and sinks to the sea surface at high tide. However, since the acoustic sounding machine is required to transmit underwater, it cannot be used in shallow water such as the tidal zone. There was a constraint that we had to rely on radar or photogrammetry from the turret, or red surveying.

[0003]

However, according to the above-mentioned aerial survey, it takes a high cost to fly the aircraft, and it takes a long time to process the data. When surveying was required, it could not be applied at all. Moreover, according to radar or photogrammetry from the above high turret, in addition to the fact that the surveying range is significantly limited, accurate surveying is difficult, and according to the surveying by red, red is stable at the water's edge. It was almost impossible to operate, and in reality, there was no choice but to give up surveying tidal zones.

The present invention has been made in view of the above technical background, and its object is to target the tidal zone without relying on aerial surveying, radar or photogrammetry, surveying by red, etc. It is to provide a surveying method capable of surveying the terrain easily and accurately.

[0005]

In order to solve the above-mentioned problems, the present invention moves a GPS antenna along the waterfront of a survey area and obtains horizontal position data of the waterfront by a GPS positioning system, The horizontal position data is accumulated for each tide level. According to the topographical survey method performed in this manner, the horizontal position data of the waterfront can be accurately obtained by the GPS positioning system, and therefore the movement of the GPS antenna along the waterfront is performed a plurality of times between low tide and high tide. By doing so, it is possible to obtain the terrain for each tide level as with contour lines. In this case, it is desirable to identify the tide level in association with the time included in the GPS signal, which allows the tide level to be accurately identified in correspondence with the horizontal position survey time of the GPS positioning system. In the present invention, G along the shoreline
The method of moving the PS antenna is arbitrary, and a method of operating the GPS antenna from the ship or a method of operating from the land can be adopted.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show one embodiment of the topographic survey method according to the present invention. In this embodiment, the landform of the tidal zone of the reclaimed layer B created by pouring earth and sand on the seabed A surrounded by the seawall (not shown), that is, between the highest tide level HWL and the lowest tide level LWL It is intended to measure the topography of. At the time of surveying the topography of the tidal zone, as shown in FIG. 1, the survey ship 1 is put in the vicinity of the landfill layer B, and from this survey ship 1 to the landfill layer B side,
A support rod 3 having a GPS antenna 2 attached to its tip is extended, a weight 5 at the lower end of a rod 4 hanging from the GPS antenna 2 is positioned at the water's edge, and navigation of the survey ship 1 and operation of the support rod 3 by an operator are performed. And move the weight 5 along the waterfront line. Here, the GPS antenna 2 is swingably attached to the tip end of the support rod 1, so that the rod 4 having the weight 5 at the lower end maintains a state of standing upright in the vertical direction. , Plane weight 5
It will move along the waterfront along with. In addition,
The support rod 3 may be one that telescopically expands and contracts.

On the other hand, on the surveying vessel 1, as shown in FIG. 2, a GPS receiver 6 which takes in a GPS signal from the GPS antenna 2 and a correction wirelessly transmitted from a reference station 10 whose accurate position is known. Data receiving antenna 7 for receiving data
And a data receiver 8 that takes in correction data from the data receiving antenna 7, and an arithmetic processing unit that obtains the horizontal position of the weight 5 based on the data taken in from the GPS receiver 6 and the data receiver 8. (PC) 9 is mounted, and the surveying vessel 1 is configured as a mobile station including the GPS antenna 2. The reference station 10
Includes a GPS antenna, a GPS receiver, a data transmitter, a data transmission antenna, etc., but these are not shown.

The mobile station 1 and the reference station 10 form a GPS positioning system together with a plurality of satellites 11. G
The PS positioning system usually has a function of solving a four-dimensional simultaneous equation based on GPS signals acquired from four or more satellites 11 to position a three-dimensional position. Since it is sufficient to calculate the directional position (two-dimensional position), it is sufficient to use the signals of the three satellites 11.
Therefore, in the present embodiment, the arithmetic processing unit 9 stores the correlation between the time and the tide level in advance, and
The topography for each tide level is calculated based on the horizontal position data of the weight 5 obtained by the positioning system and the tide level data. In this case, G transmitted from the satellite 11
Since the PS signal has an element of time, here, the arithmetic processing unit 9 is provided with a function of identifying the tide level according to the time included in the GPS signal so that the above-mentioned terrain operation is automatically executed. .

When measuring the landform of the landfill layer B, as described above, the weight 5 or the GPS antenna 3 is moved along the waterfront line of the landfill layer B, and the horizontal position of the waterline is continuously determined by the GPS positioning system. However, in the present embodiment, this movement is executed a plurality of times including high tide and low tide. Since the time widths of high tide and low tide are each about 2 hours, the weight 5 (GPS antenna 3) can normally be moved along the entire waterfront line within this time. Therefore, the positioning data (horizontal position data) at high tide and low tide by the GPS positioning system represents the landform of the landfill layer B at high tide and low tide as it is, and the process of collecting positioning data for each tide level is performed. It becomes unnecessary. On the other hand, in the time zone between the high tide and the low tide, since the tide level changes with time, the weight 5 (GP
The positioning data obtained by moving the S antenna 3) does not directly represent the landform of the landfill layer B. However, in the present embodiment, the weight 5 is moved a plurality of times in the time zone between the high tide and the low tide, so the arithmetic processing unit 9 stores the tide level data for each time stored in advance. By referring to this, a process of collecting positioning data for each tide level is performed, and as a result, a terrain for each tide level can be obtained in the same manner as contour lines.

In the present embodiment, since the relative positioning method with respect to the reference station 10 is adopted as the positioning method by the GPS positioning system, the positioning data has extremely high accuracy (± several cm as an example) and landfill. The topography of the tidal zone of layer B can be grasped with high accuracy, and therefore it is very useful for determining the place and amount of sediment input in the landfill work.

In the above embodiment, the support rod 3 is extended from above the survey ship 1 to move the GPS antenna 2 along the waterfront line. However, the present invention relies on the survey ship 1. Instead, operate the support rod 3 from land and use GPS
The antenna 2 may be moved along the waterfront line. In this case, the GPS that constitutes the GPS positioning system
The receiver 6, the data receiving antenna 7, the data receiver 8, the arithmetic processing unit (notebook personal computer is possible) 9 and the like are unitized in appropriate units to enhance portability. Further, the scope of application of the present invention is not limited to the topographical survey of the landfill layer B in the above-mentioned landfill construction. It can be easily applied to surveying.

[0013]

As described above in detail, according to the terrain surveying method of the present invention, by incorporating the tide level data into the positioning data by the GPS positioning system, the terrain can be easily and accurately targeted at the tidal zone. It will be very useful for landfill construction management and grasp of coastline deformation due to natural disasters.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a topographical survey method according to the present invention.

FIG. 2 is a block diagram showing the structure of a GPS positioning system used in the present invention.

[Explanation of symbols]

1 Survey ship (mobile station) 2 GPS antenna 3 support rods 4 rod 5 weights 10 reference stations 11 satellites A seabed B Landfill layer

Claims (4)

[Claims] 1. A GPS antenna is moved along a waterfront line of a survey area to obtain horizontal position data of the waterfront line by a GPS positioning system, and the horizontal position data is accumulated for each tide level. Topographic survey method. 2. The topographic survey method according to claim 1, wherein the tide level is specified in association with the time included in the GPS signal. 3. The topographical survey method according to claim 1, wherein the GPS antenna is operated from the ship. 4. The topographic survey method according to claim 1, wherein the GPS antenna is operated from the land.