Automatic Rejection of Noise
Noise from mechanical sources and rock falls from ore-passes are typically recorded at mines. These types of ground vibrations can add to the work load of data which needs to be manually processed but do not add value for seismic analysis and interpretation. The ideal is not to record these in the first place but as this is not always possible, the objective is to automatically remove these events from the database.
Without auto-picking, the available information for discrimination is:
- number of triggers
- trigger times
- sensor positions
- trigger duration
- maximum amplitude
- dominant frequency
Combining some of these parameters may give patterns which match mine operations, for example trigger time and sites triggered may match the time and location of working ore-passes. Rock-falls could also be identified by looking at the combination of dominant period and maximum amplitude as these are typically low frequency and do not generate high ground motions.
These auto-rejection parameters can be calibrated per mine and used to filter events as they are brought into the database.