Method for obtaining confidence-limit values for seismic values calculated from Vibroseis data

A equation is derived to calculate the confidence limit values associated with seismic velocities calculated from time and distance data obtained using the Vibroseis method. This derived equation is a function of the uncertainty in the time measurement. Sources of timing uncertainty in the Vibroseis method are examined and estimates of the timing uncertainty are made. These estimates of the uncertainty in the time measurement are used to calculate the confidence limit values associated with calculated velocities. A monograph was constructed to provide quick approximation of these confidence limit values. The Vibroseis method is used in the nuclear weapons testing program to determine seismic velocities in various areas at the Nevada Test Site. These seismic velocities are used as parameters in ground motion and cavity growth model and as indicators of possible high acoustic impedance boundaries.