Topic:
How to find 'spikes' in seismic data, and get rid of them.

Description:
        

Solution:
Generate 'Mappable Seismic Statistics' of 'RMS amplitude'.

To find the spikes:
===================
1.) Application > Computation Manager > 'OK'.
2.) Survey > Select Survey and Input/Output Class > 'OK'.
3.) Select 'Mappable Seismic Statistics' from list of Available operations.
4.) Select RMS amplitude from the Statistics list, then 'OK'.
5.) In the Computation Manager window press the 'Start' button.
6.) On completion, go to Basemap > Post > Interpretation.
7.) Post horizon 'linevolume_stat' with attribute 'rms_class_name'. 
    Spikes should be detected using the color spectrum.

To Null the traces:
===================
1.) Application > DataManager > Seismic > Copy.
2.) Select Survey, Input class and toggle the Option button to 'Null data'.
3.) Click 'Change Area' button, and set cdp(s) to be nulled > 'OK'.
4.) 'Generate'.

If there are too many traces to be nulled, you may want to reload the data
with clipping on.
 
Reload the data with clipping on:
=================================
1.) Application > DataManager > Load Seismic > Define input format. 

2.) Under the "Key parameter source" toggle CDP to 'Expression', even if it 
    is being read from the trace header.

3.) At the bottom of the 'Define shot point and CDP expressions' menu, after
    '--> CDP =' type in 'cdp' (not in quotes).

4.) Then, on the NEXT line, put 'editval(-100,100,0,0,10000,1)' (again, not 
    in quotes).

5.) Click 'OK', and then make sure you save the loading definition.
 
Setting up parameters as above clips any samples outside the range of -100 and
100 to 0, up to 10,000 samples.  Adjust these parameters as necessary for your
situation.

 



Last Modified on: 14-APR-99