Amplitude Clipping - Log Transform

  

This log transformation is available from the Advanced Transforms tool.

This transform tool:

  • Clips spikes in the data outside of a given minimum and maximum value.
  • Can replace a specific data value with a null.

Useful when curves contain non-standard null values (such as "-9999" or "0" instead of the more common "-999.25 ").  

Log To Clip

Selects the name of the log curve to be clipped.  

This option permanently changes the selected log curves, so it's usually best to retain a backup set of curves and perform this operation only on a set of copied logs.

Minimum Amplitude Allowed

Sets the lower limit for clipping.  Curve values below the entered value are clipped.  

The default value of -1E30 is so low that Petra will not perform a minimum clipping.

Maximum Amplitude Allowed

Sets the upper limit for clipping.  Curve values above the entered value are clipped.

The default value of +1E30 is so high that Petra will not perform a maximum clipping.

Set to NULL if log is equal to clipping.

Replaces a single value with a null value. All log values equal to the entered value will be converted to nulls.

This option is used to correct data that was imported with non-standard null values like "-9999 " or "0". This function can be used independently of amplitude

In the example below, the original curve is on the left and the clipped curve on the right.

The gamma ray values in the clipped curve above 200 API and below 0 have been replaced with null values.

Related Topics

Advanced Transforms