# SIOSEIS scripts to remove the ship heave. # # Heave removal using auto water bottom picks via # amplitude peak or user defined threshold # # This method of heave removal uses the differences between # auto identified sea floor picks and a smoothed seafloor to # shift traces. # # The automatic picker in process WBT picks the TWTT of the # first arrival and puts it in SEG-Y header word 50. Process # HEADER then copies header word 50 to word 59. # Process SWELL then computes the average twtt of the seafloor # within a window containing a user defined number of traces. # This average is then used shift the central trace within the # window, and shifts are written to header word 60. HEADER2 # overwrites header word 50 with the resulting seafloor time by # adding the trace shifts in 60 to the original pick in 59. # Process MUTE is then used to mute the water column based on # the TWTT of the "heave filtered" seafloor. # # **Remove 'swell' and 'header2' from the procs list in # order to simply trace amplitudes within the water # column. See sioheave_pltwbt for additional mods # needed to correctly make diagnostic plots of wbt # picks** sioseis << eof procs diskin header wbt header2 swell header3 diskoa prout end diskin fno 0 lno 999999 ipath ../segy/$1.sgy end end header fno 1 lno 999999 l6 = l3 l7 = l4 end end wbt thres $2 track $3 end end header2 fno 1 lno 999999 r59 = r50 end end swell n $4 hdr 50 index 60 end end header3 fno 1 lno 999999 r50 r59 + r60 end end #mute # fno 1 ttp 1 0 addwb yes end #end #gains # type 1 alpha 1.5 end #end #agc # fno 1 lno 999999 # winlen 0.05 pctagc 50 end #end diskoa opath ../segy/$1_sf.sgy end end prout fno 1 lno 999999 indices l3 r50 r59 r60 end end end