Advanced Data Analysis Introduction
Because of the potential for false positives accompanying the fluorescence response of the target analytes when using laser induced fluorescence technologies, the practitioner is required to use multiple lines of evidence to “ground truth” the waveforms observed in the LIF logs. This requires consideration of as many elements as possible and can include historical evidence of releases, previously obtained drilling information, co-sampling alongside LIF logs, careful examination of the cores, and (if possible) application of soil core materials back onto the LIF instrument for direct reading above ground.
Dakota works with our clients in real time to categorize the waveforms into known and unknown fluorescence sources and to identify logs and certain depth horizons that appear to represent general classes of fluorescence observed. Several unique classes of waveforms may be observed at a site, indicating a degree of heterogeneity of subsurface fluorescent materials.
See the Methods description for details about a recently developed classification or “clustering” analysis method that is the fastest method we have found to quickly survey for similarities and/or differences in waveforms among the various logs and/or differing response horizons within single logs.