Table 1 Previous analyses of long-term datasets that have used automated algorithms to detect calls and report spatial distribution and/or temporal occupancy of Antarctic blue whales.
Study | Detection method (software used) | Noise pre-processing | True positive rate | False positive rate | False positive removal | Characterisation/validation summary |
|---|---|---|---|---|---|---|
Širović et al. 200417 | Spectrogram correlation (Ishmael) Energy sum (Ishmael) | Not reported | Not reported | < 1% | No | Threshold was iteratively adjusted until false positive rate was < 1%. Calls on days with fewer than 50 detections were inspected |
Širović et al. 200918 | Spectrogram correlation (Ishmael) | Not reported | Not reported | Not reported | All | Visual inspection of all detections to remove false positives |
Samaran et al. 201330 | Spectrogram correlation (XBAT) | Not reported | Not reported | 6%a | Some | Months with fewer than 50 detections: visual inspection of detections to remove all false positives. Otherwise 10% of randomly selected detections inspected |
Tripovich et al. 201520 | Energy detection (Ishmael) | Not reported | Not reported | 14.6% | All | Visual inspection of all detections to remove false positives |
Thomisch et al. 201619 | Spectrogram correlation (custom developed) | Not reported | Not reported | Nominally < 1% | No | False detection rates and thresholds determined via detection function quantiles from 100 randomly selected detectionsb |
Leroy et al. 201626 | Subspace projection detection36 | Noise-adaptive threshold | Not reportedc | Nominally < 3% | Some | Detections deemed false if the frequency at maximum amplitude was different than that of unit-A |
Balcazar et al. 201745 | Energy sum (Ishmael) | Not reported | 93.3–97.3% | 14.6–98.9% | All | Comparison against expert human observer who annotated 1 randomly selected day each month for each site. Visual inspection of all detections to remove false positives |
Buchan et al. 201742 | Spectrogram correlation (Ishmael) | Not reported | 99.998%d | Not reported | All | 20% subset of days with no automated detections visually inspected to determine false negative rate. Visual inspection of all detections to remove false positives |
Shabangu et al. 201716 | Spectrogram correlation (XBAT) | Not reported | 42–83% | Not reported | All | Visual inspection of entire dataset (1518 h) to assess remove false positives and include missed detections |