(IVAR) - Final Report - Strategic Environmental Research and ...

We extracted the radar data for this analysis from the plots and tracks files by constructing alarm
regions in the TrackViewer software and playing back the recorded data that corresponded to the
times of the Point-Counts. We labeled the alarm zones with the number corresponding to the
visual sampling Point-Count Circle to allow a comparison between visual counts and radar counts
for individual Point-Count Circles. The data were analyzed for times that corresponded
to the time the visual observer was at each Point-Count site and for all 12 Point-Count sites for
the time of the complete count block. Thus, there are two comparisons made: A 5-minute
synchronized comparison between visual observations and the radar, and a comparison for the
total (1-2 hours) period of the visual survey block between visual and radar.
Results
The mean numbers of birds seen on the synchronized comparison did not differ between the two
techniques: Visual = 1.78 birds/point count, Radar = 2.0 birds/point count; Student's t = -0.1127,
df = 44, P > 0.05.
Our comparison of the total number of birds detected per hour for the 12 sites for the total count
block demonstrated that the radar detected significantly more birds (mean = 97.3 birds/hour) than
the visual observer (mean flying past = 2.14 birds/hour; mean all flying = 7.06 birds/hour)
(ANOVA: F 2,51 = 37.4, P < 0.01).
There is an obvious inequality in comparing the number of birds observed for the duration of the
visual count block: An observer is at each of the 12 sites for 5 minutes but the radar is
monitoring all 12 sites during the same period of time. If the number of birds detected by the
radar is adjusted to a detection rate per 5 minutes (mean = 8.12) and compared to the visual
count (mean = 2.14; flying past), the radar still detected significantly more birds than the visual
observer (Student's t = -4.61, df = 17, P < 0.001).
The above comparison is not inconsistent with the results of the synchronized comparison. The
synchronized comparison included only point-count observations in which the visual observer
recorded birds “flying past.” The above comparison includes all Point-Count observations for
that block including the ones in which the visual observer did not record any birds as "flying
past" but the radar detected birds flying within the count circle.
Conclusion
The radar detects about 4-times as many birds as a visual observer for 5-minute synchronized
Point-Count observation periods. For an entire count block (1 hour of observation), the radar
detected about 50-times as many birds as a visual observer because the radar could monitor all
12 point-count sites simultaneously while the visual observer could monitor only one. Thus, the
Success Criterion for PB5.1 was exceeded in both the synchronized and the total time period
comparisons.
6.2.1.6 SAMPLES UP TO 3000 FEET [SB6.1]
Objective
More than 90% of all bird strikes occur below 914 m (3000 feet) above ground level (Dolbeer,
2006). Performance Criterion SB6.1, Samples to 3000 Feet, is a secondary criterion designed to
demonstrate that avian radar is capable of sampling birds at the upper end of this range. We chose
914 m (3000 ft) as the performance metric for a successful demonstration of this capability
150