3 Electronic Attack Flashcards
Disruptive EA: How does Noise Jamming work?
We can increase the ambient noise in the receiver bandwidth so that the SNR becomes too low to allow detection.
Active vs Passive EA
Active: Emission of energy
Passive: No emission of energy
What is Disruptive EA
Increasing ambient noise to blind enemy radar
What are two requirements for joise jamming to work?
Directed at the enemy receiver’s antenna
Cover the enemy receiver frequency bandwidth
What is Burnthrough Range?
Range where radar echo becomes visible over the Jamming.
Below the Burnthrough Range, the (enemy) radar echo is visible.
After the Burnthrough range, the jamming signal is stronger than the radar return.
What are the components of the Jamming Equation?
Signal Strength S
Jammer Strength J (note that it is only one way propagation)
Signal to Jamming Ratio
Spot Jamming
Barrage Jamming
Swept Spot Jamming
What is the tradeoff relevant to Jamming?
Power vs. Bandwidth
You need to spread your power accross the bandwidth to be effective over that frequency range.
Jamming Tactics: Self-Screening
A single aircraft must both jam and attack. Power must be distributed between the two.
Jamming Techniques: Escort
A more specialized aircraft may be used which is equipped specifically for jamming. More power can be used for jamming.
The Jammer is with the group for a balance between Stand-ff and Forward Deployed.
Jamming Tactics: Stand-Off
Jammer is behind the attack aircraft to remain safe. But it has less jamming signal strength.
Jamming TacticsL Forward Deployed
The Jammer aircraft is forward to increase the jamming power. But the aircraft is more vulnerable.
What is Deceptive EA? What are 3 methods?
Multiple Target Generation
Range Deception
Angle Deception
Range Gate Pull-Off (RGPO) with diagram.
Inverse Gain
Sends out jamming pusles in-between incoming pulses, which cause a constant gain at the enemy receiver. This makes it appear as though it is on target.
Cross-polarization jamming
The jammer take the incoming pulse, flips the polarization, and sends it back out. The cross-polarized pulses appear as false lobes, making it appear at a different angle.
Downside is it requires a lot of power at the transmitter to appear the same power level at the receiver due to the cross-polarization.
Cross-Eye
Sends two signals which are phase shifted IOT create a null in the direction of own self and constructive signal in another angle from the receiver.
Requires two separate antennas
Decoys: Confusion
Employed during the search phase.
Used to deny accurate bearing and range information
Decoys: Destraction
Used when missile is in-flight but not locked on
Provides an alternative for the missile to lock-on to.
Decoys: Seduction: Dump
(Chaff + Decoy)
Aim is to break missile lock
Used with RGPO
Decoys: Seduction: Centroid
Chaff deployed all around the ship to create a much larger target.
By the time the missile intercepts, the ship will have moved away and the missile will track the largest RCS which is the chaff cloud.
