Patent ID: 8644113
Filing Date: 2014-02-04
Classification: G01S

Abstract:
1. A method comprising: receiving by a receiving device at a first location a sound signal from each of a set of sound signal sources, the sound signal emitting from each sound signal source being distinct from the sound signal emitting from another sound signal source and each sound signal source being uniquely identifiable within the set based on information provided in the sound signal; selecting sound signals received from a subset of the sound signal sources, the selected sound signals satisfying a reliability condition that filters out reflected sound signals, the location of each sound signal source providing a selected sound signal being known to the receiving device; determining the first location of the receiving device relative to the known locations of the subset of sound signal sources using a differential time of arrival measurement and cross-correlation; and determining a second location of the receiving device based on non-differential time of arrival measurements of sound signals received at the second location from fewer than the subset of sound signal sources received at the first location.