Full analysis consists of obtaining the transit time between the Vs waves from the top signal and proceeding towards the bottom. This is carried out through a algorithm called cross-correlation. SPAS 2009 uses an advanced cross correlation algorithm implementation based on the FFT and inverse FFT of the signals, reducing the time for this analysis dramatically.
Perform full analysis
The results of this procedure can be viewed when a signal depth is selected from the Reference depth list. A plot with the cross correlation results (transit time) over depth is created providing a visual interpretation of the amount of scatter. Scattered dots in this diagram can be reviewed by clicking on a dot. This will lead you back to the corresponding signal, which can be deleted or filtered. Each point in the plot represent a signal so identifying bad signals is quite easy. Clicking on the signal's point SPAS 2009 will identify the signal and return to the Field data tab area where that signal will be selected. Uncheck the signal from the list and it will not be included in any future calculation.
This figure shows a test in which the transit time plot shows very little scatter
This figure shows a test in which the transit time plot shows a lot of scatter