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

0.004687 seconds ahead of the NTP time pool. The global minimum (lag) time offset observed
by the SEAAR2l DRP over the full week was 0.003819 seconds behind the NTP time pool.
We then calculated the worst-case maximum temporal misalignment between the SEAAR2u and
SEAAR2l radars over the full week as the greatest spread between global maxima and minima
timestamps over the entire week. This maximum temporal misalignment can be expressed as the
greater of the following two differences:
Expression 1: (SEAAR2u global maximum offset) – (SEAAR2l global minimum offset)
Expression 2: (SEAAR2l global maximum offset) – (SEAAR2u global minimum offset)
Table 6-36 summarizes the result of each expression:
Table 6-36. Maximum temporal misalignment calculations.
Expression
Global Maximum
(seconds)
Global Minimum
(seconds)
Difference
(seconds)
1 0.017494 -0.003819 0.021313
2 0.004687 -0.008316 0.013003
Table 6-36 shows that the maximum temporal misalignment over the full week was 0.021313
seconds, which is well below the target threshold of 5 seconds for Performance Criterion PD4.1.
Conclusion
Performance Criterion SD4.1 was successfully demonstrated: The temporal misalignment in the
time references of two independent radars with overlapping coverage remained well within 5
seconds over a full week of continuous operation. The maximum misalignment was found to be
0.021313 seconds.
6.5.1.3 Data Fusion [SD5.1]
Objective
Our objective when designing Performance Criterion SD5.1, Near-Real-Time Fusion of Tracks
from Two Radars with Overlapping Coverage, was to demonstrate that fusion algorithms used in
the avian radars being evaluated by the IVAR project can be applied in near real time and
presented in a single operator display (i.e., COP) that shows duplicate tracks consolidated, and in
the process provides greater track continuity for targets moving from the coverage volume of one
radar to the next.
This demonstration uses bird track data recorded at three demonstration locations: SEA,
MCASCP, and NASWI. Two radars with overlapping coverage are operating at each of these
locations. We selected a total of five paired datasets from these sites in the analysis and used the
Accipiter® Radar Fusion Engine (RFE) to apply fusion processing on each paired dataset, as
well as to display the resulting tracks using its built-in COP display.
We established as the success criterion for this demonstration that the RFE processing time for
each paired dataset must be less than the respective actual time interval associated with that
dataset.
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