JPH01195385A - Hybrid investigation method for material buried in ground - Google Patents

Abstract

PURPOSE:To accurately discriminate a material to be investigated by radiating a pulse wave into the ground through a wide band antenna and receiving the reflected wave to subject it to signal processing and displaying the result. CONSTITUTION:The output from a buried pipe detector transmission part 9 is connected to a water meter 10 which is easily connected from the ground surface in a part of a buried pipe 11. At this time, a current 13 flows to the buried pipe 11 to generate an induction field 14. When a reception part 6 and a reception coil L of a buried pipe detector are attached to an antenna 5 of an underground investigation radar and the antenna 5 is moved, the underground investigation radar method and investigation with the buried pipe detector are simultaneously performed. Respective investigation data is sent to an underground investigation radar main body 8 through a signal cable 7. The signal generated in a transmission part 28 of an underground buried material investigation device is sent to the buried pipe 11 to generate an induction field in the vicinity of the buried pipe 11. This induction field is received by a reception coil 29 and converted to a digital value by an A/D converter 27 and stored in a main memory 21 through a CPU 23 and repeatedly displayed on a CRT 24.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an underground object exploration method for exploring underground objects.

(Prior technology) This type of underground object exploration device (hereinafter referred to as "underground exploration radar")
) is an image that represents the reflected waves of electromagnetic waves radiated into the ground that are reflected by objects with electrical properties that differ from the surrounding soil, such as buried pipes, concrete structures, and cavities. Many of the exploration images of ground-penetrating radar are generally known to display on a CRT, as shown in Figure 1(a), the underground burial situation at the measurement site as an exploration image, as shown in Figure 1(b). ing.

(Problem to be solved by the invention) However, in exploration in urban areas where burial conditions are becoming more complex and congestion is progressing, the exploration image contains various reflected waves, so it is difficult to determine which one is the exploration purpose on the image. It was very difficult to identify whether the reflected wave was a reflection wave or not.

For example, if you want to know only the water pipe 3 in Fig. 1(a),
In reality, since the buried condition is unknown, it was not possible to identify which water pipe 3 was the intended one on the image shown in FIG. 1(b).

(Means for Solving the Problems) The present invention aims to solve the drawbacks of the conventional technology, and is aimed at solving the problems of the prior art. However, it provides a ground penetrating radar that makes it possible to identify reflected waves for exploration purposes.

(Example) The present invention enables accurate identification of a target object by using a buried pipe detector in addition to measurement using a ground-penetrating radar method. Explain.

FIG. 2 is a diagram showing its configuration. In the figure, output No. 48 from the buried pipe detector transmitter 9 is connected to a water meter 10 which is a part of the buried pipe 11 and can be easily connected from the ground surface. At this time, a current 13 flows through the buried pipe 11 and an induced magnetic field 14 is generated. On the other hand, by attaching the receiver 48 part 6 and the receiving coil L of the buried pipe detector to the antenna 5 of the underground exploration radar and moving the antenna 5, exploration by the underground exploration radar method and the buried pipe detector becomes possible simultaneously. Each exploration data is sent to the underground exploration radar main body 8 through the signal cable 7.

FIG. 3 is an example of a block diagram of a ground penetrating radar system according to the present invention. This system is equipped with an interface section that can take in signals from other underground object exploration devices such as buried pipe detectors in a normal underground exploration radar system, and allows you to select each piece of surveyed data, or to send multiple data at the same time. It shall be displayed and recorded. The operation will be explained in detail below.

A very narrow pulse signal from the transmitter 16 is radiated into the ground from the broadband transmitting antenna 15, hits the buried pipe 11, is reflected, and is received by the receiving antenna 17. The low frequency received signal is converted into a low frequency signal by the sampler in the receiving section 18 and amplified, and then converted into a digital value by the A/D converter 20, and is stored in the main memory 21 via the CPU 23.

The signals stored in the main memory 21 undergo coordinate transformation by the CPU 23, are rewritten into signals for display on the CRT 24, are stored in the sub memory 22, and are repeatedly displayed on the CRT 24.

This is the operation of a normal underground exploration radar system.

On the other hand, the signal generated by the sending ε unit 28 of the underground object exploration device is sent to the buried pipe 11, and generates an induced magnetic field near the buried pipe 11. This induced magnetic field is received by the receiving coil 29, amplified by the receiving section 25, converted to a digital value by the A/D converter 27 via the interface section 26 at an appropriate timing, and stored in the main memory 21 via the CPU 23. . After that, the information is repeatedly displayed on the CRT 24 in exactly the same manner as in a normal underground exploration radar system.

FIG. 4 is a display example of an exploration image according to the present invention. In this display example, exploration images 41a and 42a using the ground-penetrating radar method
, 43a, and 44a, the changes in the exploration data 45a of the buried pipe detector are also displayed at the bottom of the screen.

Therefore, among the reflected waves of buried objects included in the exploration image of the ground-penetrating radar method, those whose horizontal direction coincides with the position of the buried pipe according to the output result of the buried pipe detector 4
By selecting 3a, it is possible to distinguish the reflected wave from the buried pipe targeted for exploration from others. Similarly, if a device that detects cavities is used instead of a buried pipe detector, it is possible to identify reflected waves from a cavity from among a large number of reflected waves.

(Effects of the Invention) As explained above, by combining the underground exploration seeder method with other underground buried object exploration devices, even when the exploration results include reflected waves from various buried objects,
Since the reflected waves for exploration purposes can be distinguished from other reflected waves, there is an advantage that accurate and rapid exploration is possible.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are examples of conventional underground radar exploration images, Figure 2 is a configuration diagram showing an embodiment of the present invention, Figure 3 is a block diagram of the present invention, and Figure 4. (a) and (b) are display examples of exploration images of the present invention. 5... Underground exploration radar antenna, 6... Buried pipe detector receiving section, 7... Signal cable, 8... Underground exploration radar body, 9... Buried pipe detector transmitting section, 10 ... Water meter, 11 ... Buried pipe, 12 ... Earth, 13Φ.
φ current, 14... Magnetic field, L... Receiving coil, 15.
...Transmission antenna, 16.28...Transmission section, 17...
・Receiving antenna, 18.25...Receiving section, 19...
Control unit, 20.27... AD converter, 21...
Main memory, 22... Secondary memory, 23... CPU12
4...CPU124...ψ interface section. Patent applicant Japan Radio Co., Ltd.

Claims (1)

[Claims] Buried equipment that emits pulse waves with an extremely short pulse width into the ground through a wideband antenna, receives reflected waves from underground objects, cavities, strata, etc., processes the signals, and displays them. A hybrid underground object exploration method characterized in that detection information from an object exploration device and detection information from a buried pipe detector are displayed overlappingly.