JP2000329859A - Investigation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an investigation device capable of acquiring and displaying a reflected signal from near or far object without saturating it, without using a circuit for generating an STC (sensitivity time control) signal nor a variable amplification device for changing an amplification factor by the STC signal. SOLUTION: This investigation device comprises; a transmission antenna 22 for radiating an electromagnetic wave into the ground; a reception antenna 23 for receiving a reflected electromagnetic wave from a buried object in the ground; one or more amplification devices 24, 25, 26 for amplifying a received signal with different magnifications; two or more recording devices 27, 28, 29 for memorizing amplified signals; a control device 30 for selecting either corresponding to the signals memorized by the two or more recording devices 27, 28, 29; and an indicator 31 for displaying a selected signal. Therefore, a reflected signal from a near or far object B can be acquired and displayed without being saturated, and an STC circuit can be omitted, to compose a circuit inexpensively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a search device, and more particularly to a search device for detecting a reflected wave from a buried object or the like in a concealing portion.

[0002]

2. Description of the Related Art Generally, in a radar, a reflected signal from a nearby object is detected earlier in time and large in intensity. On the other hand, a reflected signal from a distant object is detected late in time and small in intensity. For this reason, in order to simultaneously detect signals from near and far, STC (Sensitivity Time Control)
l) There is a technology. In the STC, the amplification factor is reduced when the target is nearby, that is, when the time is early, and the amplification factor is increased for a signal that is distant, that is, a signal that is late in the time. Can be detected.

FIG. 4 is a block diagram showing a configuration according to a conventional example. According to this conventional example, the signal generation circuit 10 generates a promise signal. The signal is transmitted from the signal generation circuit 10 to the transmission antenna 11, and the transmission antenna 11 transmits an electromagnetic wave underground. Electromagnetic waves are reflected by the buried object B underground,
The reflected electromagnetic wave is received by the receiving antenna 12. Next, the received signal is amplified by the variable amplifier 13. This variable amplifier 13 has a gain control function,
The STC signal generated by the STC signal generator 15 is added as the gain control signal. Thereby, when it is for a nearby object, that is, when the time is early, the amplification factor is reduced, and when it is for a distant object, that is,
When time is late, increase the amplification factor.

FIG. 5 is a diagram showing the signal magnitude and the amplification factor of the variable amplifying device 13 in the conventional example. FIG. 5A is a diagram illustrating a relationship between a time when a reflected electromagnetic wave from a target is received and a magnitude of a received signal. For nearby objects,
The received signal is large (100 mV at 10 ns), and small for a distant object (1 m at 30 ns).
v). FIG. 5B is a diagram illustrating a relationship between time and an amplification factor of the variable amplifier 13. The variable amplifier 13 has an STC
When the STC signal is input from the signal generator 15 and the distance is short, the amplification factor is reduced (× 10 at 10 ns), and the distance is increased (× 100 at 30 ns).
0). FIG. 5C is a diagram illustrating a relationship between time and the magnitude of a signal input to the recording device 14. At each time,
This shows that the same input voltage of 1000 mV is input. The result is stored in the recording device 14 and displayed on the display 16. Since the magnitude of the STC signal is known, the magnitude of the signal stored in the recording device 14 is similar to that of the near case (1000 mV ÷ 10 = 100 m at 10 ns).
V), when it is far (1000 mV ÷ 100 at 30 ns)
(0 = 1 mV) of the received signal.
As one example of the prior art, Japanese Patent Application Laid-Open No. 58-780 discloses a pulse radar receiver which switches several types of fixed STC signals in accordance with radar use conditions and adds the same to an amplifier as a gain control signal.

[0005]

However, in the prior art, a circuit for generating an STC signal and a variable amplifying device for greatly changing the amplification factor in a short time by the STC signal are required, so that the circuit configuration is complicated. There is a problem that it becomes large and expensive. In view of the above problems, the present invention obtains reflected signals from nearby and distant objects without saturating without using a circuit for generating an STC signal or a variable amplifying device that changes the amplification factor by the STC signal. It is an object of the present invention to provide a search device capable of displaying.

[0006]

A probe according to the present invention comprises a transmitter for emitting a wave, a receiver for receiving a reflected wave from an object, and amplifying a signal received from the receiver at different magnifications. One or more amplifying devices, two or more recording devices for storing amplified signals from the amplifying devices, and a storage signal of any one of the recording devices according to the stored signals stored in the two or more recording devices. The control device includes a control device to be selected and a display device that displays a selection signal selected by the control device.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
FIG. 1 is a block diagram showing a configuration of a search device according to a first embodiment of the present invention. The exploration apparatus according to the present embodiment uses a promise signal (impulse, monocycle, M-sequence modulation code, etc.)
, A transmitting antenna 22 for radiating electromagnetic waves into the ground, a receiving antenna 23 for receiving a reflected signal from an underground object B, and two or more amplifying the received signal at different magnifications Amplifying devices, that is, amplifying devices 1, 24, amplifying devices 2, 25,.
6, and two or more recording devices for storing the amplified signal, that is, a first recording device 27, a second recording device 28,.
‥, an n-th recording device 29, and a control device 30 for selecting one according to signals stored in the two or more recording devices
And a display 31 for displaying a selection signal.

According to this device, the signal generation circuit 21 generates a promise signal (impulse, monocycle, M-sequence modulation code, etc.). An electromagnetic wave is transmitted from the transmitting antenna 22 underground. The electromagnetic wave is reflected by the underground object B, and the electromagnetic wave reflected by the receiving antenna 23 is received, and the received signal is used as an electrical reception signal. The received signals are amplified by the amplification devices 1 and 2
4, amplifying devices 2, 25,..., Amplifying devices n and 26, and a first recording device 2 corresponding to each amplifying device
7, and stored in the second recording device 28,.

FIG. 3 shows amplifying devices 1, 24, amplifying devices 2,
25, ‥‥‥, amplifying devices n and 26, and first recording device 2
7 is a diagram illustrating the magnitude of a storage signal for each combination with the second recording device 28,..., And the n-th recording device 29. The control device 30 generates a display signal from a signal that is effective and can be estimated to have the highest resolution based on the intensity of the plurality of stored signals. For example, it is assumed that the maximum input range of the first recording device 27, the second recording device 28,..., And the n-th recording device 29 is 1V. The size of the received signal is 10
100mV after ns, 10mV after 20ns, 30ns
Later, it was 1 mV, and the first amplification / recording was × 10 (FIG. 3).
(A)), the second amplification / recording was × 100 (FIG. 3 (B)),
It is assumed that the third amplification / recording has an amplification factor of × 1000 (FIG. 3C). In this case, if attention is paid after 10 ns, since the second amplification / recording and the third amplification / recording are both saturated, only the first amplification / recording can be used linearly without being saturated. The control device 30 selects the first amplification / recording and converts the reception voltage from this value (1000 mV) (1000 mV ÷ 10 = 100 m).
V). After 20 ns, the first amplification / recording and the second amplification /
Although the recording can be used linearly without saturation, the second amplification
Since the recording stores a larger signal (1000 mV), the resolution is better, the second amplification / recording is selected, and the received voltage is converted from this value (1000 mV) (1000 mV).
V ÷ 100 = 10 mV). Similarly, after 30 ns, the third amplification / recording is selected. These results are displayed on the display 31.

FIG. 2 is a block diagram showing a configuration of a search device according to a second embodiment of the present invention. The exploration device of the present embodiment is different from the first embodiment in that the first recording device 2
The amplification device corresponding to 7 is omitted. According to this device, the signal generation circuit 21 generates a promise signal (impulse, monocycle, M-sequence modulation code, etc.). An electromagnetic wave is transmitted from the transmitting antenna 22 underground. The electromagnetic wave is reflected by the underground object B, and the electromagnetic wave reflected by the receiving antenna 23 is received, and the received signal is used as an electrical reception signal. First
The recording device 27 stores the received signal from the receiving antenna 23 as it is. This is because a reflected signal from a nearby object is detected early in time and large in intensity, and may be used as it is.
In the amplifying device corresponding to another recording device, the received signal is amplified by the amplifying devices 2, 25,..., And the amplifying devices n and 26 at different magnifications (different from the magnification × 1 when no amplification is performed). The information is stored in the second recording device 28,..., N-th recording device 29 corresponding to each amplifying device.

In operation, similarly to the first embodiment, the control device 30 generates a display signal from a signal which can be estimated to be effective and has the highest resolution from the strengths of a plurality of stored signals. . According to this embodiment, a signal having a large intensity is not amplified by using the amplifier, so that the amplifier is not necessary, and the device can be manufactured more inexpensively and easily.

The present invention is not limited to the above embodiment. In the second embodiment, one amplifier 1, 25 is used with n = 2, and the amplifiers 1, 25
May be different from 1. In claim 1 including this case, "one or more amplifying devices that amplify at different magnifications" is described. In addition, an ultrasonic wave may be used instead of an electromagnetic wave, and a search device using an ultrasonic wave may be used.
In this case, an ultrasonic transmitter and an ultrasonic receiver are used instead of the antenna. Further, the object to be searched is not limited to a buried object, and any object such as a fish school in the sea or a built-in body can be used as long as the object is searched by a wave. Further, the transmitting antenna and the receiving antenna can be shared. An ultrasonic transmitter and an ultrasonic receiver can also be used.

[0013]

According to the present invention, the circuit for generating the STC signal and the variable amplifying device for changing the amplification factor by the STC signal are omitted, and the reflected signals from the near and far objects are not saturated. Can be obtained and displayed, and a circuit can be configured at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a search device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a search device according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating the magnitude of a storage signal for each combination of an amplification device and a recording device according to the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional search device.

FIG. 5 is a diagram illustrating a signal magnitude and an amplification factor of a variable amplifying device according to a conventional example.

[Explanation of symbols]

 Reference Signs List 21 signal generation circuit 22 transmitting antenna (transmitter) 23 receiving antenna (receiver) 24, 25, 26 amplifying device 27, 28, 29 recording device 30 control device 31 display device (display device) B buried object (object)

Claims (1)

[Claims] A transmitter for emitting a wave; a receiver for receiving a reflected wave from an object; one or more amplifying devices for amplifying a signal received from the receiver at different magnifications; and the amplifying device. Two or more recording devices for storing the amplified signals from the plurality of recording devices, a control device for selecting a storage signal of any one of the recording devices in accordance with the storage signals stored in the two or more recording devices, And a display device for displaying the selected signal.