JPH0549197B2 - - Google Patents

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 buried object exploration device (hereinafter referred to as "underground exploration radar") uses electromagnetic waves radiated underground to detect the electrical properties of surrounding soil such as buried pipes, concrete structures, cavities, etc. This image shows the reflected waves reflected by different objects. Exploration images of ground-penetrating radar usually show the underground burial situation at the measurement site as shown in Figure 1a, as an exploration image as shown in Figure 1b.
Many CRT display devices are known.

(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 Figure 1a, it is impossible to identify which water pipe 3 you are looking for on the image in Figure 1b because the actual burial situation is unknown. Ta.

The present invention aims to eliminate such drawbacks of the conventional technology, and is capable of identifying reflected waves for exploration purposes even when images include reflected waves from buried objects other than the exploration target. The purpose of the present invention is to provide an underground exploration radar that enables

(Means for Solving the Problems) That is, the present invention radiates a pulse wave having an extremely short pulse width into the ground through a wideband transmitting antenna mounted on a mobile underground exploration radar antenna device, and The pulse wave is transmitted to the broadband receiving antenna mounted on the antenna device of the
In an underground exploration radar system that receives reflected waves reflected by cavities and strata, processes the signals, and displays detection information, the mobile antenna device includes a receiving coil of an electromagnetic induction type buried pipe detector. , the receiving coil receives the induced magnetic field from the buried pipe generated by the buried pipe detector, and the detection information obtained by signal processing is displayed overlappingly with the detection information by the underground exploration radar system. It is characterized by:

(Example) The present invention makes it possible to accurately identify 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, the output signal 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 receiving section 6 and 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
A normal underground exploration radar system is equipped with an interface section that can receive signals from other underground object exploration devices such as buried pipe detectors, and each piece of surveyed data can be selected or multiple data can be displayed and recorded at the same time. It is something to do. The operation will be explained in detail below.

A very narrow pulse signal from the transmitter 16 is radiated underground from the wideband transmitting antenna 15.
It hits the buried pipe 11 and is reflected, and the reception antenna 17
received at The low frequency received signal is converted into a low frequency signal by a sampler in the receiving section 18 and amplified, and then converted into a digital value by an A/D converter 20 and stored in the main memory 21 via the CPU 23. The signal stored in the main memory 21 is sent to the CPU 23
The coordinates are exchanged by , and the signal is rewritten to the CRT 24 display signal, stored in the sub memory 22, and repeated.
Displayed on CRT24. This is the operation of a normal underground exploration radar system.

On the other hand, the signal generated by the transmitter 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, passed through the interface section 26, converted into a digital value by the A/D converter 27 at an appropriate timing, and stored in the main memory 21 via the CPU 23. Ru. After that, the information is displayed repeatedly 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, in addition to exploration images 41a, 42a, 43a, and 44a using the underground exploration radar, changes in exploration data 45a from the buried pipe detector are also displayed at the bottom of the screen.

Therefore, among the reflected waves of the buried object included in the exploration image of the ground penetrating radar method, the wave 43a whose horizontal direction coincides with the position of the buried pipe according to the output result of the buried pipe detector is selected. By doing so, it is possible to distinguish the reflected waves from the buried pipes for exploration purposes. Similarly, if a cavity detection device is used instead of a buried pipe detector, a cavity reflected wave can be identified from a large number of reflected waves.

(Effects of the Invention) As explained above, by combining the ground-penetrating radar method with other underground buried object detection 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]

1a and 1b are examples of conventional underground radar exploration images, and FIG. 2 is a configuration diagram showing an embodiment of the present invention.
FIG. 3 is a block diagram of the present invention, and FIGS. 4a and 4b 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 main body, 9... Buried pipe detector transmitting section, 1
0... Water meter, 11... Buried pipe, 12... Earth, 13... Current, 14... Magnetic field, L... Receiving coil, 15... Transmitting antenna, 16, 28... Transmitting section, 17... ...Receiving antenna, 18, 25...Receiving unit, 19...Control unit, 20, 27...AD converter, 21...Main memory, 22...Sub memory,
23...CPU, 24...CRT, 26...Interface section.

Claims (1)

[Claims] 1 A pulse wave having an extremely short pulse width is radiated into the ground through a wideband transmitting antenna mounted on a mobile ground-penetrating radar antenna device, and the pulse wave is radiated into the ground by a wideband receiving antenna mounted on the mobile antenna device. In a ground penetrating radar system that receives reflected waves reflected by buried objects, cavities, strata, etc., processes the signals, and displays detection information, the mobile antenna device is equipped with an electromagnetic induction type buried pipe. Equipped with a receiving coil of a detector, the receiving coil receives the induced magnetic field from the buried pipe generated by the buried pipe detector, and the detection information obtained by signal processing is transmitted to the detection information by the underground exploration radar system. A hybrid underground object exploration method characterized by displaying overlapped images.