KR102501708B1 - Aircraft locating method using interrogator having time of transmission function - Google Patents

Abstract

The vehicle positioning method according to this embodiment includes: transmitting a first interrogation signal to the vehicle by an interrogator; detecting and receiving a response to the first interrogation signal transmitted by the vehicle transponder by a receiver; Transmitting the time to the central processing unit, transmitting the second interrogation signal to the vehicle by the interrogator, and detecting and receiving a response to the second interrogation signal transmitted by the transponder of the vehicle by the receiver The time from the time of transmitting the time to the central processing unit and the time from when the interrogation signals are transmitted to the time when the aircraft receives the interrogation signals, and from the time when the transponder transmits the response signal light to the interrogation signals, the receiver receives the response signals A step of determining the position of the aircraft using the sum of times up to a point in time is included.

Description

Flight object positioning method using an interrogator having transmission time function {AIRCRAFT LOCATING METHOD USING INTERROGATOR HAVING TIME OF TRANSMISSION FUNCTION}

The present technology relates to a method for locating an aircraft using an interrogator having a transmission time function.

The MLAT (Multilateration) method uses a hyperbola or hyperboloid localization method to output four signals to the transponder of an aircraft (in case of three, two-dimensional position calculation is possible). In the above receivers, it is common to obtain the position of an aircraft by measuring a time difference of arrival (TDOA) between them.

The receiver of the MLAT system precisely measures the signal provided by the aircraft and delivers the received precise time to the central processing unit. The receivers operate in synchronization to calculate a precise TDOA. Receivers receive time information from satellites such as GPS and GLONASS and operate in synchronization with each other.

TDOA, one of the MLAT position calculation methods, is affected by dilution of precision (DOP). In particular, when tracking the position of an aircraft moving outside the closed curve when the receiver is arranged forming a closed curve, a large position error appears. In order to improve the accuracy of MLAT, the DOP should be improved by properly arranging the receiver. However, in reality, there are difficulties due to receiver installation constraints (building, power supply, data communication, etc.).

One of the problems to be solved by the present embodiment is to provide a method capable of improving accuracy when detecting a position of a moving object.

The vehicle positioning method according to this embodiment includes: transmitting a first interrogation signal to the vehicle by an interrogator; detecting and receiving a response to the first interrogation signal transmitted by the vehicle transponder by a receiver; Transmitting the time to the central processing unit, transmitting the second interrogation signal to the vehicle by the interrogator, and detecting and receiving a response to the second interrogation signal transmitted by the transponder of the vehicle by the receiver The time from the time of transmitting the time to the central processing unit and the time from when the interrogation signals are transmitted to the time when the aircraft receives the interrogation signals, and from the time when the transponder transmits the response signal light to the interrogation signals, the receiver receives the response signals A step of determining the position of the aircraft using the sum of times up to a point in time is included.

According to one aspect of this embodiment, the method includes: prior to sending out the first interrogation signal, the central processing unit controls the interrogator to send out the first interrogation signal; and prior to sending out the second interrogation signal, The method further includes controlling the central processing unit to transmit a second interrogation signal to the interrogator.

According to one aspect of the present embodiment, the interrogator transmits a Time of Transmission (TOT) at which each interrogation signal was transmitted to the central processing unit after transmitting the first interrogation signal and the second interrogation signal.

According to one aspect of this embodiment, the sum of the times is the time from the time the interrogator transmits the first interrogation signal to the time the transponder receives the first interrogation signal, and the response of the transponder to the first interrogation signal. It includes the sum of the times from the time when the signal is transmitted to the time when the receiver receives the response signal for the first interrogation signal.

According to one aspect of this embodiment, the sum of the times is the time from the time the interrogator transmits the second interrogation signal to the time the transponder receives the second interrogation signal and the transponder sends a response signal to the second interrogation signal. It further includes the sum of the times from the time of transmission to the time when the receiver receives the response signal for the second interrogation signal.

According to one aspect of this embodiment, the first query is a Mode A or C signal.

According to one aspect of this embodiment, the response signal to the first query is transmitted 3 μsec after the transponder receives the P3 signal of Mode A or C.

According to one aspect of this embodiment, the second query is the Mode S signal.

According to one aspect of this embodiment, the response signal to the second query is transmitted 128 μsec after the transponder receives the P6 signal of the Mode S signal.

According to one aspect of this embodiment, the method is performed on a plurality of interrogators and a plurality of receivers.

According to this embodiment, the time from the time the interrogation signals are transmitted to the time the aircraft receives the interrogation signals, and the time from the time the transponder transmits response signals to the interrogation signals to the time the receiver receives the response signals Since the position of the aircraft is determined using the sum of , the advantage of being able to more precisely detect the track of the aircraft is provided.

1 is a block diagram showing the outline of an interrogator according to the present embodiment.
2 is a diagram illustrating an example of an interrogation signal transmitted by an interrogator.
3 is a block diagram showing an outline of a receiver according to this embodiment.
Figure 4 is a flow chart showing the outline of the vehicle positioning method according to the present embodiment.
5 is a view for explaining a method for determining the position of an aircraft (A).

Hereinafter, this embodiment will be described with reference to the accompanying drawings.

1 is a block diagram showing the outline of an interrogator 20 according to the present embodiment. The interrogator 20 according to the present embodiment includes: an interrogation signal providing unit 100 that forms an interrogation signal, a band conversion unit 200 that converts the interrogation signal into an RF band, and the power of the interrogation signal converted into an RF band and a power amplifier 300 that amplifies and outputs the amplified interrogation signal to an antenna for transmission.

The interrogation signal providing unit 100 forms an interrogation signal and provides it to the band conversion unit 200 . The interrogation signal is a digital signal and is converted into an analog signal by a digital-to-analog converter (DAC) 110 . The interrogation signal converted to analog has a frequency of an intermediate frequency (IF) band. For example, the mid-band interrogation signal has a frequency of 70 MHz.

The band conversion unit 200 up-converts the frequency of the interrogation signal having an intermediate band frequency to an RF band and provides the up-converted frequency to the power amplifier 300 . As an embodiment, the band conversion unit 200 includes the phase conversion unit 210 and converts the frequency of the interrogation signal having an intermediate frequency band into an RF band. For example, the interrogation signal converted to the RF band has a frequency of 1030 MHz.

The power amplifier 300 amplifies the interrogation signal converted to the RF band into desired power, and provides the power to the antenna for transmission. In one embodiment, the power amplifier 300 receives the interrogation signal of -3dbm, amplifies it to 54dbm, provides it to the antenna, and transmits it to the outside.

2 is a diagram illustrating an example of an interrogation signal transmitted by the interrogator 20. Referring to FIG. The interrogation signals transmitted by the interrogator 20 may include a first interrogation signal and a second interrogation signal, the first interrogation signal may be the MODE A and C signals, and the second interrogation signal may be the MODE S signal.

3 is a block diagram showing the outline of the receiver 10 according to this embodiment. Referring to FIG. 3, the MLAT receiver 10 according to this embodiment includes a precision clock generator 1000 that forms a precision clock in synchronization with a time signal provided by an artificial satellite, and a signal provided by a transponder to receive a base signal. An RF receiver 2000 that converts to a band, a signal processor 3000 that forms Time Of Arrival (TOA) information from a signal converted to baseband, and a packet containing TOA information to a central processing system (CPS) A message processing unit 4000 is included.

The MLAT receiver 10 according to this embodiment forms a precise clock synchronized with a time signal provided by an artificial satellite, receives a signal provided by a transponder, and converts the signal into a baseband. The MLAT receiver 10 forms Time Of Arrival (TOA) information from a signal converted to baseband and provides a packet including the TOA information to the central processing unit.

Referring to FIGS. 1 and 2 , the precision clock generator 1000 receives a time signal from an artificial satellite and forms a precision clock in synchronization therewith. In one embodiment, the artificial satellite is a GPS (Global Positioning System) satellite, and the time signal is a 1 PPS (Pulse Per Second) signal transmitted at a period of 1 second. In another embodiment, the satellite is a GLONASS satellite and the time signal is a time signal provided by the GLONASS satellite.

In one embodiment, the precision clock generator 1000 includes a local clock generator (not shown) that forms a local clock synchronized with a time signal provided by an artificial satellite, and a local clock having a frequency higher than that of the local clock. It includes a first clock forming unit (not shown) for forming a first clock. The local clock generator and the first clock generator may each include a phase locked loop (PLL).

When the phase and frequency of the local clock are synchronized with the time signal provided by the artificial satellite, the first clock generator included in the precision clock generator 1000 forms a first clock having a higher frequency than the local clock to form the RF receiver 2000. ) is provided. In one embodiment, the first clock has a frequency of 10 MHz.

The precision clock generator 1000 receives CA codes (Coarse Acquisition codes), P codes (Precise codes) and navigation messages provided by satellites, Coordinated Universal Time (UTC) information, altitude information of a receiver, National Marine Electronics Association (NMEA) information including location information of the receiver is formed and provided to the message processing unit 4000 .

The message processing unit 4000 initializes the signal processing unit 3000 when state information (time source state) changes. For example, the message processing unit 4000 updates the time information of the signal processing unit 3000 using UTC time information included in the provided NMEA information, and initializes a counter (not shown) for calculating TOA. The time information provided to the signal processing unit 3000 forms Time Of Day (TOD) information, which is information about the hour, minute, and second at which the signal provided by the transponder of the aircraft is received, and the time point at which the signal provided by the transponder is received. It is transmitted to the central processing unit (CPS, not shown) together with TOA information, which is information about.

As will be described below, the counter included in the signal processing unit receives a sampling clock and counts the number of sampling clock pulses to form TOA information, which is information about a time point at which a signal provided by a transponder is received. Also, the message processing unit 4000 may update its own time information using NMEA information.

The RF receiver 2000 receives an RF signal provided by an aircraft transponder or a reference monitoring transponder, and converts the RF signal into baseband. The RF receiver 2000 receives the Mode 3/A signal, Mode C signal, Mode S signal, and 1090ES signal provided by the aircraft transponder or the reference monitoring transponder (RMT), converts them into baseband, and converts them into the signal processing unit (3000 ) is provided. As an embodiment, the RF receiver 2000 includes a down conversion unit (not shown) that converts the received signal to baseband and an envelope that performs envelope detection on the baseband converted signal. A wave detector (not shown) may be included. For example, the envelope detector provides the formed envelope to the signal processing unit 3000 .

의 해상도를 가질 수 있다. The RF receiver 2000 receives the first clock formed by the precision clock generator 1000, forms a sampling clock (SCK) having a frequency higher than the frequency of the first clock, and provides it to the signal processor 3000. As an embodiment, the RF receiver 2000 may further include a sampling clock generator configured to receive the first clock and generate a sampling clock. For example, the sampling clock may be 100 MHz. The signal processing unit 3000 samples the baseband converted signal using the sampling clock SCK. When a preamble of a signal is provided as one input of the sampler, the preamble is received using the number of sampling clock cycles counted from the time when the counter (not shown) of the signal processing unit 3000 is reset. The time of arrival (TOA) is obtained. In one embodiment, the TOA data is

may have a resolution of

Figure 4 is a flow chart showing the outline of the vehicle positioning method according to the present embodiment. 5 is a view for explaining a method for determining the position of an aircraft (A). Referring to FIGS. 4 and 5 , the interrogator (ITX) 10 transmits a first interrogation signal to the air vehicle (S100). In one embodiment, the first interrogation signal I1 transmitted by the interrogator ITX may be, for example, a MODE AC signal. The interrogator ITX may transmit the first interrogation signal I1 and transmit the transmission time to the central processing unit (not shown). For example, the time transmitted by the interrogator ITX may be a signal having the same precision as the TOA data.

The transponder of the vehicle A receives the first interrogation signal I1 and transmits a response signal A1 to the first interrogation signal after a predetermined delay time of 3 μsec. A response signal to the first question signal may be broadcast to a plurality of receivers 10a, 10b, 10c, and 10d.

의 높은 정밀도록 측정된 시각이다.The receiver receives the response signal A1 to the first question signal and transmits the received time to the central processing unit (S200). As described above, the time at which the receiver receives the response signal A1 to the first interrogation signal is

It is the time measured with high precision of

Therefore, the time transmitted by the receiver is the time from the time the receiver transmits the first interrogation signal I1 to the time the transponder receives the first interrogation signal I1, and the time when the first interrogation signal is received. It may be time information corresponding to the sum of a delay time of 3 μsec and a time from when the transponder transmits the response signal A1 to the first interrogation signal to when the receiver receives the response signal A1. . Also, each of the plurality of receivers 10a, 10b, 10c, and 10d may transmit time information corresponding to the sum of times up to the time of receiving the response signal A1 to the central processing unit.

Subsequently, the interrogator (ITX) 10 transmits a second interrogation signal to the vehicle (S300). As an example, the second interrogation signal I2 transmitted by the interrogator ITX may be, for example, a MODE S signal. The interrogator ITX may transmit the second interrogation signal I2 and transmit the transmission time to the central processing unit (not shown). For example, the time transmitted by the interrogator ITX may be a signal having the same precision as the TOA data.

The transponder of the aircraft (A) receives the second interrogation signal (I2), and the transponder transmits a response signal (A2) to the second interrogation signal after a predetermined delay time of 128 μsec. A response signal to the second question signal may be broadcast to a plurality of receivers 10a, 10b, 10c, and 10d in the same manner.

의 높은 정밀도록 측정된 시각일 수 있다. The receiver receives the response signal A2 to the second question signal and transmits the received time to the central processing unit (S400). As described above, the time at which the receiver receives the response signal A2 to the second interrogation signal is similarly

It may be the time measured with high precision of .

Therefore, the time transmitted by the receiver to the central processing unit is the time from the time the receiver transmits the second interrogation signal I2 to the time the transponder receives the second interrogation signal I2 and the second interrogation signal A time corresponding to the sum of a predetermined delay time of 128 μsec from the time of reception and the time from the time the transponder transmits the response signal A2 to the second interrogation signal to the time the receiver receives the response signal A2 may be information. In addition, each of the plurality of receivers 20a, 20b, 20c, and 20d may transmit time information corresponding to the sum of times up to the time of receiving the response signal A2 to the central processing unit.

The central processing unit provided with time information measured with high precision determines the position of the aircraft using the provided sum of times (S500). In one embodiment, the central processing unit determines the time from when the first interrogation signal I1 is transmitted to the time when the transponder receives the first interrogation signal I1, and the response of the transponder to the first interrogation signal. The position of the aircraft A can be determined using a time corresponding to the sum of the times from the time when the signal A1 is transmitted to the time when the receiver receives the response signal A1.

In addition, the central processing unit determines the time from when the second interrogation signal I2 is transmitted to the time when the transponder receives the second interrogation signal I2, and the response signal A2 to the second interrogation signal from the transponder. ) can be used to determine the position of the vehicle (A) using a time corresponding to the sum of the times from the time of transmitting the receiver to the time of receiving the response signal (A2).

In the above-described embodiment, the first question signal and the second question signal exemplified the MODE A C signal and the MODE S signal, respectively. However, in another embodiment, the first interrogation signal and the second interrogation signal may be the MODE S signal and the MODE A C signal, respectively.

The transporter receiving the MODE S interrogation signal and the MODE A C interrogation signal transmits a response signal after a predetermined delay time as described above, but there may be a tolerance of ±10nsec. However, according to the present embodiment, since the sum of times is used, an error in the position of the aircraft due to tolerance can be reduced.

It has been described with reference to the embodiments shown in the drawings to aid understanding of the present invention, but this is an embodiment for implementation and is merely exemplary, and various modifications and equivalents from those of ordinary skill in the art It will be appreciated that other embodiments are possible. Therefore, the true technical scope of protection of the present invention will be defined by the appended claims.

20: interrogator 100: interrogation signal providing unit
110: DAC 200: band conversion unit
210: up conversion unit 300: power amplifier
10: receiver 1000: precision clock forming unit
2000: receiving unit 3000: signal processing unit
4000: message processing unit
S100~S500: Overview of each step of the method of determining the position of the aircraft

Claims (10)

As a method for locating an aircraft, the method comprises:
Transmitting, by an interrogator, a first interrogation signal to the aircraft;
detecting, by a receiver, a response to the first interrogation signal transmitted by the vehicle transponder, and transmitting the received time to a central processing unit;
Transmitting, by the interrogator, a second interrogation signal to the aircraft;
detecting, by the receiver, a response to the second interrogation signal transmitted by a transponder included in the vehicle, and transmitting the received time to the central processing unit; and
a time from when the interrogator transmits the first interrogation signal to a time when the transponder receives the first interrogation signal;
The sum of the times from the time when the transponder transmits the response signal to the first interrogation signal to the time when the receiver receives the response signal to the first interrogation signal; and
a time from when the interrogator transmits the second interrogation signal to a time when the transponder receives the second interrogation signal; and
Determining the position of the vehicle by using the sum of the times from the time the transponder transmits the response signal to the second interrogation signal to the time the receiver receives the response signal to the second interrogation signal Flight body positioning method comprising a. According to claim 1,
The method,
Controlling, by the central processing unit, the interrogator to transmit the first interrogation signal prior to transmitting the first interrogation signal;
Prior to the step of transmitting the second interrogation signal, the central processing unit further comprises controlling the interrogator to transmit the second interrogation signal. According to claim 2,
The interrogator,
After transmitting the first interrogation signal and the second interrogation signal, the time at which each interrogation signal is transmitted is transmitted to the central processing unit. delete delete According to claim 1,
Wherein the first question is a Mode A or C signal. According to claim 6,
The response signal to the first query is transmitted 3 μsec after the transponder receives the Mode A or C signal. According to claim 1,
The second question is a method for locating an aircraft that is a Mode S signal. According to claim 8,
The response signal to the second question is transmitted 128 μsec after the transponder receives the Mode S signal. According to claim 1,
The method,
A method for locating an air vehicle performed by a plurality of interrogators and a plurality of receivers.

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