JPH011988A - target indicator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a target indicator, and more particularly to an image memory type target indicator that displays a fine target image and scales in a radar or sonar target display.

[Conventional technology]

BACKGROUND ART Conventionally, radar is a typical device for detecting targets on land and sea and flight oscillations in the air, and sonar is a typical device for detecting underwater targets.

The basic principle behind these is that a radar pulse or ultrasonic pulse is emitted from an antenna or transmitter, and this pulse is reflected by the target and received again. After being amplified to the level necessary for display, the distance is displayed on the display. Information and orientation information are displayed in a legible manner.

PPI display is a commonly used display method for radar, and PPI display, B slow 1 display, etc. are often used for sonar. In addition, recent advances in electronic technology, IC
, LSI, etc., there are now many devices that not only display brightness on a simple sweep axis but also store two-dimensional image data and constantly display the screen in a TV format.

[Problem that the invention seeks to solve]

However, the image memory type target display described above has the following drawbacks.

Normally, the received signal is amplified to the required level in the reception section, and then sent to the A/D conversion section at a sampling frequency determined by the memory capacity of the scan converter section, which has an image memory that stores the image on the display section in a predetermined format. After being sampled, it is written onto the memory of the scan converter section in synchronization with the write address signal that is PPI-swept by the scan converter section. In this case, there is no problem if the memory capacity in the range direction of the scan converter is sufficient for the number of pixels sampled with a sampling time of 1/2 of the transmission pulse width, but if the memory capacity is small, When the received signal is sampled at a time interval corresponding to the merit capacity, the sampling interval becomes shorter and the information is stored in the digital scan converter in a form that is omitted. If the signals stored in memory in such a state are displayed on the display section by TV-type scanning, omissions may occur in the display as shown in FIG. 5(b). Figure 5 (a) shows an image with sufficient memory capacity and no omissions, and Figure 5 (b) shows that small targets are displayed or Examples such as ■ and ■ that are omitted and not displayed are shown below. In addition, even if there is sufficient hardware, if increasing the memory capacity is meaningless due to the memory speed and display resolution of the display device, the memory must be limited as a result, and the same applies in this case. However, it has the disadvantage that it significantly impedes the operational purpose of radars and sorters for monitoring and searching targets.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image memory type target display that can eliminate the above-mentioned drawbacks, reduce memory capacity, and fundamentally eliminate omissions.

[Means for solving problems]

The apparatus of the present invention provides an A/D conversion for sampling in order to store the received signal to be displayed in the image memory in an image memory type target display that displays received signals of radar and sonar via a scan converter. a high-frequency sampling section that samples the received signal at a sampling frequency higher than a writing sampling frequency of the image memory; and a high-frequency sampling section that samples the received signal at a sampling frequency higher than the write sampling frequency of the image memory; and a maximum value detection section that sends out image data in pixel units.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. The configuration of the embodiment shown in FIG. 1 uses a sonar device as an example, and
Delivery section 1. Receiving section 2. A/D exchange section 3. Scan converter section 41 display section 5. Control unit 6. The target display 10 includes a transmitter 72, a rotation drive unit 8, etc.
．． It is composed of a scan converter section 4 and a display section 5. The A/D converter 3 of this target display 10 is a part directly related to the present invention, and the other components shown in FIG. 1 are almost the same as those of the conventional sonar device.

In FIG. 1, a reference signal 6001 is sent from the control unit 6 to the transmission unit 7, and a pulse transmission signal 7001 is amplified by the transmission unit 7.
The ultrasonic pulse is emitted from the sending and receiving section 1 as an ultrasonic pulse, and the signal reflected by the target is received by the sending and receiving section 1. The receiving section 2 amplifies this signal to a level required for the display section and outputs it to the A/D converting section 3 as a received signal 2001.

FIG. 2 is a block diagram showing details of the A/D converter 3 in FIG.
1. Latch portion 32. Maximum value detection section 33, buffer section 34
Further, the high frequency sampling section 31 includes a sampling section 311 and a high frequency sampling signal generation section 312, and the maximum value detection section 33 includes a comparison circuit 331.
and a maximum value latch section 332.

FIG. 3 is a main fluid system diagram of the embodiment of FIGS. 1 and 2. The description of the embodiment will be continued below with reference to FIG.

In the A/D converter 3, a high frequency sampling signal generator 3
12, a high frequency sampling signal 3121 corresponding to 1/2 of the transmission pulse width is supplied to the sampling section 311, samples the received signal 2001, and is provided to the latch 32 as a high frequency digital signal 3111. The latched high frequency digitized signal 3111 is sent to the maximum value latch unit 33 in the comparison circuit unit 331 of the maximum value detection unit 33.
The digital values stored in 3 are compared. The latched value of the maximum value latch unit 332 is reset each time the write sampling signal 6002 is input, and the larger value at the time of the comparison described above is stored. By sequentially comparing the write sampling signals 6002 and latching the maximum value as a result, the digitized signal 3 is sent to the buffer unit 34 for each write sampling.
It is output to the scan converter section 4 as 001.

As the digitized signal 3001, the one in which the high frequency digitized signal 3111 is the largest square among the received signals 2001 between the write sampling signals 6002 is obtained. There is no information missing in this signal, but the third
As shown in the figure, the digitized signal (300
In 1), it can be seen that information about the minute target is missing.

This digital signal 3001 is written into the scan converter section 4 in synchronization with the write address signal 6003 generated by the control section 6. Write on P shown in Figure 4.
It is a PI sweep method, and the sending/transfer section 1 is driven by a rotary drive section 8.
Sequential writing is performed corresponding to the rotation of
When it rotates once, one screen of image is obtained. When reading is performed and the wave transmitting/receiving unit 1 rotates once, one screen image is obtained. Reading is performed in the TV 1 mm gravity direction shown in FIG. 4 in accordance with the read address signal 6003 in the control unit 6 of FIG.

Output signal 400 read from scan converter section 4
1 is output to the display section 5 and displayed.

Writing to the scan converter unit 4 is performed using the blanking time of the read so as not to overlap during the read period, and the buffer memory for one ping (p i ng>) is written to the scan converter unit. It is built into 4.

A rotation angle signal 8001 of the sending/receiving section is outputted from the rotation drive section 8 to the control section 6, and supplies a necessary write/read address signal to the scan converter section 4.

FIG. 4 schematically depicts the memory arrangement of the scan converter section 4, where the horizontal memory capacity is a, the vertical memory capacity is b, and the detection distance is L (m).
(m) corresponds to b/2 (bit), and 1(
bit)·2 L/b(m ). The input received signal is sequentially written to the image display area C section using the d method of PPI sweep,
Reading is performed by the TV sweep e method.

Although this embodiment has explained the PPI method display, it is easy to use the A/D converter 3 similarly in the case of B scope, A scope, etc. so that information in the received signal is not omitted. It can be implemented.

〔Effect of the invention〕

As explained above, according to the present invention, in an image memory type target indicator of a radar or sonar, the A/D converter receives the write sampling signal to the scan converter within the time interval so as to prevent omission of a fine target image. By providing a control means that detects the peak value of the signal and writes this peak value to the scan converter, it is possible to fundamentally eliminate omissions in the fine target image and to reduce the memory capacity.

Furthermore, even if there is sufficient hardware memory capacity, there is no point in increasing the memory capacity due to the memory speed and display resolution of the target display, and the same effect can be obtained when memory has to be limited. effective.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing details of the A/D converter 3 in FIG. 1, and FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention. Wave family diagram of the example, No. 4
5(a) is a display reference diagram showing a normal display example; FIG. 5(a) is a display reference diagram showing a normal display example;
b) is a display reference diagram showing an example of display in which the small target image of Fig. 5(a) is omitted. 1... Sweeping/transfer section, 2... Receiving section, 3... A/D
Conversion section, 4... Scan converter section, 5... Display section, 6... Control section, 7... Transmission section, 8... Rotation drive section, 10... Target indicator, 31. ...High frequency sampling section, 32...Latch section, 33...Maximum value detection section, 34...Buffer section, 311...Sampling section, 312...High frequency sampling signal generation section, 33
1... Comparison circuit section, 332... Maximum value latch section.

Claims (1)

[Claims] In an image memory type target display that displays radar and sonar reception signals via a scan converter,
a high frequency sampling section that samples the received signal at a sampling frequency higher than a write sampling frequency of the image memory for an A/D conversion section that samples the received signal to be displayed in order to store it in an image memory; A target indicator comprising: a maximum value detection section that detects the maximum value from the sampling values output from the sampling section and sends it to the scan converter as image data in units of pixels.