Channel impulse response arrival uncertainty using source of opportunity for tomography

Passive acoustic tomography exploits the acoustic energy generated by sources with unknown spectral content such as sources of opportunity (e.g., cargo ships) to study the ocean. The recording at each sensor within a vertical line array (VLA) is the channel impulse response (CIR) convolved with the noise generated by the moving random radiator. Using an incremental approach, we estimate the source signal locally at three VLAs by beamforming on the direct ray-path to deconvolve each CIR. CIR arrival uncertainty is inversely proportional to the bandwidth of the source and SNR, the latter estimated from the deconvolved time domain waveform. Over the 10 min source track, we present the time evolution of CIR arrival uncertainty computed at three VLAs horizontally separated by 1.5 km and discuss constraints on integration time. Data are presented using the Noise Correlation 2009 Experiment and application to the Santa Barbara Channel Experiment 2016 is discussed.