JP2002116250A - Radar signal transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remotely transmit radar video in real time, while maintaining conventional level image quality by a narrow band or lower speed transmission line than in the conventional system. SOLUTION: Digitized radar video is stored at a frame memory 5 in terms of polar coordinates address, a JPEG compression device 6 reads the radar video from the frame memory 5 into an inner memory and compresses and converts the radar video into a JPEG file format. A communication control device 7 converts a JPEG file and periodical data from a period measurement counter 8 into packets and sends them to a low-speed transmission line 3. A receiver converts the data into each file by a communication control device 9, and the radar video is decoded by a decoder 10 and is written into a frame memory 11 successively. The data are read by the PPI scanning of the polar coordinates address, are D/A-converted, and are outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the field of radar signal transmission technology for transmitting a radar video signal from a radar site to a remote place and observing a radar image with a radar indicator at a remote place.

[0002]

2. Description of the Related Art In conventional radar signal transmission technology,
As shown in FIG. 2, a transmission trigger, an antenna rotation signal, and a video signal are converted into a transmission format using a wideband (or high-speed) transmission path 19 to realize real-time transmission. As a broadband (high-speed) transmission device, a baseband transmission method (analog modulation method), a digital PCM transmission method, an optical transmission line, and the like are used. The baseband transmission method is a method in which a radar video signal is dropped to the frequency band of a transmission line and transmitted via an analog line together with a transmission trigger and an antenna rotation signal. Such an analog line is mainly used for transmission of television images. It is devised to use the line that is used. Since the frequency band of the television image is about 6 MHz, the frequency band of the radar video signal is also narrowed to about 6 MHz for transmission.

[0003] The digital PCM transmission method is currently the main method instead of the analog line in order to increase the band efficiency of the transmission path. In the case of the Japanese-U.S. System, the transmission rate is 1.5 Mbps, but the transmission of radar video signals occupies about 6 Mbps. This is equivalent to about 96 telephone calls.
An optical transmission line is a system for transmitting data in baseband using an optical cable.
It is conceivable to use the optical leased line service provided by the above, but all of them are costly.

FIG. 2 is a block diagram showing a configuration of a conventional radar signal transmission apparatus using an analog line or an optical transmission line having a bandwidth of about 6 MHz as a broadband transmission line. On the radar site side, the A / D converter 15 converts the radar video signal input from the radar device into a digital signal, and sends the digital signal to the band controller 16. The band controller 16 controls the frequency band of the radar video to match the frequency band of the transmission path.

For example, if the frequency band of radar video is 8 MHz and the transmission path is the main line for transmitting television images, the frequency band is 6 MHz as described above. . The signal subjected to the band control in this manner is again converted into an analog signal by the D / A converter 17 and sent to the addition circuit 18, where it is added to the antenna rotation signal and the transmission trigger inputted from the radar device, and is added to the broadband transmission path. At 19, it is transmitted to the remote site.

On the remote side, the received radar video signal is converted into a digital signal by the A / D converter 20, and the band controller 21 performs band control for returning the radar video to the original video band. The signal is converted into an analog signal by the A converter 22 and sent to the radar indicator 13. On the other hand, the separator 23 separates the antenna rotation signal and the transmission trigger from the signal input from the wideband transmission path 19 and sends the signal to the radar indicator 13 to
I scanning is performed.

FIG. 3 shows a high-speed transmission path of 6 Mbps.
FIG. 2 is a block diagram showing a configuration in the case where a digital PCM line of a certain degree is used. 2 is the same as that shown in FIG. 2 up to the point where band control is performed on the radar site side, and thereafter, the data is converted into serial bits by a parallel / serial converter 24.
After that, a frame is formed by the frame encoder 25. At this time, the antenna rotation signal and the transmission trigger are also put on the frame, and both are transmitted to the remote place by the digital PCM line 26.

At the remote site, the frame decoder 27 grasps the break of the frame, and then sends it to the serial / parallel converter 28 and the separator 23. Serial / parallel converter 2
At 8, the data is converted into parallel bits and sent to the band controller 21. The following is the same as in FIG. 2. The separator 23 extracts the antenna rotation signal and the transmission trigger and sends them to the radar indicator 13 as in FIG.

[0009]

In the conventional radar signal transmission system described above, although the frequency band including the radar video is transmitted in a narrow range, the frequency band of the wide band is still required to secure the image quality on the receiving side. Transmits radar video containing components. Therefore, there is a problem that the transmission path must have a wide band and a high speed, and the transmission cost is high.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, it is an object of the present invention to transmit a radar video capable of displaying an image of the same quality as a conventional one in a remote place at a relatively low speed (narrow band). It is an object of the present invention to provide a radar signal transmission device capable of transmitting data via a line.

[0011]

In order to achieve the above object, a radar signal transmitting apparatus according to the present invention comprises a radar signal transmitting apparatus for transmitting a radar signal, and a radar signal receiving apparatus for receiving a radar signal. The invention of the restoration device,
The radar signal compression transmission device has the following components. (B) receiving the radar video signal from the radar device,
A / D converter for converting this into a digital signal (b) A frame memory for storing the radar video digital signal in a storage element in accordance with an address instruction based on an antenna rotation signal from a radar device and a transmission trigger (c) JPE that sequentially reads radar video digital signals from frame memory and performs JPEG compression processing
G compression device (d) Period measurement counter that measures the antenna rotation signal from the radar device and the transmission trigger period and outputs the period information (e) The same transmission of the compressed signal from the JPEG compression device and the period information from the period measurement counter Communication control device that processes data so that it can be transmitted simultaneously on a line

The radar signal receiving / restoring device has the following components. (B) a communication control device that receives a radar signal from the radar signal compression transmission device transmitted through a transmission line, and separates and outputs a compressed signal and period information; and (b) receives a compression signal from the communication control device. JPEG decompression device for decompression processing (c) Frame memory for sequentially writing the decompression signal from the JPEG decompression device (d) Receiving cycle information from the communication control device and transmitting an antenna rotation signal based on this cycle information A period counter that outputs a trigger (e) A D / A converter that converts a radar video digital signal read from the frame memory into an analog signal in accordance with an address signal based on an antenna rotation signal from the period counter and a transmission trigger.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The difference between the present invention and the conventional device is that
JPEG (Joint Photographic Expert Gr) which is completely different from the conventional band control as a compression method for radar video
oup) The compression method is used. In the JPEG compression method, if the image quality required in a remote place is about the same as the conventional one, the compression rate of the compression applied to the radar video on the radar site side is far more than that in the conventional band control. Can be bigger. For this reason, there is an advantage that the transmission path can be of a much narrower band (low speed) than in the past.

Therefore, a telephone line (for example, an ISDN line of NTT or a general analog line) can be used as a transmission path via a line interface such as a router or a modem in addition to a LAN interface, so that transmission costs can be greatly reduced. be able to.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a radar signal transmission device according to the present invention. The radar signal compression / transmission device 1 is located on the radar site side, and the radar signal reception / restoration device 2 is located on the remote site side. A radar video signal is input to an A / D converter 4 of the radar signal compression transmission device 1 from a radar device (not shown), converted into a digital signal, and sent to a frame memory 5. An antenna rotation signal and a transmission trigger are input to the frame memory 5 from the radar device, and the radar video digital signal from the A / D converter 4 is stored in the storage element in accordance with a polar coordinate address instruction based on the signal. The JPEG compression device 6 takes the radar video from the frame memory 5 into the internal memory and compresses and converts it into a JPEG file format. The compression-converted signal is sent to the communication control device 7.

The antenna rotation signal and the transmission trigger are also input to a period measurement counter 8, where each period is measured, and the period data is sent to the communication control device 7, which is converted into a packet with the above-described JPEG file. Or via a LAN port via a router or a wireless LAN equipped with a LAN interface or via a modem port to an analog telephone line.

The digital data transmitted through the transmission line is input to the communication control unit 9 of the radar signal receiving / restoring unit 2 on the remote side, and is classified into different files.
Radar video compressed to JPEG files is J
The data is sent to the PEG decompression device 10, where it is subjected to a decompression process for compression, and is sequentially written to the frame memory 11.

On the other hand, the cycle counter 14 receiving the cycle data from the communication control unit 9 generates an antenna rotation signal and a transmission trigger based on the cycle data, and sends them to the frame memory 11 and the radar indicator 13. Reading from the frame memory 11 is performed by performing an address scan corresponding to the PPI scan with a polar coordinate address based on the antenna rotation signal and the transmission trigger.

The read digital radar video is
After being converted to an analog video signal by the D / A converter 12, it is sent to the radar indicator 13. Since the radar indicator 13 performs the PPI scanning by the antenna rotation signal and the transmission trigger, the same PPI image as the indicator (not shown) on the radar site side can be seen.

[0020]

As described above, the radar signal compression transmission apparatus, which is the transmission apparatus of the present invention, transmits radar video,
JP with much higher compression ratio than conventional bandwidth control
Since the signal is compressed by the EG method and decompressed by the radar signal receiving and restoring device on the receiving side to decompress the signal, the transmission path from the transmitting side to the receiving side is a high-speed (wideband) transmission conventionally used. Transmission line with a much lower speed (narrow band) than the line, such as analog telephone line, ISDN, LAN,
Since transmission can be performed in real time over a wireless LAN or the like, transmission costs can be kept very low, and these lines are widespread, and radar video can be transmitted and received in such places. The effect is that the degree of freedom of the location of the radar station is extremely high.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a radar signal transmission device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional radar signal transmission device using a wideband analog line or an optical transmission line.

FIG. 3 is a block diagram showing a configuration of a conventional radar signal transmission device using a high-speed digital PCM line.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 radar signal compression / transmission device 2 radar signal reception / reconstruction device 3 low-speed transmission line 4 A / D converter 5 frame memory 6 JPEG compression device 7 communication control device 8 cycle measurement counter 9 communication control device 10 JPEG decompression device 11 frame memory 12 D / A converter 13 Radar indicator 14 Period counter 15 A / D converter 16 Band controller 17 D / A converter 18 Adder circuit 19 Broadband transmission line 20 A / D converter 21 Band controller 22 D / A conversion 23 Separator 24 Parallel / serial converter 25 Frame encoder 26 Digital PCM line 27 Frame decoder 28 Serial / parallel converter

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takahiro Itagaki 5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan Radio Co., Ltd. (72) Inventor Katsutoshi Ashida 5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan Radio Inside (72) Inventor Tsunega Kinosaki 5-1-1 Shimorenjaku, Mitaka-shi, Tokyo Japan Radio Co., Ltd. (72) Inventor Shogo Hayashi 1-1-10 Egawa, Koto-ku, Tokyo 1413 F-term (reference 5C059 KK00 MA00 RA01 RD03 RE02 SS06 UA02 UA05 UA34 5J064 AA05 BA18 BB13 BC01 BC06 BC07 BD02 CA02 5J070 AA02 AH01 AH31 AJ13 BG19

Claims (3)

[Claims] 1. A radar signal compression and transmission device comprising the following components. (B) receiving the radar video signal from the radar device,
A / D converter for converting this into a digital signal. (B) A frame memory for storing the radar video digital signal in a storage element in accordance with an address instruction based on an antenna rotation signal from a radar device and a transmission trigger. JPE that sequentially reads radar video digital signals from frame memory and performs JPEG compression processing
G compression device (d) Period measurement counter that measures the antenna rotation signal from the radar device and the transmission trigger period and outputs the period information (e) The same transmission of the compressed signal from the JPEG compression device and the period information from the period measurement counter Communication control device that processes data so that it can be transmitted simultaneously on a line 2. A radar signal receiving / restoring device comprising the following components. (B) a communication control device that receives a radar signal from the radar signal compression transmission device transmitted through a transmission line, and separates and outputs a compressed signal and period information; and (b) receives a compression signal from the communication control device. JPEG decompression device for decompression processing (c) Frame memory for sequentially writing the decompression signal from the JPEG decompression device (d) Receiving cycle information from the communication control device and transmitting an antenna rotation signal based on this cycle information A period counter that outputs a trigger (e) A D / A converter that converts a radar video digital signal read from the frame memory into an analog signal in accordance with an address signal based on an antenna rotation signal from the period counter and a transmission trigger. 3. A radar signal transmission device comprising the radar signal compression transmission device according to claim 1 and the radar signal reception restoration device according to claim 2.