Correlation function measuring method and apparatus
First Claim
1. A correlation function measuring method in which a first monitored signal is processed by a first signal processing means to give a first spectrum, a second monitored signal is processed by a second signal processing means to give a second spectrum, and a correlation function between the first spectrum and the second spectrum is measured, the method comprising the steps of:
- inputting, before measuring the correlation function, correction signals to the first signal processing means and the second signal processing means, and obtaining correction values corresponding to frequencies of the correction signals, based on spectrums from the first and second signal processing means; and
in measuring the correlation function, producing a correlation function between the first spectrum and the second spectrum by using the correction values corresponding to the frequencies;
wherein when obtaining the correction values, first correction signals are supplied to the first and second signal processing means and their frequencies swept to produce magnitude correction data corresponding to the frequencies based on spectrums from the first and second signal processing means, and second correction signals are supplied to the first and second signal processing means to produce phase correction data corresponding to the respective frequencies based on spectrums from the first and second signal processing means, and the correction values corresponding to the respective frequencies are obtained based on the magnitude correction data and the phase correction data;
wherein the first correction signals are continuous waves while the second correction signals are modulated waves.
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Abstract
A correlation function measuring method and apparatus can correct a correlation vector with high accuracy. The correlation function measuring apparatus includes first signal processing means 18a to 22a for processing a first monitored signal to give a first spectrum, second signal processing means 18b to 22b for processing a second monitored signal to give a second spectrum, correction value computing means 26 for inputting correction signals to the first and second signal processing means to give correction values corresponding to respective frequencies, based on the first spectrum and the second spectrum, and correlation function computing means 30 for obtaining a correlation function between the first spectrum and the second spectrum by using correction values given by the correction value computing means.
16 Citations
10 Claims
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1. A correlation function measuring method in which a first monitored signal is processed by a first signal processing means to give a first spectrum, a second monitored signal is processed by a second signal processing means to give a second spectrum, and a correlation function between the first spectrum and the second spectrum is measured, the method comprising the steps of:
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inputting, before measuring the correlation function, correction signals to the first signal processing means and the second signal processing means, and obtaining correction values corresponding to frequencies of the correction signals, based on spectrums from the first and second signal processing means; and
in measuring the correlation function, producing a correlation function between the first spectrum and the second spectrum by using the correction values corresponding to the frequencies;
wherein when obtaining the correction values, first correction signals are supplied to the first and second signal processing means and their frequencies swept to produce magnitude correction data corresponding to the frequencies based on spectrums from the first and second signal processing means, and second correction signals are supplied to the first and second signal processing means to produce phase correction data corresponding to the respective frequencies based on spectrums from the first and second signal processing means, and the correction values corresponding to the respective frequencies are obtained based on the magnitude correction data and the phase correction data;
wherein the first correction signals are continuous waves while the second correction signals are modulated waves. - View Dependent Claims (2, 3, 4)
in giving the magnitude correction data, the frequencies of the first correction signals are scanned at a prescribed step and interpolated to give the magnitude correction data. -
3. A correlation function measuring method according to claim 1, wherein
the phase correction data are renewed more frequently than the magnitude correction data. -
4. A correlation function measuring method according to claim 3, wherein
when the renewed phase correction data are changed by an amount above a prescribed value with respect to the phase correction data at the time of obtaining the magnitude correction data, the magnitude correction data are renewed.
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5. A correlation function measuring apparatus, comprising:
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first signal processing means for processing a first monitored signal to give a first spectrum;
second signal processing means for processing a second monitored signal to give a second spectrum;
correction value computing means for inputting correction signals to the first signal processing means and the second signal processing means to obtain correction values corresponding to frequencies based on the spectrums from the first and second signal processing means; and
correlation function computing means for producing a correlation function between the first spectrum and the second spectrum by using the correction values established by the correction value computing means;
wherein when obtaining the correction values, first correction signals are supplied to the first and second signal processing means and their frequencies swept to produce magnitude correction data corresponding to the frequencies based on spectrums from the first and second signal processing means, and second correction signals are supplied to the first and second signal processing means to produce phase correction data corresponding to the respective frequencies based on spectrums from the first and second signal processing means, and the correction values corresponding to the respective frequencies are obtained based on the magnitude correction data and the phase correction data; and
wherein the first correction signals are continuous waves while the second correction signals are modulated waves. - View Dependent Claims (6, 7, 8)
the correction value computing means scans the frequencies of the first correction signal at a prescribed step and interpolates to give the magnitude correction data. -
7. A correlation function measuring apparatus according to claim 5, wherein
the correction value computing means renews the phase correction data more frequently than the magnitude correction data. -
8. A correlation function measuring apparatus according to claim 7, wherein
the correction value computing means renews the magnitude correction data when the renewed phase correction data has changed by an amount above a prescribed value with respect to the phase correction data given at the time for obtaining the magnitude correction data.
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9. A correlation function measuring method in which a first monitored signal is processed by a first signal processing means to give a first spectrum, a second monitored signal is processed by a second signal processing means to give a second spectrum, and a correlation function between the first spectrum and the second spectrum is measured, the method comprising the steps of:
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inputting, before measuring the correlation function, correction signals to the first signal processing means and the second signal processing means, and obtaining correction values corresponding to frequencies of the correction signals, based on spectrums from the first and second signal processing means;
in measuring the correlation function, producing a correlation function between the first spectrum and the second spectrum by using the correction values corresponding to the frequencies;
creating a recurrence formula based on the correction values; and
renewing the correction values where correction values necessary to determine at least the recurrence formula are again obtained to renew the recurrence formula, and the correction values are renewed based on the renewed recurrence formula;
wherein when obtaining the correction values, first correction signals are supplied to the first and second signal processing means and their frequencies swept to produce magnitude correction data corresponding to the frequencies based on spectrums from the first and second signal processing means, and second correction signals are supplied to the first and second signal processing means to produce phase correction data corresponding to the respective frequencies based on spectrums from the first and second signal processing means, and the correction values corresponding to the respective frequencies are obtained based on the magnitude correction data and the phase correction data; and
wherein the first correction signals are continuous waves while the second correction signals are modulated waves.
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10. A correlation function measuring apparatus, comprising:
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first signal processing means for processing a first monitored signal to give a first spectrum;
second signal processing means for processing a second monitored signal to give a second spectrum;
correction value computing means for inputting correction signals to the first signal processing means and the second signal processing means to obtain correction values corresponding to frequencies based on the spectrums from the first and second signal processing means; and
correlation function computing means for producing a correlation function between the first spectrum and the second spectrum by using the correction values established by the correction value computing means;
wherein the correction value computing means produces a recurrence formula based on the correction values, where correction values necessary to determine at least the recurrence formula are again produced to renew the recurrence formula, thereby renewing the correction values based on the renewed recurrence formula;
wherein when obtaining the correction values, first correction signals are supplied to the first and second signal processing means and their frequencies swept to produce magnitude correction data corresponding to the frequencies based on spectrums from the first and second signal processing means, and second correction signals are supplied to the first and second signal processing means to produce phase correction data corresponding to the respective frequencies based on spectrums from the first and second signal processing means, and the correction values corresponding to the respective frequencies are obtained based on the magnitude correction data and the phase correction data; and
wherein the first correction signals are continuous waves while the second correction signals are modulated waves.
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Specification