Radar Jamming | What are type of Radar Jamming?

In this Lecture, we are going to learn about What radar jamming is? What are the types of jamming used in Radar?

What is Radar Jamming

RADAR JAMMING IS THE INTENTIONAL EMISSION OF RADIO FREQUENCY SIGNALS TO INTERFERE WITH THE OPERATION OF A RADAR BY SATURATING ITS RECEIVER WITH FALSE INFORMATION.

There are two types of Radar jamming:

1. Mechanical or passive jamming
2. Electronics or Active jamming

Mechanical or Passive Jamming

• Mechanical jamming is caused by devices that reflect or re-reflect radar energy back to the radar to produce false target returns on the operator’s scope.

• Mechanical jamming devices include chaff, corner reflector, and decoys.

Chaff:

• Chaff is made of different-length metallic strips, which reflect different frequencies, so as to create a large area of false returns in which an actual contact would be difficult to detect.
• Chaff is often aluminum for weight purposed and is usually coated with something such as plastic to make it slicker and less likely to bind up in large clumps.

Corner Reflector:

• Corner reflectors have the same effect as chaff but are physically very different.
• Corner reflectors are multiple-sided objects that reradiate radar energy. An aircraft can’t carry as many corner reflectors as it can chaff.

Decoys:

• Decoys are maneuverable flying objects intended to deceive a radar operator into believing they are actually aircraft.
• They are especially dangerous because they can clutter up a radar with false targets and neutralize making it easier for an attacker to get within weapons range.

Electronic or Active Jamming

• Electronic jamming is a form of Electronic attack where jammers radiate interfering signals toward an enemy’s radar, blocking the receiver with highly concentrated energy signals.

• The two main techniques for Electronic jamming are:

1. Noise Technique 
2. Repeater Technique

1. Noise Technique:

There are three types of Noise jamming are:

1. Spot Jamming
2. Sweep Jamming
3. Barrage Jamming

1. Spot Jamming:

• Spot jamming occurs when a jammer focuses all of its power on a single frequency.
• While this would severely degrade the ability to track the jammed frequency, a frequency agile radar would hardly be affected because a jammer can only jam one frequency.

2. Sweep Jamming:

• Sweep jamming is when the jammer’s full power is shifted from one frequency to another.
• While this has the advantage of being able to jam multiple frequencies in quick succession, t does not affect them all simultaneously, and thus limits the effectiveness of this type of jamming.

3. Barrage Jamming:

• Barrage jamming is accomplished by transmitting a band of frequencies that is large with respect to the bandwidth of a single emitter.
• Barrage jamming may be accomplished by presetting multiple jammers on adjacent frequencies using a single wideband transmitter.
• Barrage jamming is that multiple frequencies at once by a single jammer.  

2. Repeater Technique:

• Repeater Technique manipulates received radar energy and retransmits it to change the return that the radar sees.
• These techniques can change the range the radar detects by changing the delay in transmitting pulses, the velocity the radar detects by changing the doppler shift of the transmitted signal, or the angle to the plane by using AM techniques to transmit into the sidelobes of the radar.