Missiles

1. Missiles Rebecca Lucast

2. This is what I am going to talk about • Theory of missile guidance systems • Different kinds of systems and the weapons they support (shorter range than intercontinental) • Specific guidance that uses radar and how it does so • Applications: Star Wars

3. Theory of Missile Guidance

4. Different Types of Systems • Beam Riding • Command Guidance • Navigation • Inertial • Ranging • Celestial • Geophysical • Homing • Passive • Semiactive • Active • Retransmission

5. Beam Riding • Outdated technology, in use in the 1950s • Target painted by tracking beam, which missile would follow • Computer calculated where missile was in beam to keep it aimed to target • Poor at longer ranges

6. Command Guidance • Like Beam, needs external targeting radar • Tracks target and missile, sends information to missile to guide it into target • Can be radio- or wire-guided, as in TOW or submarine torpedoes

7. Navigation • Inertial– detect changes in position and movement • Ties into last week, right? • Ranging– GPS, airport beacons • Celestial– mapped stars like early explorers • Geophysical– terrain and digital scene matching

8. Inertial • Gyroscopes (mechanical and laser) and accelerometers monitor rotation and acceleration on the axes • Computer calculates changes to know position

9. Ranging • GPS triangulates position, compares to programmed target position • Like early explorers, keep track of position relative to known stars Celestial

10. Geophysical • Scene matching compares what missile “sees” during flight to programmed aerial or space photos • Course adjusted until pictures match • Tomahawk cruise missile guidance system • Terrain features programmed into missile • Radar altimeter to tell missile where it is

11. Homing Guidance • Passive • Locks onto signal given off by target, calculates relative position of target, guides in • Can be heat signal, instrument noise, sound, or a visual image of target • Air-to-air, air-to-surface, and other missiles • Sidewinder and HARM weapons

12. Homing Guidance • Semi-active • Missile detects reflected signal broadcast by targeting radar • Calculates relative position of target, guides in • Sparrow and Paveway • Paveway are laser guided, not radar • External laser beam from air or ground reflects from target to incoming missile

13. Homing Guidance • Active • “Fire and Forget” • Missile broadcasts own targeting radar • Detects reflection, guides into target • AMRAAM and Exocet weapons

14. Homing Guidance • Retransmission • Similar to command guidance in that missile does not “think” • Missile detects reflection, sends information to tracking computer • External computer sends course-correction controls back to missile • Need reliable communication back to missile • Patriot missile system

15. US Missile Defense System “Star Wars” • Ground-based radar to detect launch of enemy missile • Follow path, distinguish from false targets • Transmit data to friendly intercept missile to guide it into target • Completely destroy enemy missile in the air to prevent possible ground contamination?

17. Acknowledgements • www.HowStuffWorks.com • www.aerospaceweb.org for diagrams, overview • http://www.defenselink.mil/specials/missiledefense/nmd.html • http://www.acq.osd.mil/mda/mdalink/pdf/bmdsbook.pdf for missile defense diagram