April 14, 2004 Chris Geswender cegeswender@raytheon Andy Hinsdale

1. Presentation to 39th AnnualGun/Ammo & Missiles/Rockets ConferenceDeconstruction of Fuze Well Guidance Requirements April 14, 2004 Chris Geswender cegeswender@raytheon.com Andy Hinsdale Andrew_J_Hinsdale@raytheon.com

2. Synthesis of Course Correcting Fuze Design • Corrects major errors including • Inherent Gun laying errors • Muzzle Velocity Variation • MET errors Determine best Solution Space to developing a fuze well based guidance package to provide first shot accuracy < 50 meters

3. Derived Requirements • Increase effectiveness and efficiency of cannon artillery • CEP<50 meters • Reduce logistics • Increase OPTEMPO • Exploit large existing projectile war stocks • Fuze well implementation • Reversionary mode (fuze only) • Corrector must still be a fuze • Easy to install, program, and be robust to field handling • Volume for fuze functions • Must have a reversionary mode • Cost << $5000 1DOF Unguided 2DOF 3DOF-7DOF

4. ACCURACY Definitions RANGE (Dispersion) } Precision Error(Deflection) Mean Point of Impact (MPI) RANGE Bias Error Mean Point of Impact (MPI) } Precision Error(Range) (Dispersion) Target Center DEFLECTION DEFLECTION Bias Error Mean Point of Impact (MPI) • Range errors dominated by • Muzzle velocity variation • MET • Deflection errors dominated by • Gun Laying errors • MET Gun Target Line(GTR)

5. Wide Potential Solution Space Alternate Concepts Number of known concepts 1DOF- Downrange 1DOF- Cross range 2DOF-Decoupled Roll stabilized Roll rate Stabilized 2DOF-Body fixed Roll Rate/Aerobrake (1+) Flow disruption HF Fixed canard HF trailing canard / solenoid ? ?

6. Some Examples 1DOF Range Correctors STAR SPACIDO DMS 2DOF Range/Deflection Correctors 1DOF Deflection Corrector MIT Concepts NSWC GIF CMATD ANSR

7. Theory of Operation - 1DOF-R Minor modification to firing tables required (range and deflection) Projectile acquires “truth” of its position and estimates impact Projectile determines best point for high drag trajectory to impact Projectile initialized and fired “over” target Projectile deploys aerobrakes

8. Theory of Operation - 2DOF Projectile acquires “truth” of its position and estimates impact Projectile deploys aero surfaces Projectile initialized and fired at target Projectile determines best point for start guidance Projectile continuously corrects impact Requires no modifications to firing tables

9. Theory of Operation - 2DOF Control Projectile (12) W ( rotation ) (13) Out of plane force V ( linear motion ) (14) Mass Velocity Fc ( coriolis acceleration ) (15) Rotation Spin Stabilizing Rotation No Rotation Aerodynamic Force Vector Aerodynamic Force Vector Body Rotational Moment Body Rotational Moment

10. Potential “truth” sources for Guidance • Ballistic • Inertial • Data Link Update (Command) • GPS • Ground Beacon Array • Terminal Seeker • (seeker range, packaging, costs issues)

11. Maximum range LOS altitude Beacon siting error Beacon NORTHing error Beacon signal errors - range noise Beacon signal errors - angle noise Corrects Gun- Laying angle errors Corrects gun NORTHing error Corrects Muzzle exit velocity errors All-weather Integration Challenges Unit Cost Sensitivity - Countermeasures Compatible to moving targets Radiating Shooter Summary of “Truth” Sources for Guidance Seeker Command (PTS) Ground Beacons GPS / IMU Ballistic Inertial Beacon Error Sources Platform error corrections Operational Considerations Technical and Cost Considerations GPS or GPS/INS Appear to be Most Appropriate Truth Sources

12. Representative 2DOF Fuze / Guidance Kit Stowed Aero Surfaces Battery Primer Booster FS&A Electronics Fuze Actuators

13. Various Studies Have ShownConcept Feasibility Wind 10% 10% 33% 33% 67% 67% 100% Canard 0.25 0.25 69 69 74 87 0.5 0.5 25 33 51 96 1.0 1.0 4 9 19 51 2.0 2.0 2 2 4 18 4.0 4.0 2 2 2 5 6.0 • Various CCF/GIF Studies have indicated sufficient Maneuverability with Low aerodynamic effect lifts. • However, these studies widely vary as to real life implementation fidelity (winds aloft / guidance law interaction, guidance start times, actuation constraints) • Without considering realistic winds aloft many control concepts will appear satisfactory • But due to physics of the spinning projectile there is a practical limit to useful CL authority CL~.02 CL~.015 Reference –Aerodynamic Fuze Characteristics A.M. Budge June 1998 MIT

14. Representative Winds Aloft Surface 3,000 ft 12,000 ft 30,000 ft

15. GIF/CCF Requirements Deconstruction NATO STANAG Compatible Concepts 1D-R 1D-D 1D+ 2D 3D 4D 5D 6D 7D Can Correct Trajectory Dispersion 1D-R 1D-D 1D+ 2D 3D 4D 5D 6D 7D Can Correct CEP <50m 1D+ 2D 3D 4D 5D 6D 7D Fuze Well Compatible 1D+ 2D 3D Can Cost < $5K 1D+ 2D 3D HIGH GPS AJ capable A/J capable with no special handling 1D+ 2D 3D

16. Summary • Depending on desired Operational Flexibility and Cost Sensitivity, there are a number of potential solutions. • Spiral development from the 1DOF (presently easily implementable) to the final desired operational product (2DOF or 3DOF) is an option • GPS or GPS/INS are the most appropriate “truth” sources • Joint service kit requires 2DOF or 3DOF kit at minimum • To avoid developing new ballistic tables, nose weight/shape should conform to NATO STANAG OML • Implementation of actuation and power source are the technical challenges • Packaging of a gun hardened unit is also a challenge