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Analysis of seismic refraction amplitudes has the potential to produce a richer geological interpretation than if only travel-times are considered. In theory, the amplitude of a seismic head-wave is dependent on the strength of the shot and the offset at which it is measured. A constant of proportionality, called the head-wave coefficient, is a function of the elastic properties either side of the refracting interface. As the velocity contrast between the two media decreases, the head-wave coefficient increases.A detailed examination of refraction amplitude theory reveals that the head-wave coefficient is a product of two Zoeppritz transmission coefficients, a downgoing one at the source end and an upgoing one at the receiver end. The bulk amplitude of the head-wave coefficient is mainly due to the transmission coefficient at the receiver end. However, the receiver component is relatively insensitive to lateral changes. On the other hand, the transmission coefficient at the source end is sensitive to lateral changes.Theoretical models, which simulate laterally inhomogeneous geologies, are used to forwardmodel refraction amplitudes. The head-wave coefficient is then estimated via non-linear inversion of refraction amplitudes. Inverted shot and receiver terms are shown to be related to the transmission coefficients at the shot and receiver ends. The product of the inverted shot and receiver terms are related to the full head-wave coefficient. The inversion cannot separate the effect of velocity contrast from short-wavelength shot/geophone coupling effects. Smoothing of the inverted solution is suggested as a means of reducing coupling effects.For laterally inhomogeneous models, offset limiting is required prior to inversion in order to achieve successful separation of constituent amplitude components. For offset-limited model data, the estimated model parameters exhibit consistency with the true model parameters in a relative sense.iii Non-uniqueness between parameter groups prohibits successful estimation of model parameters in an absolute sense. Calibration is therefore required to adjust the relative results obtained from inversion to results which are consistent with geology. This calibration uses independent estimates of weathering-layer velocity at several points along the seismic line.Calibration can be performed on the inverted shot terms alone, or the product of the inverted shot and receiver terms.The inversion methodology is evaluated on three real data sets. For the first Vibroseis dataset, the relative head-wave coefficient profile is consistent with that derived using an alternative approach (the Refraction Convolution Section). However, the implied weathering-layer velocity profile differs from that estimated by analysis of direct arrivals.For the second Vibroseis dataset, the derived weathering-layer velocity is reasonably consistent with the long-wavelength velocity profile derived from analysis of hammer shot records, acquired as part of the original survey. The CMP stack, incorporating t...

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P-wave reflection-statics solutions typically incorporate P-wave refraction data, derived from the first breaks of the production data. Similarly, converted-wave refractions, taken from inline-component recordings, can be exploited to yield S-wave receiver statics, required in the processing of converted-wave reflection data. This methodology requires extensions to well known P-wave refraction analysis methods. This paper outlines extensions of the slope-intercept method and the reciprocal method, required to analyse converted-wave refractions. We discuss the computation of S-wave time-depths and describe how the observed ratio of S-wave to P-wave time-depths can provide a useful estimate of the near-surface V P /V S ratio, which is of interest in the analysis of engineering rock strengths.We also include discussion of several related practical issues, with particular reference to dynamite sources. When the source is buried in the refractor, the required reciprocal times cannot be directly measured from the raw travel-time data. They can, however, be easily derived via correction using measured intercept times. Often converted-wave refractions are of poorer quality than conventional P-wave refractions, such that reversed refractions may not be available over some parts of the spread. In this situation, the preferred time-depth quantity cannot be computed. However, delay-times derived from singleended data can be substituted, particularly if lateral variations in refractor velocity are allowed for.The concepts outlined here are used in a companion paper to correct S-wave receiver statics in a coal-scale dataset from the Bowen Basin in central Queensland.