JPH095432A - Radar system for air traffic control - Google Patents

Abstract

(57) [Abstract] [Purpose] A radar system for air traffic control, which utilizes both positioning values of a radar system and GPS with high accuracy and has excellent aircraft position display accuracy and can display the position of an aircraft in a blind area. provide. A reflector station 6 including a reflector 7 for reflecting radar radio waves from the radar station 2 and a GPS receiver 8 is provided, and both coordinates of world standard coordinates and radar measurement coordinates by the GPS receiver 8 of the reflector station 6 are provided. By utilizing the difference of 1), the conversion from the world standard coordinates of the GPS compatible aircraft 1A to the radar system coordinates is corrected. The converted coordinates of the GPS-compatible aircraft 1A are superimposed and displayed on the radar coordinate display device. The GPS-compatible aircraft 1B is displayed even in the radar blind area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a positioning value by radar and NAVSTAR GPS (Navigation Satellite Time).
and Ranging Global Positioning System, GPS
(Hereinafter abbreviated)) for the air traffic control radar system that displays the position of the aircraft using both of the positioning values.

[0002]

2. Description of the Related Art As a radar system for air traffic control used to grasp the position and mutual distance of an aircraft in flight, an airport surveillance radar (ASR) is used.
Radar) system, airway surveillance radar (ARSR: Air)
There is a Route Surveillance Radar (SSR) system and a Secondary Surveillance Radar (SSR) system. The ASR system provides approach control and departure control for aircraft around the airport (within 60 to 70 nautical miles). AR
The SR system monitors aircraft within 200 nautical miles centered on the antenna. Both the ASR system and the ARSR system radiate a radio wave from an antenna and measure the distance and azimuth of the target by the reflected wave from the target. SSR
The system sends code pulses from the ground on radio waves,
The aircraft encodes the aircraft identification code and altitude with the transponder installed and returns it to the ground station. By using the SSR system together with the ASR system and the ARSR system, the radar station on the ground can know the aircraft identification code and altitude in addition to the distance and direction of the aircraft as seen from the radar station.

The ASR system and the ARSR system do not require any equipment on the aircraft side, while the aircraft must be equipped with a transponder to support the SSR system. In recent years, the importance of SSR systems has increased with the development of air traffic, and almost all aircraft in Japan are obliged to install this transponder.

The above radar system is a system for measuring the position of an aircraft on the ground.
As one of the navigation systems that the aircraft knows its position,
There is GPS.

GPS is a system for measuring its own accurate three-dimensional position with reference to a group of satellites arranged so as to cover the entire globe, and its accuracy is generally about 10
It is less than 0 m, which is better accuracy than the radar system. In order to know the position by GPS, the aircraft receives the coded signal radio wave from the satellite and performs positioning calculation processing.
It is necessary to install a PS receiver. Due to its high accuracy, a system is expected in the future in which the positioning value acquired by the on-board GPS receiver is transmitted to the ground via a communication medium such as a communication satellite and used for air traffic control. However, at present, due to the cost required for the on-board equipment, not all aircraft support GPS.

Conventionally, radar system coordinates, which are two-dimensional coordinates of distance and azimuth measured by radar, and world standard coordinates, which are positioning values by GPS, have not been displayed on the same screen.

FIG. 9 is a diagram for explaining a display example of a radar coordinate display device by a conventional air traffic control radar system and a global standard coordinate display device by GPS. FIG. 9A shows an aircraft to be displayed. FIG. 9 is a diagram showing an arrangement of aircraft projected onto a plane perpendicular to the ground surface, and in contrast to this arrangement, a screen of a radar system coordinate display device (hereinafter referred to as a radar coordinate system screen) shows a GPS in FIG. 9 shows the screen of the world standard coordinate display device (hereinafter referred to as the world standard coordinate system screen).
It is displayed as shown in (c). In the figure, aircraft 1A,
1B is an aircraft compatible with both GPS and SSR. The radar station 2 is positioned from the aircraft 1A by (i) radar measurement coordinates (distance r and direction φ with respect to the radar station), (ii) aircraft identification code and altitude h by SSR, and (iii) radio waves from the GPS satellite group 3. Obtain three types of information: three-dimensional world standard coordinates. Here, the information of (iii) is a communication satellite,
It is transmitted to the radar station via a communication medium such as a VHF data link or SSR mode S. The aircraft 1B has a radar station 2
Since there is an obstacle between the radar station 2 and the vehicle and it is located in the blind area, the radar station 2 receives the information (i
ii) get only The aircraft 1C is an SSR-compliant and non-GPS-compliant aircraft, and the radar station 2 uses the information (i)
(ii) and get. The aircraft 1D is an aircraft that does not support SSR or GPS, and the radar station 2 uses (i)
Only get

Based on these pieces of information, the radar coordinate system screen of the radar station 2 is as shown in FIG.
The respective shadows 4A, 4C, and 4D of A, 1C, and 1D are displayed, but the aircraft 1B in the blind area is not displayed.

The world standard coordinate system screen is shown in FIG. 9 (c).
As shown in, each of the features 5A and 5B of the aircraft 1A and 1B.
Is displayed, but the non-GPS compatible aircraft 1C and 1D are not displayed.

[0010]

In the conventional air traffic control radar system, since the positioning value with high accuracy measured by GPS is not used, it is impossible to obtain the positioning accuracy higher than that determined by the radar technology. was there. There was also a problem that aircraft in blind areas such as the San'in area where radar waves could not reach cannot be positioned and displayed.

On the other hand, the display of the position of the aircraft in world standard coordinates using GPS can be displayed more accurately than the radar, but it is practically used as an air traffic control system in the present situation where the rate of the aircraft to support GPS is low. There was a problem of lacking sex.

To solve the above problems, even if the positioning values obtained from both the radar system and GPS system are displayed on the same screen, the radar system and G
Since PS is another system based on a principle different from that of PS, universality is not guaranteed in compatible use between positioning values of both systems, and positioning values of both systems cannot be simply confused and used. .

The present invention has been made to solve the above problems. A first object of the present invention is to make good use of both the positioning values of the radar system and GPS with each other with high accuracy, so that the position display accuracy of the aircraft is excellent. It is to provide a radar system for air traffic control.

A second object is to provide an air traffic control radar system capable of displaying the position of an aircraft in a blind area.

A third object of the present invention is to provide an air traffic control radar system with improved aircraft tracking processing accuracy.

[0016]

According to a first aspect of the present invention, an air traffic control radar having means for emitting a radar radio wave from a radar station to measure two-dimensional radar system coordinates of a distance and a direction of a flying aircraft. The system includes a reflector station that includes a GPS receiver and a reflector that reflects radar radio waves from the radar station, and the radar station includes a G receiver that includes the GPS receiver.
A means for receiving the world standard coordinates of the aircraft measured by the GPS receiver, which is notified from the PS compatible aircraft, is converted, and the world standard coordinates of the GPS compatible aircraft are converted into the radar system coordinates in the radar coordinate system. In the conversion, one of the latitude and longitude of the world standard coordinates before conversion and the converted radar system coordinates is the world standard coordinates measured by the GPS receiver provided in the reflection station and the radar measurement coordinates of the reflection station. It is corrected by using the difference.

According to a second aspect of the present invention, the radar station has a radar coordinate display device for displaying the radar measurement coordinates measured by the radar, and the GPS-compatible aircraft is the world measured by the GPS receiver provided in the reflection station. The position is displayed on the radar system coordinate display device by the converted radar system coordinates corrected using the difference between the standard coordinate and the radar measurement coordinate of the reflection station, and the GPS non-compliant aircraft is displayed on the radar system coordinate display device by the radar measurement coordinate. Is done.

In the third aspect of the present invention, the tracking processing of the GPS compatible aircraft is corrected by using the difference between the world standard coordinate measured by the GPS receiver provided in the reflection station and the radar measurement coordinate of the reflection station. It is characterized in that it is performed by collating system coordinates with radar measurement coordinates.

According to a fourth aspect of the present invention, there is provided an air traffic control radar system having means for emitting a radar radio wave from the radar station to measure two-dimensional radar system coordinates of a distance and an azimuth of an aircraft in flight. It has a reflection station equipped with a reflector that reflects radar radio waves and a GPS receiver, and the radar station is informed by a GPS-compatible aircraft equipped with the GPS receiver, and the world of the aircraft measured by the GPS receiver. A radar for an SSR-compatible aircraft including a means for receiving standard coordinates and a global standard coordinate display device for displaying the position of the GPS-compatible aircraft by the world standard coordinates consisting of altitude and latitude and longitude, and equipped with a secondary surveillance radar transponder. The measurement coordinates are converted into the conversion longitude and latitude in the world standard coordinate system using the altitude reported by the secondary surveillance radar transponder, and in the conversion, GP either the radar measurement coordinate conversion longitude and latitude before conversion aircraft, with the reflection station
It is corrected by using the difference between the world standard coordinate measured by the S receiver and the radar measurement coordinate of the reflection station, and the SSR compatible aircraft is position-displayed on the world standard coordinate display device by the converted longitude and latitude. .

[0020]

According to the first aspect of the present invention, when the world standard coordinates of the GPS compatible aircraft are converted into the converted radar system coordinates in the radar coordinate system, either the latitude and the longitude of the world standard coordinates before the conversion or the converted radar system coordinates. One is corrected by using the difference between the world standard coordinates measured by the GPS receiver provided in the reflection station and the radar measurement coordinates of the reflection station.

In the second aspect of the present invention, the GPS-compatible aircraft uses the converted radar system coordinates corrected by the difference between the world standard coordinates measured by the GPS receiver provided in the reflection station and the radar measurement coordinates of the reflection station. The position is displayed on the system coordinate display device, and the GPS non-compliant aircraft is displayed on the radar system coordinate display device according to the radar measurement coordinates.

In the third aspect of the present invention, the tracking processing of the GPS compatible aircraft is corrected by using the difference between the world standard coordinates measured by the GPS receiver provided in the reflection station and the radar measurement coordinates of the reflection station. This is performed by collating the system coordinates with the radar measurement coordinates.

In the present invention, the radar measurement coordinates of the SSR compatible aircraft equipped with the secondary surveillance radar transponder are converted into the conversion latitude and longitude in the world standard coordinate system using the altitude reported by the secondary surveillance radar transponder. In this case, one of the radar measurement coordinates before conversion of the aircraft and the conversion latitude and longitude uses the difference between the world standard coordinates measured by the GPS receiver provided in the reflection station and the radar measurement coordinates of the reflection station. The SSR-compatible aircraft is position-displayed on the world standard coordinate display device according to the converted latitude and longitude.

[0024]

Next, embodiments of the present invention will be described with reference to the drawings. It should be noted that, in the drawings, similar components are denoted by the same reference numerals, and description thereof will be omitted.

[Embodiment 1] FIG. 1 is a view for explaining a display example of a radar coordinate system screen and a world standard coordinate system screen by the air traffic control radar system of the present invention. FIG. 1 (a) is a diagram showing the arrangement of the aircraft by projecting the aircraft to be displayed on a plane perpendicular to the ground surface. In contrast to this arrangement, the radar coordinate system screen shows the arrangement of the aircraft shown in FIG. Figure 1 on the coordinate system screen
It is displayed as shown in (c). In FIG. 1A, a reflector 7 that reflects radar radio waves and a GPS receiver 8 are installed at the same position in the reflection station 6. The reflection station 6 is installed, for example, within the range of a radar such as in an airport.

The first embodiment of the present invention, which is shown in FIG. 1 (b), is an air traffic control system in which the world standard coordinates of a GPS-compatible aircraft are converted into radar system coordinates and are superimposed and displayed on the radar coordinate system screen. A radar system for a vehicle will be described. On the radar coordinate system screen, the aircraft 1C and 1D have the same position 4C as the conventional one, respectively.
Displayed in 4D. For reflector stations, reflector 7
The radar measurement coordinates 9 and the world standard coordinates 10 reported from the GPS receiver can be acquired. These coordinates 9,
10 does not need to be displayed on the actual screen. Both coordinates 9, 1
Since 0 is measured by different methods such as radar and GPS, there is no guarantee of coincidence. The radar system for air traffic control uses the difference between the two coordinates 9 and 10 as correction information for a GPS compatible aircraft to convert world standard coordinates into radar system coordinates, and displays the GPS compatible aircraft in a radar coordinate system screen. To display. For example, GPS compatible aircraft 1A,
1B is displayed at positions 11A and 11B on the radar coordinate system screen.

The correction in the coordinate conversion described above is accurate G
Since the positioning value by PS is aligned with the radar positioning value with lower accuracy than this, the accuracy of the distance of the GPS compatible aircraft to the radar station is not improved, but it is displayed on the GPS compatible aircraft and the radar coordinate system screen. The accuracy of the relative distance with all the aircraft (GPS-compatible aircraft and non-GPS-compatible aircraft) is improved. Further, the aircraft 1B, which is located in the blind area and is not displayed on the conventional radar coordinate system screen, is also displayed superimposed on the screen.

The conversion method will be described in detail.

First, the notations used below will be described.
[Position P] and <Position P> represent world standard coordinates and radar system coordinates of the object P, respectively. In order to simplify the explanation, assuming that the earth is large enough for the range of the radar to ignore its curvature, an orthogonal coordinate system can be set with the radar station as the origin. Two axes that are horizontal to the ground surface of this orthogonal coordinate system, which is a substitute for the latitude and longitude coordinates of the world standard coordinates, are the x axis and the y axis, and the height direction is the z axis. The x, y and z components of the positioning value in this orthogonal coordinate system are represented by the subscripts x, y and h, respectively. The object P is [Position Px], [Position P on the world standard coordinate system screen.
The position is displayed using y]. <Position P> is represented by the azimuth angle φ and the distance r. If the azimuth angle is measured from the positive direction of the x-axis to the positive direction of the y-axis, the object P is displayed on the radar coordinate system screen as <Position P η> = r cos φ ··· (1) <Position P ξ> = rsin φ ······· (2) The position is displayed using <Position P η> and <Position P ξ>. In order to simplify the explanation, if the radar antenna, the reflector, and the GPS receiver are installed at almost the same height in the world standard coordinate system, the correction information is [correction amount x] = [positioning value 10x] − <positioning Value 9 η〉 ………… (3) [Correction amount y] ＝ [Positioning value 10y] − 〈Positioning value 9 ξ〉 ……… (4). (If the radar antenna and the reflector have different altitudes, the information in the height direction (elevation direction) of the reflector 7 can be supplemented with the altitude [positioning value 10h] of the GPS receiver.) Next The conversion of world standard coordinates [positioning value (5A)] measured by the GPS of the GPS compatible aircraft 1A will be described as an example. First,
Horizontal correction is performed by the following formula.

[Corrected position (12A) x] = [Positioned value (5A) x]-[Correction amount x] ... (5) [Corrected position (12A) y] = [Positioned value (5A) y]- [Correction amount y] ……… (6) Then, [correction position (12A)] is converted to the corresponding radar system coordinate <converted radar system coordinate (11A)> by the following formula.

[0031]

[Equation 1]

[Equation 2] By this conversion, the world standard coordinate [positioning value (5A)] is moved from the radar station in the direction of [correction position (12A)] ([correction position (12A)]
A) x] ² + [corrected position (12A) y] ² ) ^1/2 is converted to radar coordinates <transformed radar coordinates (11A)>. GP
The S-compatible aircraft 1A is positionally displayed on the radar coordinate system screen by the radar system coordinates.

The order of the correction calculation and the conversion calculation to the radar system coordinates may be reversed.

[Embodiment 2] Referring to FIG. 1 (c), the radar system coordinates of an SSR compliant and GPS non-compliant aircraft, which is a second embodiment of the present invention, are converted into world standard coordinates to obtain a world standard. A description will be given of a radar system for air traffic control which is displayed by being superimposed on a coordinate system screen. On the world standard coordinate system screen, the GPS aircraft 1A and 1B are displayed at the same positions 5A and 5B as before. The radar system for air traffic control can convert the radar system coordinates into world standard coordinates and display them together with the GPS compatible aircraft on the world standard coordinate system screen if the aircraft is not GPS compatible and is SSR compatible. For example, SS
The aircraft 1C that is R-compatible and non-GPS-compatible is displayed at position 13C on the world standard coordinate system screen. Since this coordinate conversion uses the correction information to correct the deviation between the radar system and the GPS system, the relative distance between the GPS non-compliant aircraft and another GPS compatible aircraft displayed on the screen of the world standard coordinate system. The accuracy of is good.

Radar measurement coordinates of aircraft 1C <positioning value (4
The conversion from C)> to world standard coordinates [transformation world standard coordinates (13C)] will be specifically described as an example. When the world standard coordinate system is represented by the orthogonal coordinates, the latitude and longitude of the world standard coordinate system are associated with the x and y components of the Cartesian coordinates. First, <Positioning value (4C)> is obtained by SSR using the following formula.
The altitude of C [positioning value Ch] is used to convert to [pre-correction position (14C)].

[0035]

(Equation 3)

(Equation 4) Next, using the correction information defined in the first embodiment, the following correction is performed so as to suppress the deviation between the radar system and the GPS system.

[Converted world standard coordinates (13C) x] = [Pre-correction position (14C) x] + [Correction amount x] ……… (11) [Converted world standard coordinates (13C) y] = [Pre-correction position (14C) y] + [correction amount y] ... (12) The GPS non-compliant aircraft 1C is displayed on the world standard coordinate system screen by this world standard coordinate.

The order of the correction calculation and the conversion calculation to the radar system coordinates may be reversed.

[Third Embodiment] FIG. 2 is a block diagram of a display device of an air traffic control radar system according to a third embodiment of the present invention. The data processing device 20 of the present display device inputs the positioning value 21 of the aircraft by the radar system and the positioning value 22 of the aircraft by GPS, and displays the processing result on the display 23. The data processing device 20 provides six processing modes. The user selects and uses the processing mode. Regarding the mode selection, there are a method of providing a panel switch and command input means on the display side, and a method of setting by command input on the data processing device 20 side. Further, as the processing method in the data processing device 20 when selecting on the display side, there is a method of processing only the mode designated by these switches, and only the data of the mode appropriately selected by performing the processing of all modes. Is output to the display.

3 to 8 are process flow charts of the respective processing modes.

FIG. 3 shows a mode in which the aircraft is displayed on the display in radar system coordinates using only radar positioning values. That is, at this time, the display functions as a radar coordinate system screen. The radar signal processing 30 performs basic processing on the radar signal such as elimination of clutter which is an unnecessary reflection signal and detection of a target signal from noise. The tracking / correlation process 31 performs a correlation process between a plurality of radar scans, removes residual clutter, and determines the time transition state of the target aircraft.

FIG. 4 shows a mode in which the aircraft position obtained from the GPS positioning value is displayed on the radar coordinate system screen together with other aircraft positions based on the radar positioning value. The radar system coordinate processing 32 is performed by the radar system / GPS described in the first embodiment.
This is a process of converting the world standard coordinates into radar system coordinates while correcting the difference of. The superposition processing 33 is performed by the radar positioning value and the GPS.
It is a process of superimposing the positioning value and generating one video output. In this process, for an aircraft that can obtain both the radar positioning value and the GPS positioning value, the position display is performed using only the GPS positioning value. Further, the display symbol for displaying the radar positioning value and the display symbol for displaying the GPS positioning value with different shapes are used so that the user can distinguish them.

FIG. 5 shows a radar coordinate system screen display mode for improving accuracy and reliability by using both radar positioning values and GPS positioning values for separating and identifying a plurality of target aircraft in the tracking / correlation processing 31. GPS positioning values are coordinated by radar system 3
It is used after applying 2. Further, when using both positioning values, it is necessary to consider the difference in the data communication time until each positioning value is transmitted to the radar station in order to ensure accuracy. Here, for an aircraft that can obtain only one of the two positioning values, such as a GPS non-compliant aircraft or a GPS compatible aircraft flying in a radar blind area, the tracking / correlation processing 31 is performed using only one of them.

FIG. 6 shows a mode in which the aircraft is displayed on the display in world standard coordinates using only GPS positioning values. That is, at this time, the display functions as a world standard coordinate system screen. Tracking / correlation processing 31 is performed by GPS.
The process of determining the time transition state of the target aircraft from the positioning value is performed.

FIG. 7 shows a mode in which the aircraft position obtained from the radar positioning value is displayed on the screen of the world standard coordinate system together with other aircraft positions based on the GPS positioning value. The world standard coordinate processing 34 is the same as the radar system / GP described in the second embodiment.
This is a process of converting the radar system coordinates into world standard coordinates while correcting the difference in S. The superimposing process 33 is a process having the same function as in FIG. 4, and the display symbols of the radar positioning value / GPS positioning value also use different shapes so that the user can distinguish them.

FIG. 8 shows a world standard coordinate system screen display mode for improving accuracy and reliability by using both radar positioning values and GPS positioning values for separating and identifying a plurality of target aircraft in the tracking / correlation processing 31. The radar positioning value is used after being subjected to world standard coordinate processing 34. Further, when using both positioning values, it is necessary to consider the difference in the data communication time until each positioning value is transmitted to the radar station in order to ensure accuracy. Here, for an aircraft that can obtain only one of the two positioning values, for example, an aircraft that is SSR compatible but not GPS compatible, or a GPS compatible aircraft that is flying in a radar blind area, use only one of them to perform tracking / correlation processing. 31.

The system described above as an air traffic control system can be applied not only to aircraft but also to ships, automobiles, etc. that move within a certain range.

[0047]

According to the radar system for air traffic control of claim 1 of the present invention, there is an effect that the GPS positioning value is converted into the radar system coordinates with high accuracy.

According to the air traffic control radar system of claim 2 of the present invention, the GPS-compatible aircraft is accurately superimposed and displayed on the radar-based coordinate display device that displays the aircraft by the radar measurement coordinates. The effect of improving the accuracy of relative distances to all other aircraft displayed on the radar coordinate system screen, and even if the aircraft is located in the radar blind area, it is displayed on the radar coordinate system screen if it is a GPS compatible aircraft. There is an effect.

According to the radar system for air traffic control of claim 3 of the present invention, the tracking processing accuracy for the GPS-compatible aircraft is the world standard coordinates measured by the GPS receiver provided in the reflection station and the radar measurement coordinates of the reflection station. There is an effect of improving by comparing the converted radar system coordinates corrected by using the difference between and with the radar measurement coordinates.

According to the air traffic control radar system of claim 4 of the present invention, the SSR compatible aircraft among the GPS non-compliant aircraft is accurately superimposed on the world standard coordinate display device in which the aircraft is displayed by highly accurate GPS measurement coordinates. Is displayed as
This has the effect of complementing the aircraft to be displayed.

As described above, according to the present invention, the accuracy of aircraft position management of the air traffic control radar system is improved,
It has the effect of contributing to the safety of today's developed air traffic.

[Brief description of drawings]

FIG. 1 is a plan view illustrating a configuration of a radar system for air traffic control according to the present invention and a radar coordinate system screen and a world standard coordinate system screen thereof.

FIG. 2 is a block diagram of a display device of an air traffic control radar system according to a third embodiment of the present invention.

FIG. 3 is a processing flowchart of the display device according to the third embodiment of the present invention.

FIG. 4 is a processing flowchart of the display device according to the third embodiment of the present invention.

FIG. 5 is a processing flowchart of the display device according to the third embodiment of the present invention.

FIG. 6 is a processing flowchart of the display device according to the third embodiment of the present invention.

FIG. 7 is a processing flowchart of the display device according to the third embodiment of the present invention.

FIG. 8 is a processing flowchart of the display device according to the third embodiment of the present invention.

FIG. 9 is a plan view illustrating display examples of a radar system coordinate display device by a conventional air traffic control radar system and a world standard coordinate display device by GPS.

[Explanation of symbols]

1A, 1B, 1C, 1D Aircraft, 2 radar stations, 3
GPS satellites, 4A, 4C, 4D Aircraft radar measurement coordinates, 5A, 5B Aircraft GPS global standard coordinates, 6 reflection stations, 7 reflectors, 9 reflection station radar measurement coordinates, 10 reflection station GPS global standard coordinates ,
11A, 11B Converted radar system coordinates of aircraft, 13C
Conversion of aircraft World standard coordinates, 20 Data processing device, 3
1 tracking / correlation processing, 32 radar system coordinate processing, 34
World standard coordinate processing.

Claims (4)

[Claims] 1. An air traffic control radar system having means for emitting a radar radio wave from a radar station to measure two-dimensional radar system coordinates of a distance and a direction of an aircraft in flight, the radar system having a reflection station, The reflection station has a reflector that reflects radar radio waves from the radar station, and a GPS receiver. The radar station is notified by a GPS-compatible aircraft equipped with the GPS receiver and is measured by the GPS receiver. And a means for receiving the world standard coordinates of the aircraft, wherein the world standard coordinates of the GPS compatible aircraft are converted into conversion radar system coordinates in the radar coordinate system, and in the conversion, the latitude and longitude of the world standard coordinates before conversion are used. Either one of the converted radar system coordinates is the GP of the reflection station.
An air traffic control radar system characterized by being corrected by using a difference between world standard coordinates measured by an S receiver and radar measurement coordinates of a reflection station. 2. The radar station according to claim 1, wherein the radar station has a radar system coordinate display device for displaying the radar measurement coordinates measured by the radar, and the GPS-compatible aircraft is a radar system coordinate display device using converted radar system coordinates. A GPS system that is not compliant with GPS is displayed on the radar coordinate display device according to radar measurement coordinates. 3. The radar system for air traffic control according to claim 1, wherein the coordinated radar system coordinate and the radar measurement coordinate of the GPS compatible aircraft are collated to perform tracking processing of the aircraft. 4. An air traffic control radar system having means for emitting two radio waves from a radar station to measure two-dimensional radar system coordinates of distance and direction of an aircraft in flight, the radar system having a reflection station, The reflection station has a reflector that reflects radar radio waves from the radar station, and a GPS receiver. The radar station is notified by a GPS-compatible aircraft equipped with the GPS receiver and is measured by the GPS receiver. And a world standard coordinate display device for displaying the position of a GPS-compatible aircraft by the world standard coordinates consisting of altitude and longitude and latitude. Converting radar measurement coordinates of an SSR-capable aircraft equipped with a surveillance radar transponder in the world standard coordinate system using the altitude reported by the secondary surveillance radar transponder Converted to latitude, in the conversion, one of the radar measurement coordinates of the aircraft before conversion and the conversion longitude and latitude is the world standard coordinates measured by the GPS receiver of the reflection station and the radar measurement coordinates of the reflection station. The radar system for air traffic control is characterized in that the SSR-compatible aircraft is position-displayed on the world standard coordinate display device according to the converted latitude and longitude after being corrected by using the difference between and.