Patent ID: 7652618

Claim:
A method for determining the velocity of a transmitter or an object, the method comprising: transmitting a signal from a transmitter toward an object; receiving a reflected signal of the transmitted signal from the object; organizing the reflected signal into data blocks containing samples; applying transform processing to a first group of the samples at a primary sampling rate, the first group of samples being within a data window associated with at least one of the data blocks; detecting an estimated frequency shift between the transmitted signal and the reflected signal based on a primary peak frequency determined by the transform processing at the primary sampling rate; applying transform processing to a second group of samples at a secondary sampling rate where the data window contains previously read samples and at least one new sample if the estimated frequency shift falls within a target response frequency band, the second group of samples being within the data window and comprising a lesser number of samples than the first group; detecting an observed frequency shift between the transmitted signal and the reflected signal based on a secondary peak frequency determined by the transform processing at the secondary sampling rate; and estimating a velocity of at least one of the object and the transmitter based on the estimated frequency shift, the observed frequency shift, or both.