Finding the needle in the haystack

Radar needs to constantly evolve to address new challenges that arise. Here, we take a look at how modern radar deals with three tricky problems: stealth, birds, and jammed environments.

When radar was first introduced during the Second World War, it typically looked at the middle range. That evolved to a detection range that fit the time needed to reach the target, whether that was fighter jets or guiding missiles.

Further development led to radar becoming smaller while covering larger areas. This was very successful until opponents began creating problems, one of which was stealth.


Stealth doesn’t mean invisibility
“A lot people believe stealth means invisible,” says Anders Linder, head of Surface Radar Solutions at Saab. “But there is only one invisible product in the world: Harry Potter’s invisibility cloak.”

Stealth is actually the ability to become smaller in the eyes of radar, so that it will look different from different angles.

“Take a missile that is seven meters wide and one meter in dimension,” says Anders Linder.  “That is a big missile by any measure, but if you look at it from different angles, it has different sizes.

If we look at the missile from one angle, it’s the size of a basketball. From another, tougher angle, it’s the size of a baseball. And from the toughest angle, this huge missile is the size of a golf ball.  Now, imagine trying to find a golf ball travelling at a high speed for a long distance. It’s not easy.

“The detection range of existing radar is much shorter than the distance needed for interception,” explains Anders Linder. “And the arms race of today is a battle between stealthier targets and increasingly advanced radar.”

 

The bird issue
Another problem is the clutter caused by birds. Drones, or unmanned aerial vehicles (UAVs), are small and they fly low and slow. Birds have these same characteristics, and it can be difficult to parse out the real threats from the animals.

Imagine a radar operator seeing 100 targets on the screen and 99 of them are birds. That’s a lot of clutter. Increasing the ‘brains’ of the radar allows it to separate out birds and the operator no longer sees them.

 

Dealing with jamming
A third problem is jamming.  If you have good radar, opponents will try to jam it by throwing a lot of energy and microwaves against it. In order to detect the target, the radar needs to be sharp enough to send a very thin, powerful signal through the middle of the jamming. This is comparable to trying to hear a bumblebee while standing on a runway while a plane takes off. It sounds impossible, but it’s the equivalent of what modern radar is capable of doing.

Anders Linder says, “Modern radar is capable of addressing three big problems: stealth, birds, and a jammed environment – and it will continue to evolve as opponents and other factors create new problems.”