Doppler notch and altitude

[Twitch]

Hello , I'm fairly new at FC and I just recently started to train for F-15 (I flew A-10 before).

I'm trying to learn the A to A combat basics and I have a question about doppler notch maneuver.

 

As I understand you have to be in a look-down position to your opponent (which means that you are below his horizon line) in order to be masked by return signals from ground. You also have to fly perpendicular to him in order to stop doppler shift from your return signals giving you away.

 

My question is: In addition to the above parameters, do you have to be below some certain altitude for notching to work?

 

As I understand radar is like "high speed sonar", it sends a pulse and measure the time it takes to get a return signal to calculate distance to target, it also records the direction of the return signal and its altitude by cross referencing it with his own altitude. Can the radar software take the altitude of a return signal and go: "gee that point is at 10 000 km altitude, so even though it doesn't give doppler shift, I'm sure it is a plane since it is higher than the highest point on earth!"

 

I realize that the plane sends radar pulses in rapid succession and distance information is lost in the porridge of return signals arriving several pulses after from distant points from ground, but surely their signal strenght of those return signals is so weak that they can be rejected? Expecially at high altitude engagements...

 

Thanks in advance,

[Jay]

Hi Twitch,

 

you're right that the target's altitude has certain impact on radar effectivenes and its tracking capabilities. But newer radars with advanced hardware supported with newer software are more succesfull in this than older ones.

 

You can find some interesting information and comparison of american and russian radars' capabilities on pages 113-116 in the Lomac manual. There you'll also find answer to your question regarding radar's abilities to separate signals reflected from the target and those from the ground.

 

Good hunting!