Forward Analysis

Grid & Plane Setup window

The first step is setting up your Grid and plane you want to use for the analysis. Follow the link here on how the window works.

Current Sensors window

This window allows users to tick which sensors are currently active and should be used in the analysis. A 3D view is also shown to display the current sensors which are colored based on if they are active or not.

Selecting and visualising current sensors to use in sensitivity assessment

Add sensors window

This window allows new sensors to be added to the seismic system to see how the sensitivity improves in that area of the mine.

To add a new sensor, go to the Planned Sensors table and :

1. Thick the Edit box and insert a new row.
2. Input the required information in each column.

Adding new sensor

The system sensitivity can then be visualised in the 3D view. The surfaces or points can be colored by sensitivity, distance to furthest sensor required to detect an event, or the improvement to the sensitivity or distance.

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Using the Sensors series in the 3D view, you can colour the sensors by Planned vs Current to highlight the new sensors.

Additional tools in the window

There are Analysis controls, Grid controls, Plane controls panels to help quickly modify information. The number of sensors needed to process an event is set in the Analysis controls panel.

There is a Grid Results table that can be exported to display the results in other softwares.

The Current Sensors table can be accessed in this window.

Exclude sensors window

This window allows you to exclude sensors to evaluate the impact on the sensitivity in that area (if, for example, you lost a sensor or box). Simply tick a sensor in the Sensors to Exclude table to visualise the reduction in sensitivity and new sensitivity in the 3D view.

Excluding sensors and assessing the impact on the system sensitivity

Additional tools in the window

There are Analysis controls, Grid controls, Plane controls panels to help quickly modify information.The number of sensors needed to process an event is set in the Analysis controls panel.

There is a Grid Results table that can be exported to display the results in other softwares.

Assessing sensitivity using empirical method

Another way of assessing your system sensitivity is through an empirical approach. The principles on which the System Sensitivity Assessment is based, is described in part in the following papers:

Wesseloo, J. (2011) Empirical methods for assessment of seismic system sensitivity.Mining Technology, 120(2). http://dx.doi.org/10.1179/037178411X12942393517534

This paper can be downloaded from https://www.researchgate.net/profile/Johan_Wesseloo, or from https://uwa.academia.edu/JohanWesseloo

The preferred method of analysis of the mXrap team is using the GMPE based assessment (TODO LINK), however the empirical method allows for independent verification and assessment for cases where a calibration has not yet been done for the mine.

Further development was done after the publication of the paper, however, the main principles remain the same. First, the number of sensors needed to process an event is set, then the distances between the events in the database and the furthest sensor needed to detect the event is calculated.These events are then placed into bins based on the distances and plotted in a frequency-magnitude chart, allowing to calculate the $M_{min}$ for each bin. A distance to $M_{min}$ relationship can then be calculated and plotted on a grid to show the sensitivity across the mine. The Empirical window will allow you to do just as such.