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150 Advances in Productive, Safe, and Responsible Coal Mining

Fig. 8.36 Survey 1127.

Fig. 8.37 Survey 1130.

are significantly lower than target values for the tracking system. Along the entirety of
escapeways, the 90% CD should be less than 2000 ft and the average of both
escapeways is one quarter of this target. Both predicted and measured AA describe
a tracked device’s location within two crosscuts with two crosscuts of potential error
(SDA). A crosscut along the travel way (100ft) can be crawled in less than a minute
(34s assuming 3ft/s crawling speed), meaning a potential search area of 400ft can be
slowly traversed by a rescue team in 2–3min. These prediction results are only for
prediction locations that were visited by the survey buggy during one of the surveys
in the data set. This may lead to some inconsistencies with previously reported results;
however, values are of a consistent order of magnitude and indicate the importance of
the data set that is used to calculate these metric values.