28-12-2010, 05:13 PM
HRIDYA I & ATHUL AJITH
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What is it?
RADAR to detect position of objects.
Counter measures 1. ECM ( e.g. 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
Mainly plan form alignment.
The leading edges of wing and tail surfaces set at same angles.
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.
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
Other fields
Reducing RCS alone not enough.
More difficulty is reducing the IR signature.
Interest is near IR region. (shorter than 10 µm)
