Certain aspects of prestack deconvolution

In a previous paper, we had shown that because of varying angles of incidence there is a varying degree of convolution down a trace and across a gather, necessitating deconvolution operators varying with time and offset. This idea is examined further in $t$-$x$ as well as $\tau$-$p$ domain. We suggest better ways to deconvolve data in $\tau$-$p$ domain, taking into account varying degree of convolution in this domain. We derive formulae for periods of surface multiples in $\tau$-$p$ domain, e.g., water column peg-legs and reverberations, which have a fixed period depending only on the value of $p$ -- and suggest a way to check/revise the picked velocity using the formulae, provided the multiples are well separated from the primary. Periodicity of two way surface multiples is also studied.