JP2002221571A - Receiver and ssr device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple-structured receiver consisting of a small number of hardware units capable of specifying the azimuth and distance of a response pulse highly precisely, and an SSR(Secondary Surveillance Radar) device using the same. SOLUTION: A standard counter 16 counts a standard clock from an oscillator 15 with one rotation of an antenna as one cycle. An azimuth value/distance value converting part 17 converts the counter value of the standard counter 16 to the distance value of the response pulse using the distance setting value set in a distance setting value table 18, and converts the counter value of the standard counter 11 to the azimuth value of the response pulse using the azimuth setting value set in an azimuth setting value table 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving device used in, for example, an air traffic control system and an SS using the same.
R (Secondary Surveillance Radar) device.

[0002]

2. Description of the Related Art Conventionally, an SSR device has been known as an air traffic control radar used in an air traffic control system. As shown in FIG. 6A, this SSR device processes a response signal returned from a transponder (radar signal response device) mounted on an aircraft 103 in response to an inquiry signal from a ground radar device 102 having an antenna 101. To obtain the position and identification information of the aircraft.

In a system using a conventional SSR device, a question signal is transmitted to all aircraft in a lump, and all the aircraft respond to the query signal. , Referred to as a batch transaction). In this system, all aircraft receiving the interrogation signal respond at the same time. Therefore, when the air traffic volume increases, the response signals interfere with each other and information is lost. On the other hand, aircraft receiving interrogation signals from a plurality of SSR devices return a response each time, so that excessive interrogation and response are required for both the ground radar device and the transponder. Necessary actions cannot be taken.

Therefore, in recent years, an individual question / individual response (hereinafter, referred to as an individual inquiry) in which an individual inquiry is made to an aircraft using an address uniquely assigned to each aircraft, and only the inquired aircraft individually transmits a response signal. SSR devices that perform “individual transactions” have been developed.
Thereby, the problem due to the interference of the response signals is improved, and highly reliable monitoring is enabled. In this case, in order to monitor an aircraft equipped with a transponder that cannot respond to an individual question, as shown in FIG. 7, a batch transaction (all calls) A and an individual transaction (roll call) R alternately occur at an interrogation period T. This is done in splits.

[0005] In the SSR device, a question is scheduled in order to execute an individual transaction in an optimal state. In this case, it is known that scheduling the queries so that the responses are lined up in order from the aircraft farthest from the radar to the aircraft closer to the radar is most efficient. The scheduled query is transmitted by the query sending device to a transponder onboard the aircraft.

[0006] The antenna transmits an interrogation signal to the aircraft at each interrogation cycle while rotating, and receives a response signal from the aircraft. The received response signal is sent to the receiving device. A pulse encoder is attached to the antenna,
An azimuth change pulse (corresponding to the angle signal ACP) corresponding to the rotation angle of the antenna is sent to the receiving device by the pulse encoder.

FIG. 8 shows the configuration of such a conventional receiving apparatus. This receiving apparatus specifies the direction of a response pulse and the distance between an antenna and an aircraft based on a received response signal (hereinafter, referred to as a response pulse), and includes a direction counter 11, an oscillator 12, a distance counter 13, and pulse information. It is composed of an addition unit 14a. The oscillator 12 is 1/1
It has 6,1 / 32,1 / 64 resolution.

As shown in FIG. 6B, the azimuth counter 11 determines that the rotation angle of the antenna 101 is 0 degree (for example, north is 0 degree).
Degree. Azimuth reset pulse (ARP) at the time of)
To reset the azimuth counter value, count the angle signal ACP from the antenna 101 when the rotation angle of the antenna 101 when the response pulse is received is θ degrees, and output the azimuth counter value to the pulse information adding unit 14a.
From this azimuth counter value, the azimuth of the response pulse is specified and the azimuth resolution is obtained.

The distance counter 13 starts counting the clock of the oscillator 12 from the time when the interrogation signal is transmitted, sets the counter value when the response pulse is received as the distance counter value, and sets the distance counter value when the next interrogation signal is transmitted. The process of resetting the value is repeated for each interrogation period (time from the time when the interrogation signal is transmitted to the time when the next interrogation signal is transmitted).
This distance counter value is output to the pulse information adding unit 14a. The distance of the response pulse is specified from the distance counter value, and the distance resolution amount is obtained. That is, the distance from the antenna to the aircraft is obtained based on the time when the interrogation signal is transmitted and the time when the response pulse is received.
The pulse information adding unit 14a adds a bearing counter value and a distance counter value to the response pulse and outputs the response pulse as a response message.

[0010]

However, the conventional receiving apparatus shown in FIG. 8 cannot cope with the individual management of the response pulse (the above-mentioned individual response management). For this reason, as shown in FIG. 9, a receiving device having a function of individually managing response pulses is used. This receiving apparatus has an azimuth counter 11, an oscillator 12, a distance counter 13, 16 MHz
An oscillator 15 that generates a clock such as a clock, a reference counter 16 that counts a clock from the oscillator 15 and outputs a reference counter value with one rotation of the antenna as one cycle, And outputs a response message as a response message.

However, in this receiving apparatus, FIG.
As shown in (1), in order to specify the response pulse, it is necessary to synchronize the above three counter operations with the azimuth reset pulse ARP. That is, complicated timing synchronization processing had to be performed. Further, in order to increase the accuracy of the resolution amount for each of the direction and the distance of the response pulse, it is necessary to increase the accuracy of the direction counter and the distance counter. Accordingly, the amount of hardware increases. In addition, a distance counter, a direction counter, two oscillators, and a reference counter must be provided, which complicates the configuration.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and it is possible to specify the direction and distance of a response pulse with high accuracy, and furthermore, a receiving apparatus having a simple configuration with a small amount of hardware. And an SSR device using the same.

[0013]

According to the present invention, there is provided a receiving apparatus for receiving a response signal returned from an aircraft in response to an interrogation signal transmitted from a rotating antenna. An oscillator for generating a reference clock; a reference counter for counting a reference clock from the oscillator with one rotation of the antenna as one cycle; a counter value of the reference counter indicating an azimuth value indicating an azimuth of the response signal; And a conversion means for converting the distance into a distance value representing the distance between the aircraft.

According to this receiving apparatus, when the reference counter counts the reference clock from the oscillator with one rotation of the antenna as one cycle, the conversion means converts the counter value of the reference counter into an azimuth value indicating the azimuth of the response signal, the antenna and Since it is converted to a distance value representing the distance between aircraft, it is not necessary to use an azimuth counter, a distance counter or an oscillator for the distance counter, and only one high-precision oscillator and a reference counter are used. And the distance can be specified with high accuracy, and the receiving apparatus can be configured with simple and small hardware.

Further, the SSR apparatus of the present invention has a management unit for scheduling a transmission timing of a query, a query transmission device for transmitting a query signal in accordance with the transmission timing scheduled by the management unit, and a transmission unit for transmitting a query signal from a rotating antenna. A receiving device that receives a response signal returned from an aircraft in response to the question signal, and a question response processing unit that processes a response signal received by the receiving device and sends a question response to the management unit, The receiving device includes: an oscillator that generates a reference clock; a reference counter that counts a reference clock from the oscillator with one rotation of the antenna as one cycle; an azimuth value indicating the azimuth of the response signal; Conversion means for converting the distance between the antenna and the aircraft into a distance value representing a distance between the antenna and the aircraft.

According to this SSR device, similarly to the above-described receiving device, the direction and the distance of the response pulse can be specified with high accuracy, and the SSR device can be configured with simple and small hardware.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a receiver according to an embodiment of the present invention and an SSR device using the same will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an SSR device according to an embodiment of the present invention. This SSR device includes an antenna 1, a circulator 2, a transmitter 3, a receiver (corresponding to the receiving device of the present invention) 4, a question sending device 5, an individual question response processing unit 6, a collective question response processing unit 7, and a management unit 8. It is composed of

The question sending device 5 generates a question signal composed of a transmission pulse for each query cycle (transmission pulse cycle) based on the query data from the management unit 8. The transmitter 3 transmits the interrogation signal generated by the interrogation device 5 to the antenna 1 via the circulator 2. The antenna 1 transmits an interrogation signal to, for example, a transponder mounted on the aircraft 103 shown in FIG. 6 for each interrogation period while rotating at a fixed period (for example, 4 seconds). Further, the question sending device 5 generates a control signal and supplies the control signal to the individual question response processing unit 6.

The receiver 4 receives a response pulse from a transponder mounted on the aircraft 103 via the antenna 1 and the circulator 2, adds a reference counter value of a reference counter to the response pulse, and uses this as a response message. Output to each of the individual question response processing section 6 and the collective question response processing section 7. Details of the receiver 4 will be described later.

The individual question response processing section 6 processes a response message to the individual question received from the transponder mounted on the aircraft 103 via the antenna 1, the circulator 2 and the receiver 4, and processes the individual question response message. Generate. At this time, the individual question response processing unit 6
By referring to the control signal from the question sending device 5,
It is determined whether it is a response to the individual question sent from the question sending device 5. The individual question response message generated by the individual question response processing unit 6 is sent to the management unit 8.

The collective question response processing section 7 performs signal processing on a collective question response message received from the transponder mounted on the aircraft 103 via the antenna 1, the circulator 2 and the receiver 4, and generates a collective question response message. Generate. The collective question response message generated by the collective question response processing unit 7 is sent to the management unit 8.

The management unit 8 performs scheduling of the question sending timing in consideration of the individual question response message from the individual question response processing unit 6 and the collective question response message from the collective question response processing unit 7. Then, the question data generated by this scheduling is sent to the question sending device 5.

The management section 8 generates a query period start trigger signal for starting the operation of the individual transaction R and sends it to the question sending device 5. Thereby, the question sending device 5 starts the individual transaction R.

Next, the operation of the SSR device configured as described above will be described. As shown in FIG. 7, the query sending device 5 executes a plurality of (for example, four) transactions including a batch transaction A and an individual transaction R during one scan (one rotation) of the antenna 1. You.

First, in the batch transaction A, all aircraft equipped with transponders that cannot respond to the individual question return a response pulse to the batch question from the question sending device 5. The response pulse includes the position and identification information of the aircraft. This response pulse is input to the collective question response processing unit 7 as a response message via the antenna 1, the circulator 2, and the receiver 4. The collective question response processing unit 7 generates a collective question response message based on the response message and sends it to the management unit 8.

Next, in the individual transaction R, in response to the individual query from the question sending device 5 specifying an address uniquely assigned to each aircraft, only the aircraft inquired individually transmit a response pulse. The response pulse includes the position and identification information of the aircraft. The response pulse is input to the individual question response processing unit 6 as a response message via the antenna 1, the circulator 2, and the receiver 4. The individual question response processing unit 6 generates an individual question response message based on the response message and sends it to the management unit 8.

In the individual transaction R, the operations of the individual inquiry and the individual response are sequentially performed for each aircraft in accordance with the inquiry signal from the inquiry sending device 5. That is, at time t0
Now, individual transaction I for the first aircraft
0, at time t1, an individual transaction I1 for the second aircraft is performed at time t2, and at time t2, an individual transaction I2 for the third aircraft is sequentially performed, and a response message returned from each aircraft is supplied to the management unit 8.

The management unit 8 sets the next individual transaction R
In order to perform the above, based on the response message from each aircraft, the queries are scheduled such that the responses are arranged in order from the aircraft farther from the SSR device toward the closer aircraft. The question data generated by this scheduling is sent to the question sending device 5. Then, it is used in the next individual transaction R. Hereinafter, the same operation is repeated.

As described above, according to this SSR apparatus,
A batch transaction is performed for an aircraft equipped with a transponder that cannot respond to an individual question, and an individual transaction is performed for an aircraft equipped with a transponder capable of responding to an individual question, whereby the position and identification information are recognized. Therefore, it is possible to cope with any aircraft, and it is possible to avoid interference between response pulses caused by all aircraft responding to a query all at once.

Next, details of the receiver will be described. As shown in FIG. 2, the receiver 4 includes an oscillator 15, a reference counter 16, a pulse information adding unit 14, and an azimuth / distance value converter (corresponding to the converter of the present invention) 17. .

The oscillator 15 generates a high-precision reference clock of 16 MHz or the like. The reference counter 16 resets a counter value by inputting an azimuth reset pulse (ARP) when the rotation angle of the antenna 1 is 0 degree (for example, north is 0 degree), and the oscillator 15 outputs one rotation of the antenna 1 as one cycle. Is counted. The pulse information adding unit 14 adds the counter value of the reference counter 16 to a response pulse from the antenna 1 to generate pulse information. The azimuth value / distance value conversion unit 17 converts the counter value of the reference counter 16 in the pulse information of the pulse information addition unit 14 into an azimuth value indicating the azimuth of the response pulse and a distance value indicating the distance between the antenna 1 and the aircraft. Convert and output as response message.

The azimuth value / distance value conversion unit 17 includes the antenna 1
And a direction setting value table 19 that sets a distance setting value corresponding to an angle signal ACP representing the rotation angle of the inquiry signal and a distance setting value corresponding to a transmission cycle of the interrogation signal. The distance setting value table 18 and the azimuth setting value table 19 are provided on a recording medium such as a read-only memory and correspond to the setting means of the present invention.

The azimuth value / distance value converter 17 converts the counter value of the reference counter 16 at the time when the response pulse is received into the azimuth value of the response pulse based on the azimuth setting value set in the azimuth setting value table 19, Based on the distance setting value set in the distance setting value table 18, the counter value of the reference counter 16 at the time when the response pulse is received is converted into the response pulse distance value.

FIG. 3 is a diagram for explaining a process of converting the counter value of the reference counter provided in the receiving device into a distance value corresponding to the distance counter and an azimuth value corresponding to the azimuth counter. In FIG. 3, the vertical axis represents the value of each counter, and the horizontal axis represents time. In FIG. 3, the maximum counter value of the reference counter 16 in one scan of the antenna 1 is CT
It is 1max. The maximum counter value of the distance counter in one scan of the antenna 1 is CT2max, and this value is set as the distance setting value. The maximum counter value of the direction counter in one scan of the antenna 1 is CT3max, and this value is set as the direction setting value.

Next, the operation of the thus configured receiver 4 according to the embodiment of the present invention will be described. The operation when an individual transaction is performed will be described below with reference to FIGS.

First, the antenna 1 is rotated once (one scan).
Meanwhile, in the individual transaction R, the operation of the individual inquiry and the individual response is sequentially performed for each aircraft in accordance with the inquiry signal from the inquiry sending device 5. That is, at time t0
Now, individual transaction I for the first aircraft
0, at time t1, an individual transaction I1 for the second aircraft is performed at time t2, and at time t2, an individual transaction I2 for the third aircraft is sequentially performed, and the receiver 4 receives a response pulse returned from each aircraft.

In the receiver 4, the reference counter 16 starts counting upon input of the azimuth reset pulse ARP, and transmits an interrogation signal to the second aircraft at time t1, for example, and is returned from the second aircraft. Assume that a response pulse is received at time t3. And the reference counter 16
Outputs the counter value CT1 at time t3, and the pulse information adding unit 14 adds the counter value CT1 to the response pulse and outputs the azimuth value
Output to the distance value converter 17.

The azimuth value / distance value conversion unit 17 uses the azimuth setting value CT3max set in the azimuth setting value table 19 and calculates the counter value CT1 of the reference counter 16 from the pulse information adding unit 14 according to equation (1). Is converted into the azimuth value CT3 of the response pulse.

CT3 = CT1 * CT3max / CT1max (1) That is, by executing the proportional calculation from the counter value CT1 of the reference counter 16, the azimuth value of the response pulse can be obtained.

The azimuth value / distance value conversion unit 17 calculates the distance set value CT2ma set in the distance set value table 18.
Using x, the counter value CT1 of the reference counter 11 from the pulse information adding unit 14 is converted into the distance value CT2 of the response pulse by the equation (2).

CT2 = CT1−CT4 (2) That is, the response pulse distance value CT2 is a counter signal CT1 of the reference counter 16 at the time t3 when the response pulse is received, and an inquiry signal corresponding to the response pulse. It can be obtained from the difference between the counter value CT4 of the reference counter 16 at time t1.

FIG. 4 is a view for explaining a specific example of a process for converting the counter value of the reference counter provided in the receiving device into a distance value corresponding to the distance counter and an azimuth value corresponding to the azimuth counter.

In FIG. 4, the horizontal axis represents the counter value of the reference counter 16, and the maximum value is FFFFh (CT1max).
). It is assumed that the counter value of the reference counter 16 is 100h at time t1 and 200h at time t2. It is assumed that a period from time t1 to time t2 is a transmission pulse period (interrogation period) T, and a response pulse to the interrogation signal transmitted at time t1 is received at time t3. In this example, the distance value of the response pulse is 80h. The azimuth value of the response pulse can be obtained by the above (2).

As described above, the receiving apparatus and the S
According to the SR device, when the reference counter 16 counts the reference clock from the oscillator 15 with one rotation of the antenna as one cycle, the azimuth value / distance value converter 17 converts the distance setting value set in the distance setting value table 18 into the distance setting value. To convert the counter value of the reference counter 11 into a distance value of the response pulse,
Using the azimuth set value set in the azimuth set value table 19, the counter value of the reference counter 11 is converted into the azimuth value of the response pulse. Therefore, it is not necessary to use the azimuth counter 11, the distance counter 13, and the oscillator 12 for the distance counter, and the azimuth and distance of the response pulse can be determined with high accuracy only by using one high-accuracy oscillator 15 and the reference counter 16. The receiving apparatus can be specified, and the receiving apparatus can be configured with simple and small hardware. Further, since the azimuth counter 11 and the distance counter 13 are not used, complicated timing synchronization processing of three counters as in the related art is not required.

[0046]

As described in detail above, according to the present invention,
It is possible to provide a receiving apparatus having a simple configuration with a small amount of hardware and an SSR apparatus using the same, which can specify the direction and distance of the response signal with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an SSR device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a receiving device according to the embodiment of the present invention.

FIG. 3 is a view for explaining a process of converting a counter value of a reference counter provided in the receiving device into a distance value corresponding to a distance counter and an azimuth value corresponding to an azimuth counter.

FIG. 4 is a diagram illustrating a specific example of a process of converting a counter value of a reference counter provided in the receiving device into a distance value corresponding to a distance counter and an azimuth value corresponding to an azimuth counter.

FIG. 5 is a diagram showing the contents of a pulse information adding unit provided in the receiving device.

FIG. 6 is a diagram showing a configuration of a conventional SSR device.

FIG. 7 is a diagram illustrating the operation of a conventional SSR device.

FIG. 8 is a block diagram showing a configuration of a conventional receiving apparatus.

FIG. 9 is a block diagram showing the configuration of another example of a conventional receiving apparatus.

FIG. 10 is a timing chart illustrating the operation of another example of the conventional receiving apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Antenna, 2 ... Circulator 3 ... Transmitter, 4 ...
Receiver, 5: Question sending device, 6: Individual question response processing unit,
7: collective question-response processing unit, 8: management unit, 11: orientation counter, 12, 15: oscillator, 13: distance counter, 1
4, 14a, 14b: pulse information adding section, 16: reference counter, 17: azimuth value / distance value conversion section, 18: distance setting value table, 19: azimuth setting value table.

Claims (7)

[Claims] 1. A receiving device for receiving a response signal returned from an aircraft in response to an interrogation signal transmitted from a rotating antenna, comprising: an oscillator for generating a reference clock; and A reference counter that counts a reference clock from an oscillator; and a conversion unit that converts a counter value of the reference counter into an azimuth value indicating an azimuth of the response signal and a distance value indicating a distance between the antenna and the aircraft. A receiving device, characterized in that: 2. An azimuth setting value corresponding to an angle signal indicating a rotation angle of the antenna and a setting unit for setting a distance setting value corresponding to a transmission cycle of the interrogation signal; The counter value of the reference counter at the time when the response signal is received is converted into the azimuth value of the response signal based on the response signal, and the counter value of the reference counter at the time when the response signal is received based on the distance set value is used as the response 2. The receiving device according to claim 1, wherein the signal is converted into a distance value of a signal. 3. The distance value is obtained by a difference value between a counter value of the reference counter at a time when the response signal is received and a counter value of the reference counter at a time when the interrogation signal corresponding to the response signal is transmitted. 3. The receiving device according to claim 2, wherein said receiving device is determined. 4. A management unit for scheduling the transmission timing of a query, a query transmission device for transmitting a query signal in accordance with the transmission timing scheduled by the management unit, and a response to the query signal transmitted from a rotating antenna. A receiving device that receives a response signal returned from the aircraft; and a query response processing unit that performs signal processing on the response signal received by the receiving device and sends a query response to the management unit, wherein the receiving device sets a reference clock. An oscillator that is generated; a reference counter that counts a reference clock from the oscillator with one cycle of the antenna as one cycle; a counter value of the reference counter between an azimuth value indicating an azimuth of the response signal and the antenna and the aircraft. A conversion unit for converting the distance into a distance value representing a distance. 5. The question-and-answer processing unit, which performs signal processing on a response signal returned in response to a batch-question sent to all aircraft, and transmits to each of the aircraft. An individual question response processing unit that performs signal processing on a response signal returned in response to the individual question
The SSR device according to claim 4, comprising: 6. Setting means for setting an azimuth set value corresponding to an angle signal representing a rotation angle of the antenna and a distance set value corresponding to a transmission cycle of the interrogation signal, wherein the conversion means comprises: The counter value of the reference counter at the time when the response signal is received is converted into the azimuth value of the response signal based on the response signal, and the counter value of the reference counter at the time when the response signal is received based on the distance set value is used as the response The SSR apparatus according to claim 5, wherein the SSR apparatus converts the distance value into a signal distance value. 7. The distance value is obtained by a difference value between a counter value of the reference counter at a time when the response signal is received and a counter value of the reference counter at a time when the inquiry signal corresponding to the response signal is transmitted. 7. The SSR device according to claim 6, wherein the SSR device is determined.