Why no one take advantage of multipath return phenomenon for SEAD/DEAD

[Ronny]

The interaction between the ground bounce return and aircraft return create blind region where aircraft can’t be detected. The location of this region can be calculated based on height and frequency. So why it is not a common way to evade radar detection (unlike nap of the earth flight)

 

[Forest Green]

From a person on another forum.

The interaction between the ground bounce return and the aircraft return creates several blind regions where the aircraft cannot be detected. The location of these regions can be calculated based on height and frequency. But this is not a common way to escape radar detection because these areas do not form a continuum in which the aircraft can inscribe its trajectory, they are rather small discontinuous regions between which the aircraft will be detected: the radar will see a dotted trajectory that a good filter will be able to reconstruct completely.

Basically, it seems that the blind spots are not as nice and continuous as they appear in that diagram.

 

[Ronny]

From a person on another forum.

The interaction between the ground bounce return and the aircraft return creates several blind regions where the aircraft cannot be detected. The location of these regions can be calculated based on height and frequency. But this is not a common way to escape radar detection because these areas do not form a continuum in which the aircraft can inscribe its trajectory, they are rather small discontinuous regions between which the aircraft will be detected: the radar will see a dotted trajectory that a good filter will be able to reconstruct completely.

Basically, it seems that the blind spots are not as nice and continuous as they appear in that diagram.

The density depend on frequency though

 

[Forest Green]

The density depend on frequency though

Apparently it's not that simple though. You have ground height which is constantly changing and the gaps are very small and you also have some frequency modulation and shaping even with non-AESA radars. Plus the radar is scanning across and top-to-bottom, so the picture you provide is actually moving.

 

[Ronny]

The density depend on frequency though

Apparently it's not that simple though. You have ground height which is constantly changing and the gaps are very small and you also have some frequency modulation and shaping even with non-AESA radars.

I think only the height of the antenna and the height of the aircraft matter. Only signal reflected off the ground/sea surface close to the radar will interact with the target return signal. Besides, for sea based radar, the height won't change a lot in most case
The gap can be small for high frequency radar like X-band, but it is not small for L-band , UHF , VHF band

Plus the radar is scanning across and top-to-bottom, so the picture you provide is actually moving.

Only the radar lobe can move (where it steer its beam). The location of the null/lobe peak can't move

 

[Forest Green]

The density depend on frequency though

Apparently it's not that simple though. You have ground height which is constantly changing and the gaps are very small and you also have some frequency modulation and shaping even with non-AESA radars.

I think only the height of the antenna and the height of the aircraft matter. Only signal reflected off the ground/sea surface close to the radar will interact with the target return signal. Besides, for sea based radar, the height won't change a lot in most case
The gap can be small for high frequency radar like X-band, but it is not small for L-band , UHF , VHF band

Plus the radar is scanning across and top-to-bottom, so the picture you provide is actually moving.

Only the radar lobe can move (where it steer its beam). The location of the null/lobe peak can't move

You're making some rash assumptions about the sea right there. There's a reason carrier planes have stronger landing gear.

The transmitted frequency is changing though, as mentioned previously. The groundwave also depends on the type of ground. It's basically unpredictable, hence why nobody has exploited it. Theory vs practice.