SUSTKVEL - convert constant dip layer interval velocity model to the stacking velocity model required by sunmo sustkvel v= h= dip=0.0 outpar=/dev/tty Required parameters: v= interval velocities h= layer thicknesses at the cmp Optional parameters: dip=0.0 (constant) dip of the layers (degrees) outpar=/dev/tty output parameter file in the form required by sunmo: tv=zero incidence time pick vector v=stacking velocities vector Examples: sustkvel v=5000,6000,8000,10000 h=1000,1200,1300,1500 outpar=stkpar sunmo data.nmo sustkvel par=intpar outpar=stkpar sunmo data.nmo If the file, intpar, contains: v=5000,6000,8000,10000 h=1000,1200,1300,1500 then the two examples are equivalent. The created parameter file, stkpar, is in the form of the velocity model required by sunmo. Note: sustkvel does not have standard su syntax since it does not operate on seismic data. Hence stdin and stdout are not used. Caveat: Does not accept a series of interval velocity models to produce a variable velocity file for sunmo. Credits: CWP: Jack Technical Reference: The Common Depth Point Stack William A. Schneider Proc. IEEE, v. 72, n. 10, p. 1238-1254 1984 Formulas: Note: All sums on i are from 1 to k From Schneider: Let h[i] be the ith layer thickness measured at the cmp and v[i] the ith interval velocity. Set: t[i] = h[i]/v[i] t0[k] = 2 Sum t[i] * cos(dip) vs[k] = (1.0/cos(dip)) sqrt(Sum v[i]*v[i]*t[i] / Sum t[i]) Define: t0by2[k] = Sum h[i]/v[i] vh[k] = Sum v[i]*h[i] Then: t0[k] = 2 * t0by2[k] * cos(dip) vs[k] = sqrt(vh[k] / t0by2[k]) / cos(dip)