Antoine de SaintExupery:

1
Antoine de Saint-Exupery Perfection is reached,
not when there is no longer anything to add, but
when there is no longer anything to take away.
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
2
What is Phoenix ?

• The new DFS Tower Radar Display
• Single Model KF Multi Radar Tracker with-
  central track file- plot fusion- no mosaicing
• Two server, two LAN redundant architecture
• Remote Radar display with 9600bps link
• Using Linux on PC-Hardware, written in C
• Capacity 30 sensors, 2000 tracks

DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
3
Phoenix - Designer's Experiences

• What the measurement transformation has broken,
  the filtering can not fix.- cheap transformation
  approximations deliver biased transformed
  measurements to the filter
• A minimum number of statistical variables for a
  maximum position accuracy- model determination
  needs information that is taken away from
  position accuracy.
• There is always one more bug

DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
4
Phoenix Design decisions

• Use all measurements
• Use high quality Measurement transformation
• Only use ellipsoid validation gate
• Use low CPU-load Kalman Filter with- coupled x,
  y axes, uncoupled z axis- no acceleration state
  variable
• Track every target
• Display always Track position
• Minimize Server to Server communication

DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
5
Phoenix 42 Dimension Kalman Filter
State vector X, Transition matrix F, State
Covariance matrix P
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
6
Phoenix Slant Range Correction
Circular Earth Model Distance over ground s range
r, Target Altitude Hc Sensor Altitude Hr Earth
Radius Er
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
7
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
8
Phoenix Measurement transformation
Plot position in system coordinates xr, yr Sensor
position in system coordinates x, y Plot position
in measurement coordinates r, q Meridian
convergence g, length distorion m Target Altitude
Hc, Sensor Altitude Hr
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
9
Phoenix Meridian Convergence
Stereographic projection of northern hemisphere
with point of tangency 50N, 10E North on
the map is longitude dependent
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
10
Phoenix length distortion compensation
Differences projected distances to great circle
distances (mid-latitude) for Germany area Left
no length distortion compensation m Right with m
(Distortion in cm per projected km)
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
11
TE Infrastructure for statistical Evaluation of
ATC systems
Simulated Radar or Track data from AFS
ATC System under test like Phoenix
Radar/Track Playback AMOR/RAPS
Statistical Tool for Track/Radar quality
control SAS
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
12
Phoenix Evaluation results
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
13
Phoenix failed evaluation detail
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
14
Phoenix failed evaluation target path
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
15
Phoenix measured performance with Germany live
traffic

• 650MHz PC13 Radars, 550 Tracks -gt 12 CPU
  load30 Radars, 830 Tracks -gt 28 CPU load
• 2GHz PC13 Radars, 550 Tracks -gt 7 CPU load30
  Radars, 830 Tracks -gt 15 CPU load
• O(n) for track to CPU load much better than n2

DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian
16
Phoenix -Conclusions
System Evolution Primitive fixed gain
filter Complex interactive multi model
filter Simple single model filter To be
done Sensor weather channel display Minimum
safety altitude warning (MSAW) More integration
with flight-plan systems Better tracking of dim
targets and, and, and...
DFS Deutsche Flugsicherung GmbH, TWR/T-FRA, Andre
Adrian