  Three different transformation techniques, namely, (i)w-c, (ii) w-k and (iii)
tau-p, has been employed for generating multimodal dispersion images on the
basis of multi-channel analysis of surface waves (MASW) data recorded in
distance-time domain; here w= circular frequency, c = phase velocity, tau =
time intercept, p = phase slowness (1/c) and k = wavenumber. All the three
methods have been first clearly described. The results from these three
different transforms have been examined by using synthetic as well as field
data obtained from field tests using 48 geophones. The effect of sensor spread
length (X) and geophone numbers (M) on multimodal dispersion images were
examined. The solutions from these three transforms were found to match
generally well with each other. The w-c transform has been noted to provide the
most clarity since it does not require either high sampling rate as normally
needed for the tau-p method or inclusion of the zero padding of the data in a
distance domain for the w-k approach. The paper will be useful since it not
only describes the methods, but it brings out simultaneously their merits in
implementation and for generating the dispersion images.
