Co-Phase Analysis of Atmospheric Wave Data

Co-phase is a statistic designed for the detection and parameter estimation of signals by detector arrays. Ionospheric motions detected by an array of four phase-path sounders following a large earthquake are found by the co-phase technique to have a phase velocity equal to that of seismic Rayleigh waves of the same period, and to arrive from the direction of the epicentre. The calculation of co-phase for an 80-min sample of data from an 8-element array of microbarographs detects the presence of a signal from a high energy event despite a signal-to-noise ratio of less than unity. Co-phase analysis of acoustic signals generated by the Saturn-Apollo rocket launches indicates that these signals originate at ionospheric heights and propagate in a waveguide between a soundspeed maximum and a steep density gradient in the mesosphere.