JPS6246279A - Radar-scanning converter - Google Patents

Abstract

PURPOSE:To enable a scanning conversion to be performed with a high resolution by providing means for forming a region requiring no write and means, based on said formed region, for forbidding a write in a video memory for radar image information in said region. CONSTITUTION:A radar-scanning converter is provided with a cursor display 9, an orthogonal coordinate map 10, a polar coordinate map 11, a transfer circuit 12 and a map memory 13. The display 9 conducts a control for displaying a cursor, writes the cursor in the map 10, and conducts the processing to register or delete a figure (map) for indicating write forbidden sections in or from the map 10, respectively, on the basis of the position of the cursor. The registered map is read by a television timing controller 7 and the registration and deletion of the maps can be monitored by mixing the read map with preceding video signals. Thus, the map registered while monitoring a screen is written in the map 11 by the circuit 12 and, when the map 11 is given bearing information, it can be confirmed that in what position of orthogonal coordinates the map is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to an airport surface detection radar (Airport 5ar
Face Detection Equipment
Regarding the display of ASDE (hereinafter referred to as ASDE), in particular, ASDE's radar image signal is displayed as Te1evision (hereinafter referred to as T
The present invention relates to a scan conversion device for converting to raster (referred to as V).

(Prior Art) Conventionally, this type of equipment has been set up in a position that provides a good view of the airport for airport surface monitoring, and its images are monitored by the airport's control tower and used for air traffic control. ASDE is a short-range radar device that covers the airport surface, and it needs to detect and display aircraft, vehicles, etc. moving on the runway and taxiway within the airport. The display must be easy to read.

The conventional ASDE described above takes special measures for the radar and display device to improve visibility at the control tower. Radar images are displayed using the PPI method in synchronization with the antenna's radio wave transmission scan, so the repetition rate of display (updating of the display screen) is low, so a phosphor cathode ray tube (hereinafter referred to as CRT) with a long afterglow characteristic is used. However, because the afterglow brightness is low, ASDE display devices must further darken the CRT tube surface by using a hood to cover the display surface.
It is also effective to increase the radar scanning speed (antenna rotation speed) and increase the display repetition rate. However, its performance was still insufficient for use in control towers. The reason is that the image is so dark that it is necessary to use a hood, and the controller cannot monitor the area more than 2 Å at the same time, and other precautions are disrupted in order to view the ASDE image.

Therefore, in order to solve this drawback, ASDE's scan conversion device that converts radar images into TV images converts radar images into TV images that can be monitored from the control tower with high brightness and without the use of a hood. methods have begun to be adopted.

FIG. 4 shows a block diagram of a conventional scan conversion device.
The operation will be briefly described below.

Analog radar video from the radar receiver is A/
The D converter 1 converts it into a digital signal. On the other hand, an azimuth signal θ indicating the azimuth of the antenna is sent to the address coordinate conversion circuit 3.
Then, the radar trigger Tr that serves as a reference for counting the distance R in the relevant direction is input. The digital signal from the A/D converter 1 is applied to the buffer memory 2, and is stored in correspondence with the distance in each direction according to the signal from the address coordinate conversion circuit 3. In the address coordinate conversion circuit 3, the position (address) of the radar video expressed in polar coordinates of azimuth θ and distance R is displayed on the corresponding orthogonal coordinates (X, Y
) and output to the address control section 4. This address signal is applied to the write/read controller 5, which reads out the radar video stored in the buffer memory 2 and writes it into the video memory 6.

This reading and writing is performed at an address on the rectangular coordinates on the video memory 6 that corresponds to an address on the polar coordinates of the radar video read out from the buffer memory 2. In this way, the digitized radar and thio are stored in a video memory 6 that can be addressed using orthogonal coordinates.
To read out the 0-th order video memory 6 stored above, a TV raster scan signal is output from the TV timing control section 7, passes through the address control section 4, and is read out from the video memory 6 by the write/read control section 5. The storage element is read out while horizontally and vertically scanning based on orthogonal coordinates. The read signal is converted into an analog signal by the D/A converter 8, and TV raster scanning is performed in synchronization with the readout scanning signal.
It is added to the display using a di-cathode ray tube for V, and it is
Similarly, a radar image display that can be observed in a bright place can be obtained.

(Problem to be solved by the invention) ASDE video signals require high resolution, so the transmission frequency is high and the transmission pulse width is short, and the antenna scanning speed is high (high rotation rate and high data rate). Therefore, high-resolution scan conversion must be performed for ASDE display.

Scan conversion involves coordinate conversion of the video signal from the ASDE to a high-resolution TV video memory, and writing processing must be performed at high speed, and the speed required for this purpose is approximately as follows.

Now, when the radar detection distance is -2NM, the video band is 1-30MHz or less, the sampling period is -30nS, the number of display cells is 2 x 113510.03 capes 824 in radius.

Also, radar scan -----60rp■P RF
-----When set to 4096pps, the quantum number of one screen (
Number of samples) is 4096 x 824 = 3.3 per second
75,104, which requires processing of a huge amount of data.

Since this information cannot be processed as is, it cannot be realized unless some method is taken to reduce the amount of data.This is because writing 3.375,104 samples per second requires the writing time per sample. is about 3
It becomes 00nS. Moreover, this value is calculated assuming that all the time is spent writing, and in reality it is for displaying TV images,
It is necessary to read the video signal from the memory in synchronization with the raster scan.

If the readout is 30H2 per second using the interlace method, and the number of readouts per raster is N, then the number of rasters (1
64g) The time of x30xNxt (reading time) is occupied exclusively for reading.

N=32. When t=300 ns, the writing time is halved since 47% is occupied.Therefore, there is a problem that high-resolution scan conversion cannot be performed with this.The purpose of the present invention is to solve the problems of the prior art described above. In consideration, ASDE
Among the radar image information obtained by the system, information on parts that do not require high-resolution images (especially image information on fixed objects such as buildings) is displayed as an image by an alternative means without writing it to the video memory of the scan conversion device. To provide a radar scan conversion device that performs high-resolution scan conversion by allocating the saved time to the time necessary for writing radar image information truly necessary for air traffic control into a video memory and reading it from the video memory. It is something.

(Means for Solving the Problems) The airport surface usually has a runway 1, a taxiway, an apron, buildings, etc., as shown in Figure 3. Detection of the airport surface only needs to be performed on the aforementioned road surface and apron, and there is no need to include any radar image information in the video memory for hatched areas outside these areas.

Therefore, the radar scan conversion device of the present invention registers an area in the video memory where it is not necessary to write radar image information, and while referring to the boundary of this area, radar image information of only the necessary area is transferred from the buffer memory to the video memory. Therefore, the radar conversion device of the present invention is broadly divided into means for creating the above-mentioned write-free area, and means for prohibiting writing of radar image information of the area into the video memory based on the created area. has.

That is, the radar scan conversion device of the present invention includes: a cursor display means that can partition an arbitrary area on a cathode ray tube display after scan conversion using an electronic cursor; a Cartesian coordinate map that can store the partitioned area in an orthogonal coordinate system; The divided area stored in the orthogonal coordinate map is stored in a polar coordinate system of direction and distance, and the intersection point where the azimuth line when viewing the divided area from a position corresponding to the radar device installation point intersects with the dividing line of the divided area a polar coordinate map for storing and registering the orthogonal coordinate values of; an address coordinate conversion circuit that receives the orthogonal coordinate address of the intersection point from the polar coordinate map and skips and outputs the orthogonal coordinate address on the azimuth line in the divided area; The present invention is characterized by comprising: a transfer circuit that converts and transfers the map from an orthogonal coordinate map to a polar coordinate map; and a map storage unit that stores and stores the divided area pattern.

(Function) The radar scan conversion device of the present invention has the above configuration, and while the operator observes the radar image on the display, there is no need to write the radar image to the video memory using the cursor display means. When a certain area is partitioned with a cursor, the partitioned area is stored in the orthogonal coordinate map. This divided area is converted and transferred to a polar coordinate map by a transfer circuit. In the polar coordinate map, the orthogonal coordinate values of points outside the partitioned area, where the azimuth line intersects with the partition line of the partitioned area, are registered by referring to the orthogonal coordinate map.

Then, the polar coordinate map counts the distance in that direction based on the input direction information and points (
Distance information R to the starting point of the partitioned area), and Cartesian coordinate values ( X2.Y2) is output. The address coordinate conversion circuit receives a signal from the polar coordinate map and writes the radar image information from the buffer memory to the video memory from the coordinates of distance R1 (Xl, Yt) to the coordinates of distance R2 (
Skip (skip) up to Xa, Y2).

The time saved by this skipping can be allocated to the time for writing and reading areas that require high-resolution scan conversion, so that higher-resolution scan conversion becomes possible.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Note that the structural blocks numbered 1 to 8 in the figure have the same functions as the blocks labeled with the same numbers in the structural block diagram of the conventional device shown in FIG. 4, and therefore the explanation thereof will be omitted.

The apparatus according to the embodiment of the present invention is characterized by having a cursor display section 9, an orthogonal coordinate map 10, a polar coordinate map 11, a transfer circuit 12, and a map storage section 13. The cursor display unit 9 performs control to display the cursor, writes the cursor on the orthogonal coordinate map 10, and also draws a figure (hereinafter simply referred to as map) indicating a write-prohibited area on the orthogonal coordinate map 10 based on the cursor position. Performs registration and deletion processing.

Since the orthogonal coordinate map 10 has the same orthogonal coordinate memory address structure as the video memory 6, the registered map is read out by the TV timing control section 7 and mixed with the previous video signal, thereby registering or deleting the map. can be monitored. The map registered while monitoring the screen is written into the polar coordinate map 11 by the transfer circuit 12. This converts the address of the radar video from polar coordinate display to rectangular coordinate display, and the orthogonal coordinate map 10 is This can be done by referring to it.

The polar coordinate map 11 is a map in which the write-protected area described above has been rewritten into a format that can be referenced using a polar coordinate system.

When the polar coordinate map 11 is given azimuth information θ, it is possible to know at which position on the orthogonal coordinates the map is created.

When writing from the buffer memory 2 to the video memory 6, only the necessary portion is stored based on this information.

Next, the present invention will be explained in detail. Cursor display section 9
displays a cursor (+ mark, etc.) on the screen as shown in Figure 2. Furthermore, the cursor is moved to the target position according to the operator's instructions, and the position is registered (by matching while watching the radar video on the monitor). In the initial video writing, the radar repetition period is thinned out and written to the video memory 6 (almost the entire screen can be written after several scans).
This allows the map to be created by referring to this image.

A map is an area surrounded by a combination of lines whose start and end points are indicated by a cursor. When the sweep created by the transfer circuit 12 passes through this map, the map start coordinates and end coordinates in that direction are stored. FIG. 2 illustrates this conversion. In the sweep in the direction θ, the orthogonal coordinates of the distance R1 are used as the starting coordinates, and the X coordinates of the distance R2 are used as the starting coordinates.
The Y coordinate is stored as the end coordinate. Conversion is distance (R)
Synchronize with the counter and calculate the X and Y addresses of the orthogonal coordinates by calculating R-sin θ and R-cos θ. When the orthogonal coordinate map 10 is referenced and the R1 point is reached, the X, Y address values are 1 in the polar coordinate map 11. Sequentially advance the R counter and orthogonal coordinate x at the R2 point
2. Register y2 in the same way. Reading from the polar coordinate map 11 uses the azimuth information θ as an address and uses R, , x , , Y
1. and R,,X2. On the other hand, video data is stored in the buffer memory 2 in correspondence with distance.

The write address from the address coordinate conversion circuit 3 is a distance R1
When reaching (Xl, Yt), write address (X
2. Replace R with R2). By doing this, the data on the buffer memory 2 is
It is skipped during R2.

The map information once created can be registered in the map storage section 13, so that it is not necessary to input initial data by starting up the device again. The map storage section 13 can be realized using a floppy disk device or a non-volatile memory such as a bubble memory.

(Effects of the Invention) With the configuration and operation described above, the radar scan conversion device of the present invention displays a high-resolution image in a radar-received image, and therefore displays a cursor in advance for areas that do not require high-resolution scan conversion. A figure (map) indicating an area where high-resolution video is not required is created electronically through an operation, and based on this map, writing from the buffer memory to the video memory is skipped for that area, saving time for writing and reading unnecessary areas. , this time is allocated to writing and reading radar signals in areas that require high-resolution scan conversion, so the present invention is effective in situations where there are restrictions on the time that can be used for writing and reading. It has the advantage of being able to perform scan conversion with higher resolution than a scan conversion device that does not apply this method.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure is an explanatory diagram of map creation control, Figure 3 is an airport layout diagram,
FIG. 4 is a block diagram showing the configuration of a conventional radar scan conversion device. 1... A/D converter, 2... Buffer memory, 3... Address coordinate conversion circuit, 4.
... Address control section, 5 ... Write/read control section, 6 ... Video memory, 7 ...
...TV timing control unit, 8...D/A converter, 9...cursor display section, 10...
・Orthogonal coordinate map, 11...Polar coordinate map, 12...Transfer circuit, 13...
Map memory department.

Claims (1)

[Claims] a cursor display means capable of partitioning an arbitrary area using an electronic cursor on a cathode ray tube display after scan conversion; an orthogonal coordinate map capable of storing the partitioned area in an orthogonal coordinate system; and the partitions stored in the orthogonal coordinate map. A polar coordinate map that stores an area in a polar coordinate system of direction and distance, and stores and registers a rectangular coordinate address of an intersection point where an azimuth line intersects with a demarcation line of the demarcated area when the demarcated area is viewed from a position corresponding to a radar device installation point; an address coordinate conversion circuit that receives a rectangular coordinate address of the intersection point from the polar coordinate map and skips and outputs the orthogonal coordinate address on the azimuth line in the divided area; converts and transfers the divided area from the orthogonal coordinate map to a polar coordinate map; A radar scan conversion device comprising: a transfer circuit; and a map storage unit that stores and stores the divided area pattern.