Need explanations about N-001 Phazotron ?

[Majesco]

I've read the LockOn manual but i do not understand this passge (can't imagine)

 

Su-27 BVR - Scan mode:

"The expected target aspect hemisphere is controlled with the [Win-I] key. АВТ (ILV) mode can be used if the target aspect is unknown. The expected target aspect determines the pulse repetition frequency (PRF) to be used by the fighter radar in search mode. High PRF (HPRF), which provides the longest detection range against approaching forward-hemisphere targets, is indicated by ППС (HI), whereas medium PRF (MPRF) for receding rear-hemisphere targets is indicated by ЗПС (MED). In АВТ (ILV) mode, high and medium PRFs are interleaved on alternate bars of the radar scan pattern. This provides all-aspect target detection at the expense of a 25% reduction in maximum range"

 

What's "the expected target aspect hemisphere" or "expected target range" ?

ILV = Interleave mode ?

I don't understand these 2 phrases "against approaching forward-hemisphere targets" and "receding rear-hemisphere targets". Could anybody explain me this problem by drawing a diagram or smth like that ?

 

Thx

Edited June 10, 2008 by Majesco

[GGTharos]

approaching forward-hemisphere targets

You're head to head with your bandit.

receding rear-hemisphere targets

You're looking at your target's tailpipe, and what's more, he's actually getting away.

And yes, ILV=Interleave (they do part HI, part MED PRF, switched automatically)

[Majesco]

Thank you, GGTharos

 

so, what about the "expected target range (expected target aspect hemisphere)" ?

can you explain more ?

is maximum expected target range just 150km only ?

 

/ my Eng is not good

[GGTharos]

Expected range is a parameter you feed into the radar to control elevation.

As you know, you can command elevation of the radar at 1km increments relative to your altitude.

 

If you set expected range at 10km, the angle required to cover 1km up/down is MUCH larger than it is at 100km.

 

It's not terribly useful in LO because the radars always use 4 bars to scan (meaning the scan plenty of altitude ... the rule of thumb for LO radars is, at least with the F-15, you'll scan 1000' of altitude per nm of range ... ie. your vertical scan space at 20nm is 20000' ... assuming I recall this correctly.)

 

For Russian birds, I think you'd be looking at something around 1.7km altitude per 10km distance.

 

Don't take my word for this, my math might be off here ...

Edited June 10, 2008 by GGTharos

[RedTiger]

GG is right. A give-away about what this does (and I figured out what it did) is the reading at the left of the HUD. Notice how at 10km expected range one notch up makes the bar jump up much farther than say, 100km. The place I find this to be crucial is between 50km and 20km, the edge of BVR and WVR. I was surprised how much easier I could reaquire a bandit after understanding how to make use of the expected range.

[Boberro]

Hmmm maybe I will use it, but is there any method to set it always on example 30 km? When I "exit" from BVR mode it resets to 10 and again I have to set 30 km :)

[RedTiger]

I don't think so. The best thing to do is put it on your HOTAS or Joystick. I have that function as well as the keys for increasing and decreasing radar range mapped on a 4-way hat on my throttle. I'd be willing to bet that its the single most under-used and under-appreciated function those radars have. Its all just extra workload the pilot shouldn't have to do, but if you wanna use the radar right, you have to. :)

 

While I'm at it, I have a question. Can anyone confirm that you will burn through the bandit's jamming sooner if you use the proper PRF setting? It seems that way to me. If I turn towards the bandit, using the SPO, and switch to Hi PRF, I swear that I burn through sooner than I would using Ilv or Med.

Edited June 10, 2008 by RedTiger

[S77th-konkussion]

It's quite simple, actually.

[monotwix]

It's quite simple, actually.

Worth trying...

Can it fire through a canopy though?