Patent ID: 9151826
Filing Date: 2015-10-06
Classification: G01S

Abstract:
1. A receiver for locationing of a single frequency ultrasonic emitter, comprising: at least two microphones operable to receive an ultrasonic burst from a single frequency emitter and provide respective microphone signals; dual band pass filters centered at different frequencies from the single frequency ultrasonic burst and operable to derive two different frequency pulses form from the ultrasonic burst in each microphone signal; a low pass filter that provides a difference frequency of a multiplied combination of the two different ultrasonic frequency pulses from each microphone; and a correlator coupled to outputs of the dual band pass filters and the low pass filter, the correlator operable to correlate the two different frequency pulses in each microphone signal to determine a phase difference to establish a time difference of arrival of the ultrasonic burst at each microphone using the difference frequency.