JPH08278365A - Mode s secondary surveillance radar device - Google Patents

Abstract

PURPOSE: To increase data link communication capacity, relating to a secondary surveillance radar device (SSR mode S) having a mechanical rotation type antenna. CONSTITUTION: The transmission data from a inquiry management calculator 1 is converted into high-frequency signal by a transmitter 2 and transmitted from a mechanical rotation type antenna 3 having main beam and sub-beam toward an aircraft. The position of the aircraft is predicted in advance by the inquiry management calculator 1, and, usually transmission is performed at the timing when a target aircraft is present within the main beam of the mechanical rotation type antenna 3, however, when communication is not finished in the main beam and further the inquiry management calculator 1 decides that switching over to sub-beam will increase data link communication capacity, a selector switch 4 switches the output of the transmitter from the main beam over to the sub-beam, based on the switching signal from the inquiry management calculator 1. The response signal from the aircraft is, after received by the then beam at the mechanical rotation type antenna, inputted in the receiver 5 for amplifying, and then converted into digital data by a signal processing device 6, and then inputted into the inquiry management calculator 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the data link capacity of a secondary surveillance radar device (SSR mode S) having a data link function.

[0002]

2. Description of the Related Art A secondary surveillance radar device (SSR mode S) having a conventional mechanical rotating antenna has generally used one antenna beam for asking a surveillance question or a data link question to perform an inquiry and a response. . That is, a question for monitoring is transmitted to the aircraft at a timing at which it is predicted that the aircraft will enter the antenna beam due to antenna rotation, and a question response for data link communication is repeated in response to the inquiry.
During this time, the antenna is rotating at a constant speed, so if the target aircraft goes out of the antenna beam, communication will be interrupted, the antenna will make one revolution, and the target aircraft will move back into the antenna beam. The method is that you have to wait until you enter. Further, when there are a plurality of aircraft in the antenna beam, the question and answer are made to each aircraft at an equal rate among the aircraft according to the priority of the communication content.

[0003]

As described above, the secondary surveillance radar device (SS) having the conventional mechanical rotating antenna is used.
In R mode S), since the monitoring and data link communication can be performed only while the aircraft is within one antenna beam, there is a problem that the communication amount per aircraft is reduced when the aircraft are concentrated in the same direction. was there.

In view of the above problems of the prior art, an object of the present invention is to switch the direction of the beam of the mechanical rotating antenna between the main beam and the sub beam, thereby completing the communication with the main beam. If not,
It is an object of the present invention to provide an SSR device that allows the remaining communication to be completed by the sub-beam after the main beam has passed, and can complete the communication without waiting for one antenna rotation time as much as possible.

[0005]

The present invention has the following means for achieving the above object. That is, the present invention is a mode S secondary surveillance radar device having the following configuration. (A) A mechanical rotating antenna that can be switched to either the main beam or one or more sub-beams having an azimuth that is deviated from the azimuth of the main beam in the direction opposite to the rotation direction by an angle that is determined. The aircraft position data received for each rotational scan of the antenna is stored in a monitoring data file, the data link communication volume with each aircraft is managed, and the individual aircraft are queried in any order as the antenna rotates. A question management computer that plans the flight and outputs the transmission control signal, and outputs the switching signal between the main beam and the sub beam so that the data link capacity for the aircraft in the main beam coverage area and the aircraft in the sub beam coverage area is maximized. (C) Question management transmitter that transmits the transmission data based on the transmission control signal from the computer to the mechanical rotary antenna (D) Question management device Switch that switches between the main beam and sub-beam of the mechanical rotary antenna according to the switching signal from the machine (e) Receiver that processes the signal from the mechanical rotary antenna (f) Converts the received signal into digital information Signal processing device for sending to question management computer

[0006]

The operation of the secondary surveillance radar device of the present invention will be described below. The antenna device of this device can change the beam direction from the main beam by a predetermined angle in the direction opposite to the antenna rotation direction. This is the sub beam.
Therefore, if the data link communication is not completed while the aircraft is in the coverage area of the main beam, it is possible to continue the data link communication with the aircraft that has entered the sub beam coverage area by switching to the sub beam. .

If only one sub-beam is switched, and if the data link communication is not completed within the sub-beam coverage area, there is no choice but to wait until the antenna makes another revolution. When it is possible to switch between the two sub-beams, it is possible to enter the sub-beam coverage area and continue the communication to complete the communication, which can be completed without waiting for a time close to one antenna rotation.

When there is no other aircraft in the airspace where the antenna is rotating and scanning, by switching to the sub-beam as described above, it is not necessary to wait until the antenna makes one revolution and the beam crosses the aircraft again. The number of cases increases and the communication efficiency improves.

On the other hand, when another aircraft exists in the air space in which the antenna is rotationally scanned, even if the sub-beam is switched for the previous aircraft, the sub-beam is switched to the main beam and the interrogation signal is sent. If the data link communication can be completed within the main beam coverage area, or if it can be completed by switching to the sub beam even if the data link communication cannot be completed within the main beam coverage area, it must be switched to the sub beam for the previous aircraft. I won't. These judgments are made by the question management computer.

The question management computer stores the aircraft position data received and acquired for each rotational scan of the antenna in a monitoring data file, and manages how much communication with each aircraft should be performed. Therefore, it is possible to predict at what point in time, how many aircrafts and how much communication will be required as the antenna rotates. Therefore, it is determined whether switching to the sub beam will improve the efficiency of the data link communication as a whole, and when it is determined that the efficiency will be improved, a switching signal to the sub beam is sent to the changeover switch.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of a mode S secondary surveillance radar device of the present invention. Transmission data from the question management computer 1 is converted into a high frequency signal by the transmitter 2 and transmitted from the mechanical rotary antenna 3 having a main beam and a sub beam to the aircraft. The question management computer 1 predicts the position of the aircraft in advance, and normally transmits at the timing when the target aircraft exists within the main beam of the mechanical rotating antenna. The changeover switch 4 has a function of changing over which of the main beam and the sub beam the output from the transmitter is to be output based on the switching signal from the question management computer 1. The response signal from the aircraft is received by the beam of the mechanical rotary antenna that has been switched, is input to the receiver 5 and is amplified, and is then converted into digital data by the signal processing device 6 to be transmitted to the question management computer. 1
Is input to.

In the question management computer 1, an individual question period based on the current time (question period using an address for each machine)
And a batch interrogation period (a batch interrogation for all aircraft in the antenna beam without using individual addresses), and at least one position inquiry and communication request for each aircraft per revolution of the antenna. Ask data link questions according to.

At this time, the position interrogation is preferentially performed by the main beam having excellent azimuth accuracy of the antenna, and the data link interrogation is performed by the time of the remaining main beam and sub-beam within the individual interrogation period. I decided to.
Therefore, the horizontal beam width of the main beam is made narrower than the horizontal beam width of the sub beam.

If there are many communication messages to the aircraft in the current main beam and all data link transmissions cannot be performed within the current main beam time, the remaining communication messages are communicated at the timing of entering the sub beam. Become. However, since the individual interrogation time is shared by the main beam and the sub-beam and it is necessary to use it in time division, it is necessary to decide which one has priority.

FIG. 2 is a diagram for explaining an example of prediction judgment in the question management computer of the present invention. (A) of the figure shows that in the dual-beam antenna, the aircraft C exists in the main beam coverage area and the aircraft A exists in the sub-beam coverage area. In this state, if many data link communication messages to the aircraft A are left, after a certain time has passed from the antenna position of the dual beam antenna of (a) of the figure, that is, as shown in (b) of the figure, Predict the timing when the same aircraft C as in a) enters the sub-beam coverage area, and at that time total the number of data link communication messages with the aircraft that enter the main beam.

As a result, as shown in (b) of the figure, the aircraft D enters the main beam coverage area, and both the communication time with the aircraft D and the communication time with the aircraft C in the sub-beam can be within the beam time. For example, at the timing of (a) in the figure, communication with the aircraft C is postponed and communication with the aircraft A is prioritized. By doing so, the data link communication message to the aircraft A can be transmitted more quickly (with a difference in rotation time between the main beam and the sub beam without waiting for one antenna rotation time) than in the method of the present invention which does not use the sub beam. You can

To summarize the above, when there is an aircraft in which data link communication cannot be completed in the main beam coverage area in the sub-beam coverage area and another aircraft exists in the main beam coverage area. , Predicting aircraft density and data link capacity within the sub-beam coverage and within the main-beam coverage at the time the aircraft in the main-beam coverage enters the sub-beam coverage, both of which data-link communication can be completed within each beam coverage If so, defer the data link to the aircraft currently in the main beam coverage until the aircraft is in the sub beam coverage and output a beam switch signal to perform a data link with the aircraft currently in the sub beam coverage. That's what it means.

As the predicting process, it is also possible to further predict and aggregate the timing when the aircraft D enters the sub-beam and the number of data link communication messages of the aircraft entering the main beam at that time. The opportunity equalization of data link communication for aircraft in a wide range becomes possible. Considering that the data link communication message is generated at any time, the prediction of one scan or more is considered meaningless. In this embodiment, one sub-beam has been described, but it is also possible to use two or more sub-beams and use each sub-beam for data link communication.

[0019]

As described above, according to the present invention, in a mechanical rotary antenna, a sub-beam dedicated to a data link is provided, and a question management computer establishes a communication schedule for the present and the near future. By switching between the main beam and the sub-beams to perform data link communication when they are densely packed, there is an advantage that the data link capacity can be increased as compared with the conventional case where there is no sub-beam.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a mode S secondary surveillance radar device of the present invention.

FIG. 2 is a diagram illustrating an example of prediction judgment in the question management computer of the present invention.

[Explanation of symbols]

 1 Question management computer 2 Transmitter 3 Mechanical rotary antenna 4 Changeover switch 5 Receiver 6 Signal processing device

Claims (3)

[Claims] 1. A mode S secondary surveillance radar device having the following configuration. (A) A mechanical rotating antenna that can be switched to either the main beam or one or more sub-beams having an azimuth that is deviated from the azimuth of the main beam in the direction opposite to the rotation direction by an angle that is determined. The aircraft position data received for each rotational scan of the antenna is stored in a monitoring data file, the data link communication volume with each aircraft is managed, and the individual aircraft are queried in any order as the antenna rotates. A question management computer that plans the flight and outputs the transmission control signal, and outputs the switching signal between the main beam and the sub beam so that the data link capacity for the aircraft in the main beam coverage area and the aircraft in the sub beam coverage area is maximized. (C) Question management transmitter that transmits the transmission data based on the transmission control signal from the computer to the mechanical rotary antenna (D) Question management device Switch that switches between the main beam and sub-beam of the mechanical rotary antenna according to the switching signal from the machine (e) Receiver that processes the signal from the mechanical rotary antenna (f) Converts the received signal into digital information Signal processing device for sending to question management computer 2. The process by which the question management computer maximizes the data link capacity, there is an aircraft whose data link communication cannot be completed in the main beam coverage area during the sub beam coverage area, and the main beam Predicting aircraft density and data link capacity within the sub-beam coverage and within the main-beam coverage when the aircraft in the main-beam coverage enters the sub-beam coverage when other aircraft are present in the coverage, If both determine that the data link communication can be completed within each beam coverage area, the data link to the aircraft currently within the main beam coverage area is postponed until the aircraft is within the sub beam coverage area and is now within the sub beam coverage area. The mode S secondary surveillance radar according to claim 1, wherein a beam switching signal is output to perform a data link with an aircraft. apparatus. 3. The mode S secondary surveillance radar device according to claim 1, wherein the underwater beam width of the main beam of the mechanical rotating antenna is smaller than the beam width of the sub beam.