Abstract:

Slowness mapping is a method to estimate the angle of arrival of plane waves propagating across a sensor array. A review of time‐delay estimation and its application to slowness vector estimation, the forward model, the inverse model, azimuth estimation, and elevation estimation will be presented. A method for performance grading with “out‐of‐bounds” conditions is described, and in the special case of subsurface acoustic sensors, a method for discriminating against seismic signals. The method has been applied to locate the direction of Space Shuttle and other rocket launches, infrasonic emissions from clear air turbulence, and incidental sources found in the environment.