JPH0236384A - Distance measurement method between transmission line tower support points - Google Patents

Abstract

PURPOSE:To shorten a movement time by fitting antennas for radio wave reception at basic points between the support points of steel towers, receiving a signal sent from an artificial satellite by the antennas, and analyzing the phase difference of the received wave and finding the distance between the support points. CONSTITUTION:The time signal radio wave 11 sent from the artificial satellite 10 is received by antennas 3 and 3' installed at points P and Q. The radio wave 11 has an equiphase wave surface having an equal-distance radius based upon the satellite 10 as the center and the equiphase wave surface passing the point P and the equiphase wave surface passing the point Q are different. Therefore, there is a delay time DELTAt of the arrival of the radio wave at the point P as compared with the point Q and this appears as the phase difference of the received radio wave. This received phase data is inputted to, for example, a floppy disk and processed on an off-line basis to find the distance S.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distance measuring method for measuring the distance between tower support points of a power transmission line with extremely high precision using simple means.

[Prior Art] In the prefabricated overhead line construction method, it is necessary to measure the distance between tower support points where power transmission lines are attached with high accuracy of at least 1/10,000 or more.

To this end, several precision ranging methods have been proposed, including trigonometry.

FIGS. 4 and 5 illustrate the two-point ground angle measurement method, which is the second of such precision surveying methods. In this method, as shown in Fig. 5, reflectors 2゜2゛ are installed at the measurement reference points X and Y of the span length S of the steel towers 1 and 1-, and the transit is set at an appropriate distance MD3 above the ground. T1. At the same time, a light wave range finder Sz is installed at a distance ill D t from transit TI, and Fm is installed from transit T2.
Besides Jiff D 2, it also uses light wave ranging (ik S
2 is installed, and the required angles are measured with high precision by Transit TI and T2, while light wave ranging asx and S
By z, the distance L to the reflector 2.2- shown in the figure, respectively.
t.

L2 is measured with high precision, and the span length S and height difference H are determined with high precision using calculation formulas described later.

This method involves work on the tower, making it difficult to conduct live line surveys. However, it is possible to measure even if the measurement points are narrow, the measurement error is small, and measurements can be taken in a short time compared to other methods. Because of this advantage, it is widely used in prefabricated overhead lines for newly constructed lines.

The present measurement method will be explained below with reference to FIGS. 4 and 5.

As mentioned above, Transit TI, T2 and light wave ranging @
s1. After installing sz, measure the distance DID2 and Ds with high precision, and set the angle αl.

α2. αs, A1. Measure Az and use the following formula to calculate the distance 11
and find J2.

tH=D1 (cosjIcosαIcos(Hα+−
H+ l+5inA1 sinα8)b ”J)! (
coi Ax cot lft cas (H(h-H
t l + 5la7i sla d, to find the length of 1 span S, add 71. calculated from the above equations (1) and (2) to the following equation (3). Just substitute J12.

S-(jlcos72sin(H4-ffl)-llc
os, 41sin(#1-Hα,))2 Also, the height difference H
can be determined by the following equation (4).

#=lzsinAz+As1a4 4sinjl [Problem to be Solved by the Invention] According to the above measurement method, high precision measurement of about 0.5/10.000 is possible, but the constraint of measurement in visual field cannot be avoided. , there are the following problems.

(1) It is necessary to select a place where the object can be standardized;
When trying to select such a location in a mountainous area, the location is often off the road and requires a lot of time to travel.

(2) If the site conditions are poor and visibility is insufficient, it will be necessary to cut down trees in a 5-10 meter width along the reference line to ensure the standards, which will lead to the destruction of nature.

(3) Due to the need to standardize the target object, measurement is not possible under conditions such as rain, snow, or fog. Therefore, in mountainous areas, etc., measurements are likely to be hampered by these types of weather conditions, and the number of days for measurements tends to be much longer than planned.

(4) Work hours are limited to daytime hours with good visibility.

(5)! Since there are many fixed points, measurement errors tend to accumulate, and it is impossible to further improve the accuracy beyond the above-mentioned 0.5/10.000.

The purpose of the present invention is to solve the problems of the prior art as described above, and to measure the span length with extremely high accuracy regardless of day or night, without being restricted by weather conditions or visual conditions. The aim is to provide a new measurement method that can

[Means for Solving the Problems] The present invention provides an antenna for radio wave reception that is installed at a base point between the support points of a steel tower, receives a signal transmitted from an artificial satellite by the antenna, and transmits the received wave at each tower. This method analyzes the phase difference between the support points and determines the large separation between the supporting points.

[Effect 1: Since the steel tower is built high above the ground, there is no obstacle to the radio waves from the artificial satellite, and the artificial satellite is transmitting the zero time signal that can accurately receive the radio waves being transmitted. Many satellites have already been launched, and a system has been established in which reception is possible from any one of the satellites 24 hours a day, so as long as the measuring equipment is installed on the tower, it can be used day or night and regardless of weather conditions. , it becomes possible to perform highly accurate measurements, and the number of days required for measurements can be significantly shortened.

[Example] The present invention will be described below with reference to Examples.

FIG. 1 is an explanatory diagram showing how the span length S between steel towers 1° and 1' is measured by the measuring method according to the present invention.

Respective base points X and Y of measurement span S of steel towers 1 and 1-
A receiving antenna 3.3- is installed at the point and receives time signal radio waves 11 from the artificial satellite 10 shown in FIG.

At present, a large number of artificial satellites 10 for the artificial satellite positioning system are already orbiting the earth, and a system has been established in which signals from any one of the artificial satellites can be received for 24 hours in most areas of the earth.

The artificial satellite 10 is equipped with an atomic clock, and the artificial satellite 10 transmits extremely accurate time signals at frequencies of approximately 1.2 GHz and approximately 1.5 GHz.
The system is open to the private sector and can be freely received anywhere on Earth.

FIG. 2 is an explanatory diagram showing a specific example of receiving the time signal radio wave 11 transmitted from such an artificial satellite 10 and measuring the distance S between point P and point Q.

Antennas 3 and 3- are installed at points P and Q, respectively, and the phase angles of radio waves are measured with respect to the clocks at points P and Q. In wave 11, as shown in Figure 2, artificial satellite 1
There is a phase plane at an equidistant radius centered on 0,
The same phase plane passing through point P and the same phase plane passing through point Q are different as shown in the figure. A delay time Δt occurs in the arrival of the radio wave 11 at point P with respect to point Q, and this becomes a phase difference between the received radio waves.

If the phase data received by points P and Q are input to a floppy disk, for example, and the calculations are processed offline,
The distance s can be determined from the phase difference.

The same means as described above may be used to determine the span length S between the steel towers 1.1 and 1 shown in FIG.

As mentioned above, the antenna 3. is attached to the base points X and Y of the steel tower 1.
3" is installed, and the receiving device 5, is connected via the lead wire 4.4".
In the diagram, 7° 7- is a power supply connected to 5-. The received data of the time signal radio waves 11 received at points X and Y in this manner is processed by the personal computer 6.6- and recorded on a floppy disk. By performing calculation processing on this floppy disk off-line, the span length S can be determined from the phase difference of the radio waves as described above.

When determining the height difference between points X and Y, the software for calculation processing may be rearranged.

In the above, in order to ensure more accuracy, it is desirable to receive radio waves from two artificial satellites at the same time, rather than just receiving signals from one artificial satellite. Considering the reception of radio waves, an omnidirectional antenna is most preferable, but if multipath is observed due to reflections from steel towers, a directional antenna equipped with an artificial satellite tracking device may be used.

In order to avoid this multipath problem, auxiliary rods 8, 8- are installed as shown in FIG.
゛ may be attached.

Furthermore, since the radio waves transmitted from the satellite to the earth penetrate the ionosphere and reach the ground, there is an error in arrival time, which can cause ranging errors. As a countermeasure to this, it is possible to insert a correction circuit and eliminate the error factor.

When measuring the tower span length as described above, the measurement error is actually 1/1,000,000, which dramatically improves the accuracy compared to the conventional method described above. It can be expected to be of great benefit in the construction of UHV power transmission lines, etc.

In addition, an optical fiber composite overhead ground wire (OPGW) was installed on the tower to be measured.
), the received signal is sent to the relevant 0P.
It is also possible to use the GW to send the data to a central control center, where the data can be processed by a computer. This method is useful not only for measuring distances between towers, but also for tracking the degree of inclination of towers.

[Effects of the Invention] As described above, the present invention can provide excellent effects such as those described above.

(1) Since the measuring equipment can be installed near the steel tower and the access road to the tower is usually open, the travel time for measurement can be greatly shortened compared to the conventional example.

(2) There is no need to ensure visibility and there is no need to cut down trees in mountainous areas, so nature conservation can be achieved.

(3) Measurements can be made without being affected by weather conditions such as rain, snow, or fog, and the number of work days required for measurement can be greatly reduced.

(4) It is also possible to install the antenna during the day and perform measurements at night, so there is no restriction on the time of measurement.

(5) The measurement error can be improved by two orders of magnitude compared to the conventional method, and extremely highly accurate measurement can be achieved.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing how distance is measured by the method according to the present invention, Figure 2 is an explanatory diagram showing the principle of determining distance wlpJ using an artificial satellite, and Figure 3 is an illustration of installing the antenna using an auxiliary rod. FIG. 4 is an explanatory diagram showing the calculation formula in the conventional method, and FIG. 5 is an explanatory diagram showing the conventional measuring method. i, t-: steel tower, 3.3-: antenna, 4.4-: lead wire, 5.5°: receiving device, 6.6-: personal computer, 10: artificial satellite, 11: wave.

Claims (1)

[Claims] (1) Install a radio wave receiving antenna at the base point between the support points of the steel tower, receive the signal transmitted from the artificial satellite with the antenna, analyze the phase difference of the received waves at each tower, and measure the distance between the support points. A distance measurement method between transmission line tower support points to find the distance.