Documentation of the Evaluation of CALPUFF and Other Long ...

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Figure 6‐6. False Alarm Rate (FAR) statistical performance metric for the five LRT models and
the ETEX tracer field experiment.
The Probability of Detection (POD) performance statistic is defined as the percent of the time
the predicted and observed tracer both occurred at a monitor‐time (i.e., a hit of tracer
concentrations greater than 1 ngm ‐3 ) divided by the number of times that the tracer was
observed at any monitor‐time (i.e., sum of hits and misses); a perfect model POD score would
be 100% (i.e., anytime there was observed tracer at a monitor there was also predicted tracer
at the monitor).
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False Alarm Rate (FAR)
(Perfect = 0%)
CALPUFF SCIPUFF HYSPLIT FLEXPART CAMx
Probability of Detection (POD)
(Perfect = 100%)
CALPUFF SCIPUFF HYSPLIT FLEXPART CAMx
Figure 6‐7. Probability of Detection (POD) statistical performance metric for the five LRT
models and the ETEX tracer field experiment.
The Threat Score (TS) is the ratio of the number of times that a tracer is both predicted and
observed at a monitor‐time at the same time (i.e., common hits among the predictions and
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