AwSim™ Metrics
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The AwSim metrics tools consist of two separate
applications - the Sector Analysis Metrics tool (SAM) and
the Statistical Analysis Tool (SAT). SAM is the main metrics
computational engine and provides the input to SAT. SAM is a
metrics based statistical analysis software tool designed
for air traffic analysis and systematic measurements of
airspace configuration. The metrics tool evaluates various
airspace utilization parameters on a sector and gate basis
giving a direct measurement of sector load, configuration
efficiency and traffic pattern complexity under different
traffic pattern arrangements and airspace configurations.
The measurements done by the metrics tool rely on a
partition of the airspace into regions, which may or not be
coincident with ATC sectors, and gates based on the needs of
the user. For each one of these regions and gates (when
applicable) the program computes the following sets of
metrics:
- Sector load metrics
- Sector 'busyness', traffic density, number of conflicts and conflict characteristics
- Sector efficiency, excess distance, fuel burn, time of flight, delays, etc
- Trajectory and traffic patterns
The Statistical Analysis Tool (SAT) is an application that
compares two data sets by means of standard statistical
tests. In principle SAT can compare any two data sets
regardless of their origin or meaning. As primary input SAT
accepts the raw metrics files written by SAM. SAT computes
statistics that compare the actual distributions, the mean
values and the variances of the input data sets. Pair-wise
and population-based statistical tests are supported. SAT
used in conjunction with SAM provides the means to perform
systematic comparisons of any two-simulation experiments,
which could be the result of two AwSim runs with different
input data-sets or two runs with the same input data but at
different stages of processing. SAT produces a log with the
results of the statistical tests comparing each metric for
each airspace involved in the simulation (as seen in the
sample below).
============================================================================
METRIC: Excess distance
============================================================================
Group Mean Sigma Min Max Npnts
----- ---------- ---------- ---------- ---------- -------
1 350.6 369 0.2679 2331 48961
2 352.4 366.4 0.2679 2247 47488
Delta 5.848 12.66 -24.86 266.5 46051
NORMALITY TESTS
Group Median Mode Skewness Prob Kurtosis Prob Chi2 DOF Prob
----- --------- --------- -------- ---- -------- ----- --------- ---- ----
1 207.5 54.65 175.1 0 177.4 0 5.702e+04 147 0
2 211.4 67.67 170 0 168.5 0 5.415e+04 147 0
Delta 1.258 -0.5792 442.6 0 1869 0 1.137e+05 147 0
COMPARISON TESTS
Test Value Prob DOF1 DOF2/SErr
--------- --------- --------- --------- ---------
chi2 151.2 0.3042 143
F 1.014 0.1303 4.896e+04 4.749e+04
Z -0.7827 0.4338 2.368
T-Eq -0.7826 0.4339 9.645e+04 2.368
T-Uneq -0.7827 0.4338 9.639e+04 2.368
Z-Pair 99.16 0 0.05897
Sign 1880 0 4.455e+04
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Sample SAT output
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