Go to the list of seismic processes.
Go to SIOSEIS introduction.
Go to SIOSEIS examples.
Processes DESPIKE and WBT have the ability to filter the
data befor picking.
PASS - The passband of a 55 point time domain convolutional
zero phase bandpass filter to apply before picking.
The filtered data are NOT passed to the next seismic
process, thus the filter is applied "offline". The
low and high "corners" of the filter must be given.
Preset = none e.g. pass 100 200
The filter is the same as used in process FILTER parameters
ftype 99 fillen 55 pass "low" "high".
DESPIKE Example
This dataset was shot in the Arctic with an analog streamer that
got torn up by the ice. I suspect the spikes were caused by a wire
with a "flakey" connector in the streamer. The spike the got filtered
by the A/D. I was unable to find any despiking method that didn't kill
other traces too until filtering the data with high pass filter
(higher than the seismic frequencies of interest).
No filter
20x100 filter.
100x200 filter.
Despike parameters:
pass 100 200 fac 1 ses .5 .7 sel .5 1.5 kill yes end
WBT Example
Kentaro discovered that filtering Knudsen envelope data with a
low pass filter before using the "short-long ratio" method of picking
water bottom times was extremely effective.
Knudsen picks - avenor, mute, and gains based on Knudsen picks.
No processing
2x100 filter - low pass filter (no gains or mute)
new picks - processing based on picks with low pass offline filter.
Text file of knudsen picks.
Text file of sioseis picks.
Go to the list of seismic processes.
Go to SIOSEIS introduction.
Go to SIOSEIS examples.