tailieunhanh - STEALTH TECHNOLOGYSTEALTH TECHNOLOGY: A REVEALING

What is it? RADAR to detect position of objects. Counter measures 1. ECM ( . chaff cartridges) 2. Non ECM. Avoiding detection and innovating deception . RCS reductions, acoustics, thermal and other EM is it achieved. Absorbs radar waves or deflects to other directions. Minimizes heat and other emissions from engine and other spots. Makes difficult to detect except shape and edges maximum radio wave reflectors. The size of a target's image on radar is measured by RCS (σ ) For a square flat plate of 1m2 area, σ=13982 m2 at 10 Ghz. | STEALTH TECHNOLOGY: A REVEALING An investigative study on stealth technology. What is it? RADAR to detect position of objects. Counter measures 1. ECM ( . chaff cartridges) 2. Non ECM Avoiding detection and innovating deception . RCS reductions, acoustics, thermal and other EM emissions Examples F 117 B-2 Bomber F-22 Raptor( From YF 23 Platform) SR-71 Black bird HMS Helsingborg How is it achieved. Absorbs radar waves or deflects to other directions. Minimizes heat and other emissions from engine and other spots. Makes difficult to detect except closely. Smooth edges maximum radio wave reflectors. The size of a target's image on radar is measured by RCS (σ ) For a square flat plate of 1m2 area, σ=13982 m2 at 10 Ghz Vehicle shape and structure Mainly plan form alignment. The leading edges of wing and tail surfaces set at same angles. Vehicle structure (contd) Use of re-entrant triangles behind skin. Distinctive serrations used in external airframes. Propulsion subsystem shaping. Now in research is fluidic nozzles for thrust vectoring. Vehicle structure (contd) Radar Absorbing Materials (RAM) RAMs often as paints used to absorb RADAR signals. Iron ball paint, ferrite in polymer matrix used. The cockpit canopy coated with thin layer of indium tin oxide . Small cell foams painted or loaded with absorbing ink. MAGRAM R- Card Absorbing honeycomb Transparent RAM RAMs (contd) Other fields Reducing RCS alone not enough. More difficulty is reducing the IR signature. Interest is near IR region. (shorter than 10 µm) Major IR emission sources. 1. Tailpipe region 2. Turbojets have EGT’s of 1000oC 3. Exhaust gas plume 4. Hot engine parts 5. Aircraft skin (frictional heating) 6. Reflected and reemitted sunlight. IR Emission IR Reduction Using surface paints Non circular tail pipe Emissions from hot parts screened by airframe. The plume mixed with cool air. IR best transmitted , 4 and 10 micron bands. IR outside window absorbed by CO2 Passive IR target acquisition . | STEALTH TECHNOLOGY: A REVEALING An investigative study on stealth technology. What is it? RADAR to detect position of objects. Counter measures 1. ECM ( . chaff cartridges) 2. Non ECM Avoiding detection and innovating deception . RCS reductions, acoustics, thermal and other EM emissions Examples F 117 B-2 Bomber F-22 Raptor( From YF 23 Platform) SR-71 Black bird HMS Helsingborg How is it achieved. Absorbs radar waves or deflects to other directions. Minimizes heat and other emissions from engine and other spots. Makes difficult to detect except closely. Smooth edges maximum radio wave reflectors. The size of a target's image on radar is measured by RCS (σ ) For a square flat plate of 1m2 area, σ=13982 m2 at 10 Ghz Vehicle shape and structure Mainly plan form alignment. The leading edges of wing and tail surfaces set at same angles. Vehicle structure (contd) Use of re-entrant triangles behind skin. Distinctive serrations used in external airframes. Propulsion subsystem shaping. .