LO Principles Flashcards
Stealth reduces __________
Active and passive signatures
Objective of stealth
Reduce the probability of detection
Active signature examples (3)
RF Signals: comm, navigation, radar
Acoustic: engine noise, prop noise
Infrared: engine exhaust, skin temp
Passive signature examples (2)
EO/Visual
EM (radar)
Radar signature is dominated by………
Shape
Why is RCS the most critical signature of most aircraft?
Radar provides all weather, long range detection capability (**provides early warning)
Radar provide target range, azimuth, and velocity data (**provides tgt tracking)
Stealth is enhanced by …. (3)
Forcing Threats to use active sensors sparingly
Using intel data to minimize onboard active and passive sensor exposure
Use tactics that combine w/ order of battle as well as man made environment
Radar signature is expressed as aircraft…….
RCS
Define RCS and explain the factors that determine its size
The measure of a targets ability to reflect RF signals in the direction of the radar receiver
Factors: Azimuth Elevation Frequency of viewing radar Polarization of viewing radar
List 4 basic methods to make an aircraft stealthy
Shaping (by far the most important)
Absorption
Cancellation
Transparencies
Describe shaping
Reflect radar energy into any direction other than back to the radar site
Describe absorption
Utilize RAM to turn radar energy into heat
Describe cancellation
Actively or passively reflected radar waves add together to cancel each other out
Describe transparencies
Allow radar energy to pass thru the material w/ minimal reduction in energy or change in wave characteristics
Describe faceted shaping
Orient flat surfaces to deflect radar energy away from threat radar
Describe compound curve
Replace straight edges with curved edges to reflect less radar energy towards threat radar
Describe planform alignment
Return a radar signal in a very specific direction away from the radar emitter
Goals of radar absorption materials
Reduce specular and multibounce reflections
Reduce energy diffracted from trailing edges or discontinuities by absorbing energy as the wave travels along the surface
Characteristics of E-RAM
Narrowband
Thick, but light
Characteristics of MagRAM
Broadband
Thin, but heavy
Characteristics of large volume RAS
Broadband
Thick, but light
How does the aircraft surface breaks and gaps affect total RCS
Residual reflections are caused by surface discontinuities
Engine inlet design methods used to reduce RCS
Screen grids
Buried engines
Intakes on top
Canopy design methods used to reduce RCS
Made of radar absorbing materials
Smoothly blended into aircraft
Shape deflects radar away
Other methods used to reduce RCS
antennas
Windows for sensors
Air data sensors
Access doors
External stores
List 4 basic systems used to counter stealth
Low freq radar
High freq radar
Bi/multi static radar
Passive coherent radar
2 limitations of low freq radar
Few frequencies available and heavy clutter
Poor range resolution
2 limitations with high freq radar
Short range
Atmospheric attenuation
2 limitations with bi/multistatic radar
Synchronization
Widebeam antenna or long scan time
2 limitations of coherent radar
Reliance on third party illuminators
Azimuth/range only
discuss mx practices that assure LO properties
Mx tracking records
Visual inspections
True RCS measurements
Diagnostic imaging
Elements that contribute to Cost of stealth
Cost per flying hr
Acquisition cost
Infrastructure cost (security, support, etc…)
Inspection cost
Personnel cost
What is the value of stealth
- provides a method of breaking the kill chain
Discuss limitations of stealth
Operating cost
Limited number of assets
Complex MSN Planning
Lacks flexibility
Threats
