KR101078194B1 - Apparatus for clock correction and synchronization using Loran-C signals and method for clock correction and synchronization using the smae - Google Patents

Apparatus for clock correction and synchronization using Loran-C signals and method for clock correction and synchronization using the smae Download PDF

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KR101078194B1
KR101078194B1 KR1020100003957A KR20100003957A KR101078194B1 KR 101078194 B1 KR101078194 B1 KR 101078194B1 KR 1020100003957 A KR1020100003957 A KR 1020100003957A KR 20100003957 A KR20100003957 A KR 20100003957A KR 101078194 B1 KR101078194 B1 KR 101078194B1
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loran
signal
frequency
phase
value
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KR20110083960A (en
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이영규
이창복
양성훈
이상정
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한국표준과학연구원
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Abstract

The present invention provides a visual correction and synchronization device using a Loran signal, and a visual correction using the Loran signal, which can effectively compensate for the unilateral effect by estimating the unilateral effect present in the Loran signal by the amplitude and phase present in the Loran signal. It is about a synchronous method. Such a time correction and synchronization device using a Loran signal according to the present invention comprises: a Loran receiver which receives a Loran signal from a Loran radio station and outputs super pulses; A frequency controller for receiving the frequency generated by the clock generator and outputting a second pulse of a set period; A phase comparator for comparing phases of the reference pulses output from the Loran receiver with the phases of the pulses output from the frequency controller to measure a phase difference between the two pulses; A moving average calculation unit for measuring a moving average value of the Loran signal in the data about the time interval between the superpulses of the frequency oscillator and the superpulses of the Loran receiver measured by the phase comparator; A pattern generation and comparison unit configured to generate a compensation signal for correcting the unilateral effect of the Loran signal by comparing the moving average value obtained by the moving average calculation unit and the amplitude and phase of the pattern for estimating the unilateral effect present in the Loran signal; A frequency offset calculator for calculating a frequency offset value from the compensation signal generated by the pattern generation and comparison unit; And a control signal output unit for transmitting the frequency offset value calculated by the frequency offset calculator to the frequency controller. It provides a visual correction and synchronization device using a Loran signal, characterized in that configured to include.

Description

Apparatus for clock correction and synchronization using Loran-C signals and method for clock correction and synchronization using the smae}

The present invention relates to clock correction and synchronization for providing precise time, and more particularly, in the construction of a high-precision time synchronization system using a Loran signal, the unilateral effect of the Loran signal and the amplitude of the Loran signal The present invention relates to a time correction and synchronization device using a Loran signal capable of effectively compensating a unilateral effect by estimating and synchronizing with a phase, and a time correction and synchronization method using the same.

A mobile communication reference station or a power system requires high-precision time synchronization. In a system requiring high-precision time synchronization, a time synchronization is performed using a Loran-C (Loran-C) signal.

Here, Loran-C is a medium- and long-range navigation aid system, which is a terrestrial signal designed mainly for coastal navigation using carrier frequencies in the 100KHz band, and thus provides high frequency precision and time synchronization performance, thereby providing high frequency and time accuracy. Industries that need motivation are using it.

Since the effective distance of the Loran-C method is about twice as long as the Loran-A method, and the positioning accuracy is also about 2 times or more, Loran-C is mainly used than Loran-A. These Loran-C radio stations are helping to navigate aircraft and ships sailing around the territorial waters. Currently, Loran-C signals are transmitted from two Loran-C transmitters in Pohang and Gwangju.

One of the factors that greatly influence the performance when visual synchronization using the Loran-C signal is the unilateral effect of the terrestrial signal. This is a one-day cycle that typically spans hundreds of ns. Therefore, a more precise method of visual synchronization below this fluctuation is required to compensate for this.

Hereinafter, a time correction and synchronization device using a Loran signal according to the prior art will be described with reference to the accompanying drawings.

1 is a block diagram illustrating a time correction and synchronization device using a Loran signal according to the prior art. As shown in FIG. 1, a time correction and synchronization device using a Loran signal according to the prior art includes a Loran-C receiver 1, a frequency oscillator 2, a frequency controller 3, a phase comparator 4, and a frequency offset calculator. (5) and a control signal output unit (6).

Here, the Loran-C receiver 1 receives the Loran-C signal from a Loran radio station (not shown) and outputs super pulses.

The clock generator 2 generates a reference frequency.

The frequency controller 3 receives the reference frequency generated by the clock generator 2 and outputs a super pulse.

The phase comparator 4 receives the respective superpulses output from the Loran-C receiver 1 and the frequency controller 3, compares the phases of the two pulses, and generates a time interval, that is, a phase difference value of the two pulses. (Measure).

The frequency offset calculator 5 collects a predetermined number of measured phase difference value data, calculates an average value, and calculates a slope and a deviation using a line fitting algorithm. Then, using the value obtained by the line fitting, obtain the value of the time variation amount and use the frequency offset value.

Figure 112010002843675-pat00001
Can be obtained as in Equation 1 below.

Figure 112010002843675-pat00002

Where T is the measurement time,

Figure 112010002843675-pat00003
Is the amount of time change during the measurement time,
Figure 112010002843675-pat00004
Is the input reference frequency. On the other hand, the measurement time T is the total time used to generate data to be used for line fitting.

The control signal output 6 transmits the frequency offset value to the frequency controller 3.

Then, the frequency controller 3 changes the value of the output frequency by adding the value corresponding to the frequency offset value transmitted from the control signal output unit 6, and the super pulse generated based on this is used for time synchronization.

However, in the conventional technology, since the unilateral effect exists in the Loran-C signal and the fluctuation is reflected in the frequency offset measurement, there is a problem in that the synchronous performance corresponding to the unilateral effect is degraded.

Accordingly, the present invention is to solve all the disadvantages and problems of the prior art as described above, the present invention is the unilateral effect by estimating the unilateral effect present in the Loran signal to the amplitude and phase present in the Loran signal, corrected and synchronized It is an object of the present invention to provide a visual correction and synchronization device using Loran signal and a visual correction and synchronization method using the same.

The present invention for achieving the above object, the Loran receiving unit for receiving the Loran signal from the Loran radio station and outputting a super pulse; A frequency controller for receiving the frequency generated by the clock generator and outputting a second pulse of a set period; A phase comparator for comparing phases of the reference pulses output from the Loran receiver with the phases of the pulses output from the frequency controller to measure a phase difference between the two pulses; A moving average calculation unit for measuring a moving average value of the Loran signal in the data about the time interval between the superpulses of the frequency oscillator and the superpulses of the Loran receiver measured by the phase comparator; A pattern generation and comparison unit configured to generate a compensation signal for correcting the unilateral effect of the Loran signal by comparing the moving average value obtained by the moving average calculation unit and the amplitude and phase of the pattern for estimating the unilateral effect present in the Loran signal; A frequency offset calculator for calculating a frequency offset value from the compensation signal generated by the pattern generation and comparison unit; And a control signal output unit for transmitting the frequency offset value calculated by the frequency offset calculator to the frequency controller. It provides a visual correction and synchronization device using a Loran signal, characterized in that configured to include.

The moving average value measured by the moving average calculation unit is mvi, i is i periods, and xj is the time between the superpulse of the Loran-C receiver measured by the phase comparator and the ultrapulse of the frequency controller during period i. In the case of the sum data of the phase difference by the interval,

Figure 112010002843675-pat00005
, here,
Figure 112010002843675-pat00006
Is preferably.

On the other hand, in order to generate the compensation signal required for correction, the pattern generation and comparison unit sets the frequency domain according to the data characteristics to selectively select the frequency required for compensation, and frequency components within the region set by the least square frequency estimation method. Selects only frequencies having a power value corresponding to a predetermined threshold or more using a power ratio to maximum power among estimated frequency components, and uses a period for a frequency component having maximum power among estimated frequencies. After smoothing the data, it is desirable to estimate the amplitude and phase based on it.

And amplitude is the amplitude

Figure 112011048000480-pat00007
The power magnitude obtained by the least square frequency estimation
Figure 112011048000480-pat00008
Is called,
Figure 112011048000480-pat00009
Is the magnitude of power over the entire frequency,
Figure 112011048000480-pat00010
Is the maximum value of the smoothed signal,
Figure 112011048000480-pat00011
Preferred by

On the other hand, the phase

Figure 112010002843675-pat00012
,
Figure 112010002843675-pat00013
Are the maximum phase values obtained from the measured data, respectively.
Figure 112010002843675-pat00014
Is the minimum phase value obtained from the measured data, respectively,
Figure 112010002843675-pat00015
Preferred by

In addition, the maximum phase value (

Figure 112010002843675-pat00016
Is the smoothing period T, and the maximum value of the smoothed signal for the smoothing period
Figure 112010002843675-pat00017
The index value of is called Imax and the minimum value of the smoothed signal for the smoothing period.
Figure 112010002843675-pat00018
If the index value of is called Imin
Figure 112010002843675-pat00019
Preferably calculated by

Meanwhile, estimates of amplitude and phase are used to generate cosine signals for individual frequency components.

Figure 112010002843675-pat00020
If
Figure 112010002843675-pat00021
To obtain the compensation signal according to the sum of the individual frequency components.
Figure 112010002843675-pat00022
If
Figure 112010002843675-pat00023
Preferably produced by

Meanwhile, the Loran receiver is preferably at least one of a Loran-C receiver or a Loran-A receiver.

In order to achieve the above object, the present invention includes a step of outputting a reference pulse pulse according to the Loran signal received by the Loran signal receiving the Loran signal from the Loran radio station, the frequency control unit outputs the set pulse; Measuring a phase difference by comparing a phase according to a time interval between two reference pulses with respect to the reference pulses output from the Loran receiver and the pulses output from the frequency controller; Measuring a moving average value in a moving average calculation unit with respect to data on the phase difference measured by the phase comparing unit; And generating a compensation signal for correcting the unilateral effect of the Loran signal by comparing the moving average value obtained by the moving average calculator with the amplitude and the phase of the pattern in which the unilateral effect present in the Loran signal is estimated. It provides a time correction and synchronization method using a Loran signal, characterized in that comprises a.

Herein, the generating of the compensation signal correcting the unilateral effect of the Loran signal in the pattern generation and comparison unit may include setting a frequency domain suitable for data characteristics to selectively select a frequency required for compensation, and a minimum square frequency. Estimating a frequency component within an area set by the estimation method, selecting only a frequency having a power value corresponding to a predetermined threshold or more using a power ratio to maximum power among the estimated frequency components, and estimating frequency And smoothing the original data using the period for the frequency component having the maximum power, and estimating and generating the amplitude and phase based on the original data.

On the other hand, it is preferable that the unilateral effect pattern uses the pattern which estimated the unilateral effect in the Loran receiver which exists in the area | region which receives the Loran signal from a Loran radio station.

The method may further include transmitting the generated compensation signal to the frequency offset calculator for calculating the frequency offset after generating the compensation signal in the pattern generation and comparison unit, and obtaining the frequency offset value through line fitting in the frequency offset calculator. And transmitting the frequency offset value from the control signal output unit to the frequency control unit to correct the ultra-pulse generated by the frequency control unit.

In the time correction and synchronization device using the Loran signal according to the present invention, and the time correction and synchronization method using the same, the Loran-C signal is present in the Loran-C signal in the implementation of the synchronization device requiring high time synchronization. By effectively compensating the unilateral effect, it is possible to provide a stable synchronization device with higher performance. In particular, the present invention can be used more effectively in the construction of a time synchronization device requiring ultra high precision time synchronization of tens of nanoseconds or less.

1 is a block diagram illustrating a time synchronization and correction system using a Loran signal according to the prior art;
2 is a block diagram for explaining a time correction and synchronization device using a Loran signal according to the present invention;
3 is a flowchart illustrating a time correction and synchronization method using a time correction and synchronization device using a Loran signal according to the present invention.

Hereinafter, a preferred embodiment of a time correction and synchronization device using a Loran signal and a time correction and synchronization method using the same according to the present invention will be described in detail with reference to the accompanying drawings.

In addition, the terminology used in the present invention was selected as a general term that is widely used at present, but in certain cases, the term is arbitrarily selected by the applicant, and in this case, since the meaning is described in detail in the corresponding part of the present invention, a simple term It is to be understood that the present invention is to be understood as a meaning of terms rather than names.

Further, in describing the embodiments, descriptions of technical contents which are well known in the technical field to which the present invention belongs and which are not directly related to the present invention will be omitted. This is for the sake of clarity of the present invention without omitting the unnecessary explanation.

2 is a block diagram illustrating a time correction and synchronization device using a Loran signal according to the present invention. As shown in FIG. 2, the time correction and synchronization device using the Loran signal according to the present invention includes a Loran-C receiver 10, a clock generator 20, a frequency controller 30, and a phase comparator 40. The average calculation unit 50, the pattern generation and comparison unit 60, the frequency offset calculation unit 70 and the control signal output unit 80.

The Loran-C receiver 10 receives a Loran-C signal from a Loran radio station (not shown) and outputs a super pulse.

The clock generator 20 generates a reference frequency.

The frequency controller 30 receives the reference frequency generated by the clock generator 20 and outputs a super pulse.

The phase comparator 40 receives the respective superpulses output from the Loran-C receiver 10 and the frequency controller 30 and compares the phases of the two superpulses to generate a time interval, that is, a phase difference value of the two superpulses. (Measure).

The moving average calculation unit 50 averages a predetermined average of data on the time interval between the second pulses of the frequency controller 20 with respect to the second pulse of the Loran-C receiver 10 measured by the time interval coefficient unit 30. Collect as many periods as the moving average. At this time, the moving average value

Figure 112010002843675-pat00024
In this case, the moving average value (
Figure 112010002843675-pat00025
) Can be obtained as in Equation 2.

Figure 112010002843675-pat00026

Where i is i periods,

Figure 112010002843675-pat00027
Is the total data of the phase difference by the time interval between the super pulses of the Loran-C receiver 10 and the super pulses of the frequency oscillator 20 measured by the time interval coefficient unit 30 during the period i.

The pattern generation and comparison unit 60 compares the previous univariate effect pattern previously obtained using the sum data of the phase differences obtained by the moving average calculation unit 50 to generate the Loran-C generated by the Loran-C receiver 10. Compensate for the unilateral effects of the signal. Here, the previously obtained previous pattern uses a pattern that estimates the one-sided effect at the Loran receiver existing in the region receiving the Loran-C signal from the Loran radio station.

In this case, when the unilateral effect pattern is yn, it may be estimated as in Equation 3 below.

Figure 112010002843675-pat00028

here,

Figure 112010002843675-pat00029
Is the amplitude of the estimated sinusoidal pattern for the unilateral effect of the Loran-C signal,
Figure 112010002843675-pat00030
Is the phase value,
Figure 112010002843675-pat00031
Is the bias value.

In more detail, the estimated pattern for the unilateral effect of the Loran-C signal in the pattern generation and comparison unit 60 uses the estimated value of the unilateral effect in the region receiving the Loran-C signal. The procedure is as follows.

First, a frequency range must be set to match the data characteristics. In this case, as in Equation 3, a frequency domain for 24 hours may be set, or a frequency domain for 12 hours or 6 hours may be set. Here, first setting the region of the frequency component estimated according to the data characteristics and purposes is necessary to selectively select a frequency necessary for compensation among many frequency components. At this time, in order to compensate for the unilateral effect, it is preferable to set the frequency domain for 24 hours.

Then, the frequency components within the set area are estimated using the least square frequency estimation (LSSA) method.

Subsequently, only frequencies having a power value corresponding to a predetermined threshold or more are selected using the power ratio to the maximum power among the estimated frequency components. That is, even if a frequency range is determined, a significant number of frequencies detected within the range may occur. Therefore, since the performance improvement that can be expected by compensating for all frequency components is not so large, it is to set a frequency selection range having a power value corresponding to the set threshold or more.

Then, the original data is smoothed using a period for a frequency component having the maximum power among the estimated frequencies, and then amplitude and phase are estimated based on the original data.

Here, the period is obtained using a conventional f = 1 / T, and the amplitude is obtained by the cosine function of the sinusoidal form of the sine wave of the Loran-C signal estimated for each Loran-C frequency received by the Loran-C receiver 10. Amplitude

Figure 112010002843675-pat00032
It can be obtained by using the following equation (4).

Figure 112010002843675-pat00033

here,

Figure 112010002843675-pat00034
Is the power magnitude obtained by LSSA,
Figure 112010002843675-pat00035
Is the magnitude of power over the entire frequency (
Figure 112010002843675-pat00036
),
Figure 112010002843675-pat00037
Is the maximum value of the smoothed signal.

In addition, the estimation of the phase value of the cosine function for each frequency can be obtained as shown in Equation 5 below.

Figure 112010002843675-pat00038

here,

Figure 112010002843675-pat00039
Is the phase value of the estimated cosine function,
Figure 112010002843675-pat00040
Are the maximum phase values obtained from the measured data, respectively. Is the minimum phase value obtained from the measured data, respectively.
Figure 112010002843675-pat00042
) And the minimum phase value (
Figure 112010002843675-pat00043
) Can be calculated as shown in Equation 6 below.

Figure 112010002843675-pat00044

Where T is the smoothing period, and Imax and Imin are the maximum values of the smoothed signal for this period, respectively.

Figure 112010002843675-pat00045
And the minimum value
Figure 112010002843675-pat00046
Index value.

Using the estimated values for amplitude and phase, the cosine signal for each frequency component can be obtained as shown in Equation 7 below.

Figure 112010002843675-pat00047

In addition, by combining the individual frequency components obtained in Equation 7 as in Equation 8, a final compensation signal is generated and subtracted from the originally received Loran-C signal to compensate for the unilateral effect.

Figure 112010002843675-pat00048

That is, after generating individual compensation signals using the estimated amplitude and phase values, as shown in Equation 7, and adding these signals as shown in Equation 8 to generate the overall compensation signal, the original signal, that is, the Loran-C receiver 10 One side effect can be compensated by subtracting from the received signal.

Using the compensated signal, the frequency offset calculator 70 obtains a frequency offset value through line fitting.

The control signal output unit 80 obtained by the frequency offset calculator 70 transmits the frequency offset value to the frequency controller 30.

Then, the frequency control unit 30 corrects the value of the output frequency by adding a value corresponding to the frequency offset value transmitted from the control signal output unit 80, and the ultra-pulse generated based on this is used for time synchronization.

3 is a flowchart illustrating a clock correction and synchronization method using a clock correction and synchronization device for providing a precise time using a Loran signal according to the present invention. The clock correction and synchronization method using the clock correction and synchronization device for providing a precise time using the Loran signal according to the present invention, as shown in Figure 3, the Loran receiving a Loran-C signal from a Loran radio station (not shown) -C outputs the reference superpulse received by the receiver 10, the frequency control unit 30 outputs the superpulse (S10)

The phase comparator 40 receives the reference superpulse output from the Loran-C receiver 10 and the superpulse output from the frequency controller 30 and compares the phases according to the time intervals of the two superpulses. The difference value is measured (S20).

Next, the moving average calculation unit 50 preliminarily pre-sets data on the time interval between the second pulses of the frequency oscillator 20 with respect to the second pulse of the Loran-C receiver 10 measured by the time interval coefficient unit 30. Collect the average period determined in the measure the moving average value (S30).

On the other hand, the moving average value obtained in the moving average calculation unit 50 as described above is generated in the Loran-C receiving unit 10 in comparison with the previous one-way effect pattern previously obtained in the pattern generation and comparison unit 60. Compensate for the unilateral effects of the signal. Here, the previously obtained previous pattern uses a pattern that estimates the one-sided effect at the Loran receiver existing in the region receiving the Loran-C signal from the Loran radio station.

At this time, first, the pattern generation and comparison unit 60 sets a frequency domain suitable for the data characteristics (S40).

In addition, the pattern generation and comparison unit 60 estimates frequency components within a set region by using a least square spectral analysis (LSSA) method (S50).

Next, the pattern generation and comparison unit 60 selects only a frequency having a power value corresponding to a predetermined threshold or more using the power ratio to the maximum power among the estimated frequency components (S60).

Subsequently, the pattern generation and comparison unit 60 estimates an amplitude and a phase value with respect to the frequency having the maximum power (S70).

In operation S80, a compensation signal is generated using the estimated amplitude and phase values.

Then, the unilateral effect is compensated for using the generated compensation signal (S90).

At this time, the one-sided effect may be compensated for by subtracting from the original signal, that is, the signal received by the Loran-C receiver 10.

Using the compensated signal, the frequency offset calculator 70 obtains a frequency offset value through line fitting.

The control signal output unit 80 obtained by the frequency offset calculator 70 transmits the frequency offset value to the frequency controller 30.

Then, the frequency control unit 30 corrects the value of the output frequency by adding a value corresponding to the frequency offset value transmitted from the control signal output unit 80, and the ultra-pulse generated based on this is used for time synchronization.

On the other hand, the present invention has been described mainly for the Loran-C receiver, it can be applied to the Loran-A receiver.

Although the present invention has been described by way of example as described above, the present invention is not necessarily limited to these examples, and various modifications can be made without departing from the spirit of the present invention. Therefore, the examples disclosed in the present invention are not intended to limit the technical idea of the present invention but to explain the present invention, and the scope of the technical idea of the present invention is not limited by these examples. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

10: Loran-C receiver 20: Clock generator
30: frequency control unit 40: phase comparison unit
50: moving average calculation unit 60: pattern generation and comparison unit
70: frequency offset calculator 80: control signal output unit

Claims (12)

A Loran receiver for receiving a Loran signal from the Loran radio station and outputting super pulses;
A frequency controller for receiving the frequency generated by the clock generator and outputting a second pulse of a set period;
A phase comparator for comparing phases of the reference pulses output from the Loran receiver with the phases of the pulses output from the frequency controller to measure a phase difference between the two pulses;
A moving average calculator configured to measure a moving average value of the Loran signal from data about a time interval between the pulses of the frequency oscillator and the pulses of the Loran receiver measured by the phase comparator;
A pattern generation and comparison unit configured to generate a compensation signal for correcting the unilateral effect of the Loran signal by comparing a moving average value obtained by the moving average calculator with a amplitude and a phase of a pattern for estimating the unilateral effect present in the Loran signal;
A frequency offset calculator for calculating a frequency offset value from the compensation signal generated by the pattern generation and comparison unit; And
A control signal output unit which transmits the frequency offset value calculated by the frequency offset calculator to the frequency controller; Vision correction and synchronization device using a Loran signal, characterized in that configured to include.
The method of claim 1,
The moving average value measured by the moving average calculation unit is mvi, i is i periods, and xj is a super pulse of the Loran-C receiver measured by the phase comparator and a second pulse of the frequency controller during period i. If the sum data of the phase difference by the time interval between
remind
Figure 112011048000480-pat00049
, here,
Figure 112011048000480-pat00050
A time correction and synchronization device using a Loran signal, which is obtained by
The method of claim 1,
In order to generate a compensation signal required for the correction, the pattern generation and comparison unit,
In order to selectively select the frequency required for the compensation, a frequency domain is set according to data characteristics, a frequency square within the set region is estimated by a least square frequency estimation method, and the maximum power of the estimated frequency components The power ratio is used to select only frequencies having a power value corresponding to a predetermined threshold value or more, and the original data is smoothed using a period for a frequency component having the maximum power among the estimated frequencies, and based on the amplitude and phase, And a time correction and synchronization device using a Loran signal, characterized by estimating a. The method of claim 3, wherein
The amplitude is the amplitude
Figure 112011048000480-pat00051
The power magnitude obtained by the least square frequency estimation
Figure 112011048000480-pat00052
Is called,
Figure 112011048000480-pat00053
Is the magnitude of power over the entire frequency,
Figure 112011048000480-pat00054
Is the maximum value of the smoothed signal,
Figure 112011048000480-pat00055
A time correction and synchronization device using a Loran signal, characterized in that estimated by.
The method of claim 3, wherein
The phase is the phase
Figure 112010002843675-pat00056
,
Figure 112010002843675-pat00057
Are the maximum phase values obtained from the measured data, respectively.
Figure 112010002843675-pat00058
Is the minimum phase value obtained from the measured data, respectively.
Figure 112010002843675-pat00059
A time correction and synchronization device using a Loran signal, characterized in that estimated by.
The method of claim 5, wherein
The maximum phase value (
Figure 112010002843675-pat00060
Denotes the smoothing period T and a maximum value of the smoothed signal for the smoothing period.
Figure 112010002843675-pat00061
The index value of is denoted by Imax and the minimum value of the smoothed signal for the smoothing period.
Figure 112010002843675-pat00062
If the index value of is called Imin,
Figure 112010002843675-pat00063
A time correction and synchronization device using a Loran signal, characterized in that calculated by.
The method according to claim 3, 4 or 5,
The estimates for the amplitude and phase are used to generate cosine signals for the individual frequency components.
Figure 112010002843675-pat00064
In the case of
Figure 112010002843675-pat00065
Saved by
Compensation signal according to the sum of the individual frequency components
Figure 112010002843675-pat00066
Remind if
Figure 112010002843675-pat00067
A time correction and synchronization device using a Loran signal, characterized in that generated by.
The method of claim 1,
And the Loran receiver is at least one of a Loran-C receiver or a Loran-A receiver.
Outputting a reference superpulse according to the Loran signal received by the Loran receiver, which receives the Loran signal from the Loran radio station, and outputting the set superpulse by the frequency controller;
Measuring a phase difference by comparing, by a phase comparison unit, a phase according to a time interval between the two second pulses with respect to the reference pulses output from the Loran receiver and the pulses output from the frequency controller;
Measuring a moving average value in a moving average calculation unit with respect to the data on the phase difference measured by the phase comparing unit; And
Generating a compensation signal correcting the unilateral effect of the Loran signal by comparing the moving average value obtained by the moving average calculator with a amplitude and a phase of a pattern for estimating the unilateral effect present in the Loran signal. ; Vision correction and synchronization method using a Loran signal, characterized in that comprises a.
The method of claim 9,
Generating the compensation signal for correcting the unilateral effect of the Loran signal in the pattern generation and comparison unit,
Setting a frequency domain suitable for data characteristics to selectively select a frequency required for the compensation;
Estimating a frequency component within the set area using a least square frequency estimation method;
Selecting only a frequency having a power value corresponding to a predetermined threshold value or more using a power ratio to maximum power among the estimated frequency components;
And smoothing the original data using a period for a frequency component having the maximum power among the estimated frequencies, and estimating and generating the amplitude and phase based on the visual correction using the Loran signal. Motive method.
The method of claim 9,
The unilateral effect pattern is,
And a pattern obtained by estimating a unilateral effect at a Loran receiver in a region receiving the Loran signal from the Loran radio station.
The method of claim 9,
Transmitting the generated compensation signal to a frequency offset calculator for calculating a frequency offset after generating the compensation signal by the pattern generation and comparison unit;
Obtaining a frequency offset value through line fitting in the frequency offset calculator;
And transmitting the frequency offset value from the control signal output unit to the frequency control unit to correct the ultra-pulse generated by the frequency control unit.
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KR101654739B1 (en) * 2014-06-25 2016-09-06 연세대학교 산학협력단 Eloran asf survey system and method thereof
KR102080724B1 (en) * 2018-05-10 2020-02-24 연세대학교 산학협력단 Apparatus and method for calculating user position in multi-chain based long range navigation positing system
KR102054440B1 (en) 2018-11-30 2019-12-10 한국해양과학기술원 Apparatus and method for positioning loran-c/eloran multiple chain using toa measurement
CN112904386A (en) * 2021-01-15 2021-06-04 武汉梦芯科技有限公司 Method and system for compensating LoRa Doppler frequency offset based on GNSS

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US6308077B1 (en) 1992-10-02 2001-10-23 Motorola, Inc. Apparatus and method for providing synchronization of base-stations in a communication system

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