Patent ID: 8995226
Filing Date: 2015-03-31
Classification: G01S

Abstract:
1. A method for determining a distance travelled by a signal between a transmitter and a receiver in a medium, the method comprising: considering an unambiguous range, the unambiguous range greater than a distance to be travelled by a signal between the transmitter and the receiver; transmitting a signal from the transmitter to the receiver across the distance to be determined, the signal comprising at least three frequency components, the frequency components including: receiving the signal at the receiver; and determining, using a controller in communication with the receiver, a first estimate of the distance travelled by the signal between the transmitter and the receiver by using the variance of the received phase characteristics of the first frequency component with the received phase characteristics of the second frequency component; and determining, using the controller, the distance travelled by the signal between the transmitter and the receiver by using variance of the received phase characteristics of the first frequency component with the received phase characteristics of the third frequency component, as well as the first estimate of the distance travelled by the signal.