Patent ID: 7171007

Claim:
A signal processing apparatus comprising: a receiver operable to receive a respective signal from three or more spaced sensors, each representing a signal generated from a source; a first determiner operable to process the received sensor signals to determine the relative times of arrival of the signal from said source at said three or more spaced sensors; a second determiner operable to process the determined relative times of arrival using a best fit analysis to determine a parameter of a function which models the shape of a wavefront of the signal generated by said source at said sensors and which relates said determined relative times of arrival to the relative positions of said sensors; a third determiner operable to determine the direction in which said source is located relative to said sensors in dependence upon the determined function parameter; a divider operable to divide each received signal into a plurality of time sequential segments; an analyzer operable to analyze each segment of each received signal to determine a plurality of values representative of the frequency content of the signal in the segment at different frequencies, wherein said first determiner is operable to determine said relative times of arrival by comparing a current frequency value in a current time segment from a first one of said at least three sensors with a corresponding frequency value in a corresponding time segment from a second one of said at least three sensors, and wherein said second determiner is operable to determine a measure of the quality of the fit between the predetermined function having the determined function parameter and the relative times of arrival and the relative positions of said sensors; and an analyzer operable to analyze the determined function parameters for the different frequency values for which the quality measure is above a predetermined quality threshold, to identify a number of different groups of function parameters, each corresponding to a signal from a different source.