up [pdf]
from rsfproj import *

for file in ('beistack','beivrms'):
    Fetch(file+'.HH','midpts')
    Flow(file,file+'.HH','dd form=native')

Flow('wgkirch','beistack beivrms',
     'kirchnew velocity=${SOURCES[1]} | agc')
Result('wgkirch','wgkirch','grey title="Kirchhoff migration" ')

End()

sfdd
sfkirchnew
sfagc
sfgrey