KR100292302B1 - System for measuring water level and pondage in real-time by using global positioning system carrier - Google Patents

Abstract

PURPOSE: A system for measuring a water level and a pondage in real-time by using a GSP(Global Positioning System) carrier is provided to measure the water level and the pondage of a dam and a lake in real-time by constructing a DGSP(Differential Global Positioning System) using the GSP carrier. CONSTITUTION: GPS antennas(5a,6a) are respectively arranged on at least two floating members(6) positioned on a fixed position or surface of a dam(5) and receive a plurality of GPS carriers transmitted from a plurality of GPS satellites(1). A GPS receiver(2) receives the GPS carriers from the GPS antennas(5a,6a) and calculates a position of the respective GPS antennas(5a,6a). An arithmetic unit measures a level and a flow of water around the respective floating members(6) by using position information of the respective GPS antennas(5a,6a) and calculates the whole pondage stored in the dam(5) by using level information of the water. An output unit(8) displays a screen the water level, the whole pondage, and the flow of water outputted from the arithmetic unit.

Description

Real-time water level and low water measurement system using GPS carrier

The present invention relates to a real-time water level and low water measurement system using a GPS (Global Positioning System) carrier, and in particular, serves as a buoy and a DGPS (Differential GPS) reference station floating on the surface of a GPS carrier transmitted from a GPS satellite. The present invention relates to a real-time water level and low water measurement system using a GPS carrier used to measure the water level and low water level of a dam by receiving GPS antennas respectively installed in the dam and comparing the received data values.

Storage management of dams, lakes and reservoirs is closely related to the efficient use of water resources and flood protection. In particular, in the case of Korea, where the rainy season and the dry season are clearly distinguished, it is very economically important to effectively manage the limited water resources by correctly identifying and managing the low volume and the manageable capacity during the rainy season.

However, in the related art, most of the primitive methods of reading this important water resource management by reading the scale marked on the dam are mostly used, and a method of measuring the depth of water using an ultrasonic sensor is partially used. However, as shown in FIG. 4, since the low water measurement through the depth measurement using the ultrasonic sensor uses a time difference from which the ultrasonic wave incident on the bottom surface is reflected, when the shape of the bottom surface of the measurement portion is irregular, The disadvantage is that it is calculated differently. In addition, in the case of using an automated system using an ultrasonic sensor as described above, there are many problems in technical aspects such as not only inefficient management and maintenance of the sensor but also inaccurate measurement values.

In addition, when managing the water resources by reading the scale of the dam, it is necessary to visit each time to measure the water level of the dam.

The present invention has been made to solve the problems of the prior art as described above, by constructing a DGPS using a GPS carrier, GPS that can systematically and efficiently manage the water level and storage of water stored in dams, lakes, reservoirs, etc. The purpose is to provide a real-time water level and low water measurement system using a carrier wave.

1 is a view illustrating a general position measuring principle using a GPS code,

2 is a view for explaining the basic principle of precision displacement measurement using a GPS carrier,

3 is a schematic diagram for explaining the basic principle of the DGPS used to cancel the common error of the GPS,

4 is a schematic diagram briefly showing a water level measuring method using an ultrasonic sensor according to the prior art,

5 is a schematic view for explaining a real-time water level and low water measurement system using a GPS carrier according to an embodiment of the present invention,

FIG. 6 is a block diagram illustrating a real-time water level and low water measurement system using the GPS carrier shown in FIG. 4. FIG.

♠ Explanation of symbols on the main parts of the drawing ♠

1: GPS satellite 2: GPS receiver

3: DGPS Reference Station 5: Dam

5a, 6a: GPS antenna 5b, 6b: data transmission device

6: bui 7: Data receiving device

8: output unit

According to the present invention for achieving the object as described above, using a plurality of GPS carriers transmitted from a plurality of GPS satellites located 20,000km over the air carrier to measure the water level and storage of water stored in dams, lakes, reservoirs, etc. In the real-time water level and low water measurement system using a fixed position, and is fixed to a predetermined position of the dam that serves as a DGPS reference station to receive a plurality of GPS carriers transmitted from the plurality of GPS satellites A GPS receiver that compares the GPS antenna received from the GPS antenna of the flotation device with the GPS antenna disposed in the flotation device, the GPS carrier received from the GPS antenna of the dam, and a data value compared with the GPS receiver. Real time number using a GPS carrier, characterized in that it comprises an output unit for outputting the water level of the dam in real time The storage capacity and the measurement system is provided.

In addition, according to the present invention, by calculating the water level of the dam and the submerged surface of the dam which is a data value compared in the GPS receiver additionally the calculation means for outputting the total reservoir amount stored in the dam through the output unit Provided is a real-time water level and low water measurement system using a GPS carrier, including.

In addition, according to the present invention, by placing a plurality of levitation device with the GPS antenna on the water surface real-time water level using a GPS carrier characterized in that the water flow by observing the water flow by measuring the water level of each of the plurality of levitation device is located And a low flow rate measurement system.

In the following, the contents of the Global Positioning System (GPS) will be described.

Located around 20,000 km and composed of 24 GPS satellites, the GPS is designed to allow an unlimited number of users to observe 4 or more satellites from any location on Earth, so there is a 95% chance that civil users will have a plane error of about 100 meters. You can calculate your position in the range (2drms: distance root mean square). In order to calculate the location using GPS, four basic information is calculated from the three-dimensional position of the GPS receiver and the error of the GPS receiver clock which is much more inaccurate than the atomic clocks such as Cesium and Rubydium mounted on the GPS satellite. Since all four unknowns have to be solved, the location must be calculated based on data from at least four GPS satellites. All 24 GPS satellites used in this way transmit a unique PRN (Pseudo Random Noise) code for each satellite to the user by putting information (navigation messages) such as satellite position coordinates on the carrier. There are two carriers used in this manner, L1 and L2. The frequencies are 1.575 GHz and 1.227 GHz, respectively. Civilians are allowed to receive only L1 and the military can receive both L1 and L2.

In the drawings, FIG. 1 is a view for explaining a general positioning principle using a GPS code.

As shown in FIG. 1, for example, when a user measures the distance between each GPS satellite 1 and the user GPS receiver 2 using a GPS code, the GPS satellite 1 is connected to the GPS receiver 2. By comparing the arriving signal with the signal produced by the user's GPS receiver 2, the time Δt taken until the code leaving the GPS satellite 1 reaches the GPS receiver 2 is measured. Δt) is multiplied by the speed of light C to find the distance between each GPS satellite 1 and the GPS receiver 2 of the user. At this time, the time Δt is calculated by using a correlator, and the length of the cord chip is about 300m, so the correlator developed by the present technology is about 3m, which is about 1% of the length of the code chip. It can be calculated with a degree of resolution (minimum error). However, the calculated distance includes the time delay caused when the radio wave leaving the GPS satellite 1 passes through the ionosphere and the troposphere, and the time delay caused by the multipath caused by the electric wave hitting the object, and the GPS satellite. (1) The error of the GPS receiver (2) clock, as well as the position and the clock-related error, etc. are included, which is called pseudorange.

Considering this general situation, the position error measured by the GPS code is about 100m. Even though this error is different from other navigation systems, the GPS does not accumulate errors, and the GPS receiver price is getting cheaper. As a result, it is expected to be widely used for basic navigation equipment such as automobiles, ships and aircrafts. However, this GPS code has a disadvantage that it is impossible to measure the water level stored in the dam with a resolution of about several centimeters.

2 is a view for explaining the basic principle of the precision displacement measurement using the GPS carrier.

FIG. 2 shows the results of the carrier phase of the signal generated by the satellite, the carrier phase of the satellite signal received by the receiver, and the carrier phase generated by the receiver when the current time t is 0, τ, t. Is shown.

When the current time t is 0, the carrier phase of the signal generated by the satellite, the carrier phase of the satellite signal received by the receiver, and the carrier phase generated by the receiver are all 0, and the current time t is In case of τ, the carrier phase of the signal generated from the satellite is ｆ ^s · τ, the carrier phase of the satellite signal received by the receiver is 0, the carrier phase of the receiver is ｆ _r · τ, and the current time (t When t is), the carrier phase of the signal generated from the satellite is ｆ ^s · t, the carrier phase of the satellite signal received by the receiver is ｆ ^s · (t-τ), and the carrier phase generated by the receiver is ｆ _r T. Here, _r represents a carrier frequency occurring in a receiver, ^s represents a carrier frequency occurring in a satellite, and τ represents a time when a satellite signal departing from the satellite reaches the receiver.

In the case of using the GPS carrier using the principle as described above, the wavelength of the L1 carrier that can be received by civilians is about 19cm, the current technology can distinguish the phase up to about 1% of this wavelength. Therefore, using a GPS carrier, the displacement can be measured with a resolution of about 1.9 mm.

In the drawings, FIG. 3 is a schematic diagram for explaining the basic principle of the DGPS used to cancel the common error of the GPS.

As shown in FIG. 3, since the error of about 100m generated when the position is measured by using a GPS code is largely determined by an error that several receivers have in common, the DGPS eliminates the common errors. It is a way to drastically lower it to around 5m. In brief, the principle is that the DGPS reference station (3), which already knows the location by performing surveying, receives the GPS signal from the GPS satellite (1) and transmits the calculated error to the surrounding user (4). Is a way to reflect this error when calculating its position.

The introduction of DGPS has been widely applied to the fields requiring more accurate position calculation, and the resolution of the code (about 3 m) is limited to the position measurement using the GPS code. It is not available. However, taking advantage of the VLBI (Very Long Baseline Interferometry) method, which has been widely applied to astronomical observation since the early 20th century, when the DGPS is constructed using GPS carriers, the position can be calculated with an error of several cm to several mm. Currently, carrier resolution is known to be about 1.9mm, and the carrier application of this DGPS is expected to be widely applied in geodetic field, earthquake observation, and attitude determination which need precise position calculation.

In the following, with reference to the accompanying drawings, a preferred embodiment of a real-time water level and low water measurement system using a GPS carrier according to the present invention using a GPS carrier having the features as described above will be described in detail.

5 is a schematic diagram illustrating a real time water level and low water level measurement system using a GPS carrier according to an embodiment of the present invention, and FIG. 6 is a real time water level and low water level measurement system using a GPS carrier shown in FIG. 4. It is a block diagram for explanation.

As shown in FIG. 5, 24 GPS satellites 1 are arranged in an area of about 20,000 km, and GPS antennas 5a and 6a receiving GPS carriers transmitted from the GPS satellites 1 are arranged on the ground. 1 is arranged on the upper surface of the buoy 6 floating on the water surface of the reservoir where the water is stored. At this time, a plurality of buoys 6 floating on the water surface may be installed, and the GPS antenna 6a is installed on the upper surface of the buoy 6, respectively. Here, each of the GPS antennas 5a and 6a serves to receive a GPS carrier transmitted from the GPS satellite 1. The GPS carriers respectively received by the GPS antennas 5a and 6a which play this role are input to the data transmission devices 5b and 6b, respectively. The GPS carriers respectively input to the data transmission devices 5b and 6b are transmitted and received by the data reception device 7 respectively.

These data transmission devices 7 are each connected to the GPS receiver 2 by wire. Here, the GPS receiver 2 is a GPS antenna 5a installed on each carrier wave input by the data receiving device 7, that is, a predetermined upper surface of the dam 5, and the buoy 6 floating on the water surface. It serves to compare the respective carriers received from the GPS antenna (6a) installed on the upper surface of the. The GPS receiver 2, which plays such a role, uses an output unit (not shown) to collect data about the data value and the submerged surface compared with the GPS receiver 2, and outputs the water level of the dam and the total reservoir water. 8).

In the following, a method of measuring the water level and the storage amount of water stored in the dam using a GPS carrier will be described.

As shown in Fig. 5 and Fig. 6, a carrier wave is transmitted from a GPS satellite 1 located in the air. Then, the transmitted GPS carriers are respectively received by the GPS antenna 5a provided at the predetermined portion of the dam 5 and the GPS antenna 6a provided on the upper surface of the buoy 6 floating on the water surface. Each carrier wave received at the GPS antennas 5a and 6a installed on the upper surfaces of the dam 5 and the buoy 6, respectively, and received by the data receiving device 7 via the data transmission devices 5b and 6b is wired. The GPS receiver 2 is connected to the GPS receiver 2 connected thereto. When each carrier is transmitted to the GPS receiver 2 in this way, the GPS receiver 2 includes a carrier wave transmitted through the data transmission device 7, that is, a carrier wave received from the GPS antenna 5a installed in the dam 5. The water level is measured by comparing the carriers received by the GPS antenna 6a installed in the buoy 6. That is, the GPS antenna 5a installed in the dam 5 is always fixed to serve as a fixed reference station, that is, a DGPS reference station, and the GPS antenna 6a installed in the buoy 6 is in accordance with the change of the water level. Since the position is configured to fluctuate, it is possible to measure the water level by comparing the altitude difference between these GPS antennas 5a and 6a.

The reason why the altitude difference of the water level can be compared is that the position of the GPS antenna 5a installed on the dam 5 serving as the DGPS reference station is measured and known in advance, and the GPS antenna 5a of the dam 5 is known. This is because if the data value of the received GPS carrier and the previously measured data value are erased, a constant data value can always be calculated. In this way, the variation of the water level is output through the output unit 8 in real time based on the data value compared by the GPS receiver 2. In addition, the total storage amount calculated by using the calculation means (not shown) is calculated through the output unit 8 from the data value compared by the GPS receiver 2 and the collected information about the submerged surface.

In addition, when the buoy 6 having the GPS antenna 6a is installed at various locations in the reservoir where the water is stored to measure the water level, the water level at each buoy 6 can be measured so that the water flow can be measured. You can also observe.

As described in detail above, the real-time water level and low water measurement system using the GPS carrier of the present invention can accurately measure the water level and low water stored in dams, lakes, reservoirs, etc. in real time, and thus, low water quantity management is very systematic and efficient.

In addition, the real-time water level and low water measurement system using the GPS carrier of the present invention can be installed in the water surface of the reservoir to measure the water level by measuring the water level.

In addition, when the low-level water management using the real-time water level and low-water measurement system using the GPS carrier of the present invention, it is not necessary to measure the water level of the dam by visiting every time as in the prior art, thereby reducing the cost due to waste of manpower.

In addition, when the low-level water management using the real-time water level and low-water measurement system using the GPS carrier of the present invention can not only solve the inaccuracies generated when measuring the low water using a conventional ultrasonic sensor, It is very economical because there is no cost for maintenance and repair.

In addition, the real-time water level and low water measurement system using the GPS carrier of the present invention is very economical because once it is built, the satellite signal can be used free of charge, and the equipment is not made with a mechanical connection, which requires little maintenance cost.

Although the technical idea of the real-time water level and low water measurement system using the GPS carrier of the present invention has been described above with the accompanying drawings, this is illustrative of the best embodiments of the present invention and is not intended to limit the present invention. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (1)

In the real-time water level and low water measurement system using a GPS carrier to measure the water level and the low water level stored in dams, lakes, reservoirs, etc. using a plurality of GPS carriers transmitted from a plurality of GPS satellites, GPS antennas arranged in at least two or more flotation devices, each of which is fixed at a constant dam or around the water, and receiving a plurality of GPS carriers transmitted from the plurality of GPS satellites; A GPS receiver for receiving a GPS carrier received from a GPS antenna disposed at a fixed position of the dam or the surroundings and calculating a position of each GPS antenna; By using the GPS antenna position information output from the GPS receiver, the water level of each floating device is measured, the water flow is measured, and the total amount of water stored in the dam is calculated using the water information of the water. Calculation means for performing; And Real-time water level and low water measurement system using a GPS carrier, characterized in that it comprises an output means for displaying the water level and the total low water, and the flow of water output from the calculation means on the screen.