Table 3.
Detection ratios along the trajectory, calculated by comparing the numbers of detected Bluetooth phones with visual spectator counts from video recordings. The two greyed out rows represent abnormally high detection ratios and can be regarded as outliers. The bottom part of the table shows the average detection ratios, standard deviations and relative standard errors with and without pruning of the outliers.
| Number | Duration (s) | Distance (m) | Visual count (-) | Detected phones (-) | Detection ratio (%) | Average (%) | St. dev. (%) | Rel. st. error RSE | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 447 | 3,730 | 1,984 | 253 | 12.75% | 14.3 | 3.9 | 27.3 | average detection ratio based on all measurements |
| 2 | 527 | 4,246 | 1,350 | 153 | 11.33% | 13.0 | 2.3 | 17.9 | average detection ratio with measurements 6 and 9 pruned |
| 3 | 1,035 | 11,694 | 4,567 | 580 | 12.70% | 11.0 | 1.8 | 16.4 | reference detection ratio from literature [8] |
| 4 | 286 | 4,909 | 1,919 | 313 | 16.31% | ||||
| 5 | 144 | 3,148 | 1,013 | 116 | 11.45% | ||||
| 6 | 143 | 1,729 | 1,034 | 220 | 21.28% | ||||
| 7 | 358 | 4,479 | 1,502 | 154 | 10.25% | ||||
| 8 | 439 | 5,925 | 4,183 | 515 | 12.31% | ||||
| 9 | 275 | 2,777 | 1,207 | 273 | 22.62% | ||||
| 10 | 261 | 2,547 | 1,320 | 175 | 13.26% | ||||
| 11 | 143 | 1,755 | 1,758 | 209 | 11.89% | ||||
| 12 | 156 | 1,691 | 970 | 141 | 14.54% | ||||
| 13 | 152 | 2,442 | 808 | 90 | 11.14% | ||||
| 14 | 123 | 1,155 | 496 | 91 | 18.35% |