Patent ID: 8638641
Filing Date: 2014-01-28
Classification: G01S

Abstract:
1. A method for the passive tracking of a plurality of objects emitting respective signals in the form of a series of predetermined sounds, comprising the following steps: during successive processing time windows, acquiring raw analogue signals from a plurality of sensors, wherein at least some of the raw analogue signals correspond to the signals emitted by the plurality of objects; converting the raw analogue signals into digital data by sampling at a certain sampling frequency; filtering the digital data to eliminate spurious noise; eliminating echoes in the filtered signal by performing the following steps: obtaining, for each pair of sensors and each processing window, potential values (TDOA) of differences in arrival time of the stored signals to reach two distinct sensors; for each pair of sensors, verifying the coherence of the TDOAs, and selecting a number (nbTDOA) of filtered TDOAs coherent with each other; and from the filtered and coherent TDOAs, determining the successive instantaneous positions of the sources of the predetermined sounds by non-linear regression and deducing the path of the plural objects in their environment in real time.