Method and apparatus for the determination of start time difference and overall phase shift between two signals

Claim 3

A method as described in claim 1 wherein the values ψ(f) giving the phase relationship between the two signals are equal to the arcustangent of the quotient of co-spectrum and quadrature spectrum of the two signals.

Claim 4

A method as described in claim 2, further comprising the step of determining a residual phase shift ψ(f)-g(f), and representing the residual phase shift analogically in the form of a curve dependent on the frequency.

Claim 5

A method as described in claim 3, wherein a characteristic value for the amount of residual phase shift within the frequency range of the two signals is determined and a corresponding digital output is provided.

Claim 6

A method as described in claim 4, wherein the absolute magnitude of the greatest residual phase shift is determined as the characteristic value for the amount of residual phase shift between the two signals.

Claim 7

A method as described in claim 5, further comprising the steps of determining the standard deviation of the residual phase shift as a characteristic value for the amount of residual phase shift, and providing a corresponding digital output.

Claim 8

A method as described in claim 1 wherein the values ψ(f) giving the phase relationship between the two signals are equal to the difference of the phase spectra of the two signals, so that a multiple of 2π is added to, or subtracted from, the difference of the two phase spectra until the thus modified difference varies from the difference established at the preceding frequency by less than π.

Claim 9

A method as described in claim 7 further comprising the steps of determining a residual phase shift ψ(f)-g(f) and is represented analogically in the form of a curve dependent on the frequency.

Claim 10

A method as described in claim 8, wherein a characteristic value for the amount of residual phase shift within the frequency range of the two signals is determined and a corresponding digital output is provided.

Claim 11

A method as described in claim 9, wherein the absolute magnitude of the greatest residual phase shift is determined as the characteristic value for the amount of residual phase shift between the two signals.

Claim 12

A method as described in claim 10, further comprising the steps of determining the standard deviation of the residual phase shift as a characteristic value for the amount of residual phase shift, and providing a corresponding digital output.

Claim 13

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 ψ(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 ψ 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 τ in accordance with signal A and the following equation: τ = A/2π; and total phase shift signal means connected to the slope and intercept means for providing an output ψ 0 corresponding to the total phase shift in accordance with signal B and the following equation: ψ.sub.0 = B modulo (2π).

Claim 14

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 ψ(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 ψ 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 τ in accordance with signal A and the following equation: τ = A/2π; and total phase shift signal means connected to the slope and intercept means for providing an output ψ 0 corresponding to the total phase shift in accordance with signal B and the following equation: ψ.sub.0 = B modulo (2π).

Claim 15

Apparatus as described in claim 12 further comprising means connected to the slope and intercept means for providing an output corresponding to a residual phase shift, which is the difference between points on the best fitted straight line and their corresponding ψ values, in accordance with the g signals.

Claim 16

Apparatus as described in claim 13 in which the residual phase shift output corresponds to the absolute value of the residual phase shift.

Claim 17

Apparatus as described in claim 13 in which the residual phase shift output corresponds to the standard deviation of the residual phase shift.