Seismic velocity estimators

The layered subsurface geologic model leads to an approximate hyperbolic curve of delay vs sensor offset distance for seismic signals. Four "optimum" estimators for the rms seismic velocity are given and analyzed by simulation for rms error. Parameters varied include center-point depth (time), apriori velocity variance and mean, delay-estimate variance and inter-delay-estimate correlation. The maximum likelihood estimator is shown to be best when apriori information is relatively good, but a least mean square estimator is best otherwise.