The concept of scale is of central importance in all problems related
to the interpretation of earth data. Inversion of geophysical data doe
s not at present, however, allow the incorporation of scale-dependent
information directly. This article presents an application of the wave
let transform to traveltime inversion where we are specifically concer
ned with the selection and application of a priori scale information i
n the wavelet domain to reconstruct tomographic models. Because of the
nature of the problem, the wavelet basis chosen for this example is t
he Haar basis. The results are compared with the classic damped least-
squares (DLS) method, which is a special case of the wavelet transform
approach when all the scales are treated equally. We show that with s
cale-dependent prior information, most of the artifacts created by the
DLS technique are diminished considerably.