Method and apparatus for the determination of start time difference and overall phase shift between two signals
AssigneeDeutsche Texaco Aktiengesellschaft
InventorEike Rietsch
Life of this patent
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Abstract
Apparatus and method determines the time shift and total phase difference between two alternating current signals. A value .psi. (f) corresponding to the phase relationship between the two signals is determined for each frequency f contained in the two signals. A slope A and an ordinate section B of the best fitting straight line g(f)=Af + B through the totality of the values .psi. (f) so obtained is determined. The phase shift .psi..sub.o =B modulo (2.pi.) is determined from the ordinate section B and the time shift .tau. = A/2.pi. from the slope A.
Claims15
A method for determining a time shift and a total phase difference between two signals, comprising the steps of
- a. determining a value .psi.(f), representative of the phase relationship between the two signals, for each frequency f contained in the two signals;
- b. providing g signals, corresponding to the values, in accordance with the determination and corresponding f signals;
- c. determining a slope A and an ordinate intercept B of a best-fitting straight line g(f) = Af+B through the totality of the values .psi. in accordance with the g and f signals
- d. providing a slop signal and an intercept signal corresponding to the slope A and the ordinate intercept B in accordance with the next previous step;
- e. providing a signal .tau. corresponding to the time shift in accordance with the slope signal and the following equation
- .tau. = A/2.pi.;
- and
- f. providing a signal .psi..sub.0 corresponding to the total phase shift in accordance with the intercept signal and the following equation
- .psi..sub.0 = B modulo (2.tau.).
Apparatus for determining the time shift and total phase difference between two signals comprising phase difference means adapted to receive the two signals for determining a value .psi.(f), representative of the phase relationship between the two signals, for each frequency f contained in the two signals, and providing corresponding g signals, and their associated f signals, slope and intercept means connected to the phase difference means for determining a slope A and an ordinate intercept B of a best fitting straight line g(f) = Af+B through the totality of the values .psi. in accordance with the f and g signals and providing signals A and B corresponding to the slope A and the ordinate intercept B;
- time shift signal means connected to the slope and intercept means for providing an output corresponding to the time shift .tau. in accordance with signal A and the following equation:
- .tau. = A/2.pi.;
- and total phase shift signal means connected to the slope and intercept means for providing an output .psi..sub.0 corresponding to the total phase shift in accordance with signal B and the following equation:
- .psi..sub.0 = B modulo (2.pi.).
Dependencies are inferred from the claim text.