JPS5872074A - Display method for side lobe suppression - Google Patents

Abstract

PURPOSE:To prevent the degradation of a display image due to the side lobe to display a high dynamic range image, by obtaining side lobe values corresponding to a changing reflection signal strength to eliminate the side lobe. CONSTITUTION:Pulse-modulated radio or acoustic waves are transmitted by an antenna, a wave transmitter or the like, and reflected waves from a prescribed target are received by a sensor array 1, and the signal strength in each direction of incidence angle is detected by a beam synthesizing circuit 2. One- sector components of signal strength are stored in a memory circuit 9, and a maximum value of signal strength stored in the memory circuit 9 is detected by a maximum value detecting circuit 10. The maximum value detected in this manner is used as a main lobe value, and a side lobe value is obtained in a side lobe operating circuit 11; and when each signal strength and the side lobe value are compared with each other to discriminate the side lobe in a side lobe discriminating circuit 4, its signal strength is eliminated. The output value of the side lobe discriminating circuit 4 is amplified by a video amplifying circuit 5 and is supplied as a luminance signal to a display device 6.

Description

[Detailed Description of the Invention] The present invention suppresses side ropes of radar, sonar, etc.
The present invention relates to a method for displaying high dynamic range images.

Conventionally, in this type of display method, in order to suppress side ropes, the side ropes were set to be below a predetermined threshold level and deleted.

In such a processing method, a small main lobe signal below an originally effective threshold value is deleted, resulting in a degraded image. Therefore, when the threshold level is lowered to make the most of small signals, there are a number of drawbacks such as side ropes being displayed.

Figure 1 shows a circuit diagram implementing a conventional sidelobe suppression display method. That is, in FIG. 1, 1 is a sensor array, 2 is a beam combining circuit, 3 is a sidelobe value setter, 4 is a sidelobe discrimination circuit, 5 is a video amplifier circuit, 6 is a display, and 7 is an X-axis side direction. Amplifier circuit quantity Ka line and 8 are Ka lines for the Y-axis side amplifier circuit.

The conventional sidelobe suppression display method in a circuit configured as described above first transmits pulse-modulated radio waves or sound waves using an antenna, a transmitter 1, etc., and then receives reflected waves from a predetermined target using a sensor array 1. The beam combining circuit 2 detects the signal strength in each incident angle direction. Next, the sidelobe discrimination circuit 4 compares each signal strength with the sidelobe value set by the sidelobe value setter 3 to determine whether it is a sidelobe, and when it is determined that it is a sidelobe, changes the signal strength. delete. Then, the output value of the sidelobe discrimination circuit 4 is amplified by the video amplifier circuit 5,
This is the luminance signal of the display 6. In this case, the brightness position of the display 6 is determined by supplying the outputs of the X-axis lateral amplifier circuit and the Y-axis lateral amplifier circuit to the display 6 via output lines 7.8, respectively.

In this way, according to the conventional circuit system, the sidelobe value is constant, so in order to suppress the sidelobe, it is necessary to suppress the sidelobe by adjusting the mainlobe value as shown by the characteristic line ■ in Figure 2. ] The sidelobe value must be 7'1 as shown by the -1 characteristic line ■. In this case, everything below the main lobe signal ←'' and the side lobe value (characteristic line ■) is deleted, resulting in an extremely unsatisfactory image. Therefore, if the sidelobe value is lowered evenly, sidelobes will occur where the mainlobe signal is strong, resulting in the disadvantage that a degraded image will not be visible.

Therefore, the present invention has been proposed to overcome the problems of the conventional sidelobe suppressed display method described above.
The purpose of this is to take advantage of the fact that the sidelobe value depends on the mainlobe signal strength, and to remove the sidelobe by sequentially determining the sidelobe value corresponding to the changing reflected signal strength. It is an object of the present invention to provide a method for displaying a high dynamic range image by preventing deterioration of the displayed image due to lobes.

Next, embodiments of the sidelobe suppressing display method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a circuit diagram for implementing the display method of the present invention. For convenience of explanation, the same reference numerals are given to the same components as those in the conventional circuit shown in FIG. 1, and detailed explanation thereof will be omitted. In other words, in FIG. 4 is a beam synthesis circuit, 4 is a sidelobe discrimination circuit, 5 is a video amplifier circuit, 6 is a display, 7 is an amplifier circuit line for the X-axis side, and 8 is a line for the Y-axis side amplifier circuit. The circuit configuration is exactly the same as the conventional configuration.However, in the present invention, a memory circuit 9, a maximum value detection circuit 10, and a sidelobe calculation circuit are provided between the beam combining circuit 2 and the sidelobe discrimination circuit 4. 11.

Therefore, to explain the operation of the circuit with the above configuration, first, pulse-modulated radio waves or sound waves are transmitted by an antenna, a transmitter, etc., the reflection from a predetermined target is received by the sensor array 1, and the beam is A combining circuit 2 detects the signal strength in each direction of incidence angle. Next, the signal strength for one sector is stored in the memory circuit 9, and the maximum value detection circuit 1
0, the maximum value of the signal strength stored in the memory circuit 9 is detected. The maximum value detected in this way is taken as the main lobe value, the side lobe value is determined by the side lobe calculation circuit 11, and the side lobe determination circuit 4 compares each signal strength with the side lobe value to determine whether it is a side lobe. and when it is determined to be a sidelobe, its signal strength is deleted.0Then, the output value of the sidelobe discrimination circuit 4 is amplified by the video amplifier circuit 5 and used as the luminance signal of the display 6, as shown in FIG. The signal is supplied to the display 6 in the same manner as the circuit.

In the Zydrobe suppression display method of the present invention using the circuit system described above, as shown in FIG. 2, the sidelobe value changes as shown by the characteristic line ■ according to the main lobe signal strength (characteristic line ■). In this case, it is possible to suppress the side lobes and obtain an image without deleting the main lobe signal. In addition, in the sidelobe calculation circuit,
Since the side lobe (+i+) is calculated taking into account set noise, quantization noise, etc. in the main lobe signal, the actually calculated side lobe value does not faithfully follow the main lobe signal strength.

As described above, in the sidelobe suppression display method according to the present invention, it is possible to appropriately suppress sidelobes and display a high-intensity clean image, prevent image deterioration, and display a clear image. It has the advantage of being able to

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram implementing a conventional sidelobe suppression display method, FIG. 2 is a characteristic diagram showing the relationship between main lobe values and sidelobe values, and FIG. 3 is a sidelobe suppression display according to the present invention. 1 is a block circuit diagram illustrating one embodiment of a method; FIG. 1. Sensor array 2. Beam combining circuit 3.
... Sidelobe value setter 4 ... Sidelobe discrimination circuit 5 ... Video amplifier circuit 6 ... Display 7
...X-axis lateral amplifier rotation stepping line 8...Y-axis side amplifier turning stepping line 9...Memory circuit 10.
・Maximum value detection circuit 11...Sidelobe calculation circuit■...Characteristic line II of main rope value...Characteristic f1 line of sidelobe value by conventional method■
...When the characteristic line of the sidelobe value according to the method of the present invention is π[
Applicant: Japan Radio Co., Ltd.

Claims (1)

[Scope of Claims] (1) In radar, sonar, etc. where the reflected signal strength always changes, side rope values corresponding to the changing main rope signal strength are sequentially determined, and a side rope signal is generated based on the obtained side rope values. A sidelobe suppression display method characterized by displaying a high dynamic range image by removing . (2. In the sidelobe suppression display method according to claim 1, the sidelobe value corresponding to the main rope signal strength is determined by storing the signal strength of 17 digits in a memory circuit, and using a maximum value detection circuit. A sidelobe suppression display method in which the maximum value of the signal strength stored in the memory circuit is detected as a main lobe value, and a sidelobe value is calculated from the maximum value using a sidelobe calculation circuit. ) In the sidelobe suppression display method described in claim 1 or 2, in order to delete the sidelobe signal based on the sidelobe value, a sidelobe discrimination circuit is provided, and a sidelobe discrimination circuit is provided to distinguish between the signal strength and the sidelobe value. This method compares the sidelobe signals and removes them to display sidelobe suppression.