Patent ID: 8204707

Claim:
A method of estimating a time differential between a plurality of signals comprising: determining a filter response of a first electrical signal with a first filter array comprising a first plurality of bandpass filters including a first bandpass filter of a first frequency and a second bandpass filter of a second frequency different from the first frequency, wherein the determining is performed by splitting the first electrical signal into a first portion and a second portion, passing the first portion of the first electrical signal through the first bandpass filter to generate a first output and passing the second portion of the first electrical signal through the second bandpass filter to generate a second output, and combining the first and second outputs; determining a filter response of a second electrical signal with a second filter array comprising a second plurality of bandpass filters including a third bandpass filter of a third frequency and a fourth bandpass filter of a fourth frequency different from the third frequency, wherein the determining is performed by splitting the second electrical signal into a first portion and a second portion, passing the first portion of the second electrical signal through the third bandpass filter to generate a third output and passing the second portion of the second electrical signal through the fourth bandpass filter to generate a fourth output, and combining the third and fourth outputs; and determining, based at least on the filter response of the first electrical signal and the filter response of the second electrical signal, a time differential between the first electrical signal and the second electrical signal.