Title: GeoPairingBased Engagement Simulation for ShoulderFired SurfacetoAir Missiles
1Geo-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
2Outline
- Types of Simulation and applicability of this
technology - GPS-based Geo-Pairing
- Stinger Geo-Pairing Device (GPD)
- Test Data
- Results
- Conclusions and Future Efforts
3Principal 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
4Principal 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
5Geo-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
6Geo-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)
7GPS-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
8GPS-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
9Stinger 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
10Stinger 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
11Stinger Geo-Pairing Device
12Stinger 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
13Test 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
14Stinger GPD Static TestVary Azimuth
15Stinger GPS Static TestVary Elevation
16Stinger GPD Static TestAzimuth Noise
17Stinger GPD Static TestElevation Noise
18Stinger GPD Dynamic TestAzimuth vs. Time
19Stinger GPD Dynamic TestElevation vs. Time
20Results
- 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
21Results (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
22Conclusions 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
23Conclusions 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
24Conclusions and Future Efforts (concl.)
- Technical enhancements to include
- Additional aiding devices
- Instrumentation hardware alternatives
- Real Time Casualty Assessment (RTCA) alternatives
for training applications