GeoPairingBased Engagement Simulation for ShoulderFired SurfacetoAir Missiles

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Geo-Pairing-Based EngagementSimulation for
Shoulder-Fired Surface-to-Air Missiles
John W. Shockley john.shockley_at_sri.com 1-650-859-
4165
Virginia M. Gallagher virginia.gallagher_at_sri.com
1-650-859-6515
James Y. Gilkey jim.gilkey_at_sri.com 1-650-859-2917
01E-SIW-075
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Outline

• Types of Simulation and applicability of this
  technology
• GPS-based Geo-Pairing
• Stinger Geo-Pairing Device (GPD)
• Test Data
• Results
• Conclusions and Future Efforts

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Principal Types of Simulations

• Live SimulationReal People, Real Vehicles,
  Real Environment, Simulated BulletsExamples
• Combat Training Centers
• Air Ranges (Top Gun)
• DFIRSTTM
• Virtual SimulationReal People, Simulated
  Vehicles, Simulated Environment, Simulated
  BulletsExamples
• SIMNET
• CCTT
• Aircraft simulators

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Principal Types of Simulations (cont.)

• Constructive Simulation(Some) Simulated People,
  Simulated Vehicles, Simulated Environment,
  Simulated BulletsExamples
• Janus
• JCATS
• ModSAF/OneSAF
• All types have
• Advantages/disadvantages
• Types of training for which they are best suited
• Unique technical characteristics that govern
  operation and interoperability

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Geo-Pairing-Based Engagement Simulation
Error conefor DFIRST,half-angle is0.2 deg

• Shooter location and pointing angle target
  location defines shooter-target pairing
• One mechanism for simulating the bullets in
  Live Simulations, I.e., instrumentation systems

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Geo-Pairing-Based Engagement Simulation

• Currently used for aircraft and ground vehicle
  engagement simulations
• Air-to-air engagements
• Tank main gun, coax machine gun, and Bradley 25mm
  engagements
• Supports tank live-fire training
• Advantages over other mechanisms
• No detectors on targets
• Targets may be virtual
• Quicker installation
• Not subject to visual obscurants (e.g., smoke and
  dust)

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GPS-Based Geo-Pairing
To GPS Satellite i
To GPS Satellite i
di
WholeCycle PhaseDifference
FractionalCycle Phase Difference

Because antenna spacing is gt1 wavelength, phase
differences are ambiguous by a number of whole
cycles Process of determining whole cycle
values is referred to as ambiguity
resolution.

d

LAUNCHER TUBE


Angular accuracy gets better as d increases, but
ambiguity resolution gets harder.

GPS
GPS

RECEIVER
RECEIVER


Provides origin pointing angles for a
vectorthat is co-linear with launcher tube.

Fractional PhaseMeasurement
Fractional PhaseMeasurement


AMBIGUITYRESOLUTIONPROCESSING



POINTING ANGLECOMPUTATION

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GPS-Based Geo-Pairing

• Currently used on the Deployable Force-on-Force
  Instrumented Training System (DFIRSTTM) tank
  training system
• Gun barrel dynamics relatively constrained
• Low elevation angles
• For the Stinger application addressed here
• Less constrained dynamics
• Unconstrained in both azimuth and elevation

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Stinger Geo-Pairing Device

• Two Phase Project for US Army Air Defense
  Artillery Test Directorate (ADATD) to expand
  DFIRST geo-pairing technology to Stinger launcher
  for TE applications--Stinger Geo-Pairing Device
  (GPD)
• Phase I Feasibility Study--determine
  applicability of GPS-based pointing technology to
  shoulder-fired weapon
• Phase II Prototype Developmentdevelop ten
  prototype units for TE applications at Ft. Bliss

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Stinger GPD Requirements

• GPS-based azimuth and elevation at 10Hz data rate
• Azimuth0-360 deg 0.25 deg accuracy
• Elevation0-60 deg 0.25 deg accuracy
• Stinger launcher-mounted jig
• GPS antennas and mounting hardware 1lb.
• Minimize impact on user (e.g., visibility)
• Based on DFIRSTTM PIP
• Located 50 ft from launchercable to GPS
  antennas
• Power and Ethernet connection (for pointing data)
  available to PIP

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Stinger Geo-Pairing Device
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Stinger GPDTechnical Issues Addressed

• Increase in data rate from 1 Hz (DFIRST) to 10 Hz
  (Stinger)
• Used BAE Systems AllStar Receivers (10Hz output)
  vs. SuperStar Receivers (1 Hz)
• Verified capability of Geo-pairing software to
  provide data at 10 Hz rate
• Increased baseline to 1.39 m to take advantage of
  Stinger launcher length
• Used lightweight aluminum jig for mounting
  antennas
• Added clinometer to aid in reacquiring GPS
  pointing solution after loss of lock (Done after
  initial testing would likely be necessary if IFF
  interrogation jams GPS signals for 1s.)
• Used tilt-able ground planes to test best angle
  for all-aspect GPS reception

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Test Data

• Mounted antenna brackets to Stinger Field Head
  Trainer (FHT)
• Same size and weight as Stinger
• Lacks IFF electronics and missile launch/seeker
  capability
• Conducted static and dynamic tests
• Static testsprovided estimate of precision
• Dynamic testsprovided indication of tracking
  continuity
• Tests conducted on roof of 3-story building
• Favorable environmentno foliage and good GPS SV
  visibility
• Comparable to desert environment at Ft. Bliss

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Stinger GPD Static TestVary Azimuth
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Stinger GPS Static TestVary Elevation
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Stinger GPD Static TestAzimuth Noise
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Stinger GPD Static TestElevation Noise
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Stinger GPD Dynamic TestAzimuth vs. Time
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Stinger GPD Dynamic TestElevation vs. Time
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Results

• Successfully demonstrated GPS-based pointing of
  hand-held (shoulder-fired) launcher.
• Azimuth accuracy 0.25 deg. (est.)
• Elevation accuracy 0.5 deg. (est.) (vs. 0.25
  deg. desiredstill expected to be sufficient for
  ADATD needs)
• Demonstrated 10 Hz data rates
• Demonstrated 0-60 deg. all around elevation
  tracking

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Results (cont.)

• Stinger GPD accuracy sufficient for target
  pairing
• Error cone can distinguish air targets 100 ft
  apart at 2 mile range
• GPS-based position plus GPD target pairing is
  sufficient to determine launch conditions to
  initialize a missile flyout model

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Conclusions and Future Efforts

• Despite successful feasibility demonstration,
  program was halted due to shift in US Army
  priorities
• GPD capabilities demonstrated suggest
  considerable applicability for GPS-based pointing
  for the Stinger and similar weapons.
• Resulting error cone sufficient to distinguish
  air targets in close formation (100 ft at 2
  miles)
• Position plus target pairing supports
  initialization of missile flyout simulations

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Conclusions and Future Efforts (cont.)

• GPS-based Geo-Pairing provides improved
  capabilities for engagement simulation for Live
  Systems
• Not affected by smoke or other visible obscurants
• Extendable to other guided weapons?
• Consistent with live-virtual engagement
  simulation
• There is continuing interest from other services
  in the further development and fielding of a
  Stinger GPD
• National Guard
• Combat Search and Rescue (CSAR) Exercises

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Conclusions and Future Efforts (concl.)

• Technical enhancements to include
• Additional aiding devices
• Instrumentation hardware alternatives
• Real Time Casualty Assessment (RTCA) alternatives
  for training applications