JPH05150041A - Buried object probing device - Google Patents

Abstract

PURPOSE:To perform gradation corresponding to an application and a buried object by storing plural gradation conversion curves previously, and selecting one of the stored gradation conversion curves according to a reflection signal to perform gradation. CONSTITUTION:Beams are radiated toward a structure from an antenna 2 through a transmitting circuit 1 to scan the structure, and its reflection is received by a receiving antenna 3 and inputted into an A/D converter 5 through a receiving circuit 4. Conversion into a digital signal is performed at a converter 5, and this signal is inputted into a gradation converter 6, where gradation corresponding to the intensity of the signal is performed. At the time of performing this gradation, the gradation difference is made large at the weak part of the reflection signal and easy at the strong part of the signal by a ROM table 11 previously stored with plural gradation conversion curves. Accordingly, even in the case of various buried objects being buried in the complicated position relation, the existence thereof can be displayed clearly on a CRT 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buried object exploration apparatus for visualizing buried objects in the ground or concrete structures.

[0002]

2. Description of the Related Art A conventional device of this type is, for example, the device shown in the block diagram of FIG. FIG. 3 shows that a pulsed electromagnetic wave having a very narrow width is transmitted, for example, while scanning an antenna (hereinafter, this is referred to as beam scanning), and a reflected wave from a buried object in the ground or a concrete structure is received and buried. It is a block diagram which shows the outline of a structure of the buried object search radar which image | photographs an object with a video. In the figure, 1 is a transmitting circuit, 2 is a transmitting antenna, 3 is a receiving antenna, 4 is a receiving circuit, 5 is an A / D converter, 6a is a gradation converter, 7 is a display memory, and 8 is a display memory.
Is a D / A converter, 9 is a display controller, and 10 is a display device (CRT).

Next, the operation of the apparatus shown in FIG. 3 will be described. The beam is scanned from the transmitting antenna 2 toward the ground or a concrete structure via the transmitting circuit 1, the reflection from the buried object is received by the receiving antenna 3, and is input to the A / D converter 5 via the receiving circuit 4. Then, it is converted into a digital signal by the A / D converter 5 and this digital signal is input to the gradation converter 6a. The gradation converter 6a performs gradation according to the intensity of the signal (in the case of a black-and-white image, brightness gradation is applied), which is temporarily stored in the display memory 7, and a speed suitable for display is displayed. Is read out and converted into an analog signal by the D / A converter 8 and displayed as an image on the CRT 10. The display controller 9 controls gradation and reading speed.

FIG. 4 is a diagram for explaining the gradation setting performed by the gradation converter 6a.
As shown at 20 in FIG. (A), it is simply replaced with each gradation that is proportional to the intensity of the reflected signal, or a simple output conversion circuit (not shown) is provided, and for example, when the reflected signal is weak. Indicates gradation along the proportional line indicated by reference numeral 21 in FIG. (B), and when the reflected signal is strong, the output value of the output conversion circuit is switched to indicate the level along the proportional line indicated by reference numeral 22 in FIG. It is structured to perform choreography.

[0005]

Since the conventional buried object exploration apparatus as described above performs gradation in proportion to the intensity of the reflected signal as described above, for example, a buried object at a shallow position and a deep object can be deepened. There is a problem in that it is not possible to depict a very strong reflection signal and a weak reflection signal in a mixed manner such that the buried object at a position is projected on the same display screen.

FIG. 5 (A) is an example of an embedded object displayed on the CRT 10, and FIG. 5 (B) is a diagram showing a reflection signal of the MM 'cross section, and each part constituting the embedded object. When there is no great difference in the intensity of the reflected signal at, the tone conversion along the proportional line 21 is performed in order to clarify the tone of the portion where the reflected signal is weak, as shown in FIG. All the strong signal parts have the same gradation (“white” in this example). On the contrary, when gradation conversion along the proportional line 22 is performed in order to clarify the gradation of the portion where the reflected signal is strong, FIG.
As shown in (D), all the weak portions of the signal have the same gradation (“black” in this example), and the embedded object cannot be recognized in any case.

[0007] This means that the intensity of the signal is given an accurate gradation, which is not a problem in a general image rendering apparatus, but the buried object exploration apparatus does not reflect a strong reflection from a strong reflecting object. The main purpose is to display the existence of all the buried objects up to the buried objects of (1) and to recognize what each buried object is. Therefore, even the weakly reflected buried objects are displayed without omission, and Gradation must be possible without saturation even with a reflection signal from a strongly reflecting buried object.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a buried object exploration apparatus capable of performing gradation according to the purpose of the apparatus.

[0009]

A buried object exploration apparatus according to the present invention stores a plurality of gradation conversion curves in advance,
One of the gradation conversion curves stored according to the reflection signal is selected to perform gradation.

[0010]

The gradation conversion curve to be stored in advance may include a curve that is not proportional to the intensity of the reflected signal, and optimal gradation can be performed according to the reflected signal.

[0011]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 3 denote the same or corresponding parts,
Reference numeral 6 is a gradation converter in the present embodiment, and 11 is a ROM table in which a plurality of gradation conversion curves are stored in advance.

FIG. 2 shows an example of a gradation conversion curve stored in advance in the ROM table 11. Like the curve 23 in FIG. 2, a large gradation difference is provided in a portion where the reflected signal is weak,
By making the gradation difference slow in the portion where the reflection signal is strong, it becomes possible to clearly display the presence of each buried object even when various buried objects are buried in a complicated positional relationship. In addition to the gradation conversion curve 23 shown in FIG. 2, the ROM table 11 has gradation conversion curves 20 to 2 shown in FIG.
It goes without saying that 2 etc. is stored.

Embodiment 2. Next, selection of the gradation conversion curve will be described. Which of the gradation conversion curves is selected may be manually switched, for example, while watching the image once projected on the CRT 10, but the gradation converter 6 detects the intensity of the reflection signal and One gradation conversion curve is automatically selected based on the average value of the signal. For example, one gradation conversion curve is automatically selected on the basis of the reflection signal of the highest output. For example, one gradation conversion curve is automatically selected based on the reflected signal of the lowest output among the signals that have reacted. It is also possible to use a device that allows automatic selection such as.

In the above-mentioned embodiment, the gradation according to the brightness difference of the black-and-white image is explained, but the same can be applied to the apparatus for gradation using the R, G and B color signals. .

Further, although the above-mentioned embodiment has been described by using the buried object search radar, it is needless to say that the present invention can be applied to all buried object search devices for gradationally marking the buried object and displaying it in a video image.

[0016]

As described above, the buried object exploring apparatus of the present invention can be displayed with a clear gradation difference in both the portion where the reflected signal is strong and the portion where the reflected signal is weak. There is an effect that gradation can be applied according to

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a gradation conversion curve stored in a gradation converter of the present invention.

FIG. 3 is a block diagram showing a conventional device of this type.

FIG. 4 is a diagram for explaining gradation formation in a conventional device.

FIG. 5 is a diagram showing a drawback of the conventional device.

[Explanation of symbols]

 1 transmitting circuit 2 transmitting antenna 3 receiving antenna 4 receiving circuit 5 A / D converter 6 gradation converter 7 display memory 8 D / A converter 9 display controller 10 CRT 11 ROM table 23 gradation conversion curve

Claims (2)

[Claims] 1. An embedded object exploration device for converting a reflection signal from an embedded object into a signal representing each gradation by a gradation converter and displaying the embedded object as an image having a gradation difference on a display device, The gradation converter includes a plurality of gradation conversion curves that select gradation steps that are not proportional to the strength of the reflected signal, and gradation conversion curves that select gradation steps that are not proportional to the strength of the reflected signal. The gradation conversion curve is stored in advance, one of the stored gradation conversion curves is selected according to the reflection signal, and a means for performing gradation conversion using this gradation conversion curve is provided. Characteristic buried object exploration device. 2. The buried object exploration device according to claim 1, wherein the gradation conversion curve is selected automatically based on an average value or a maximum value or a minimum value of the reflection signal. .