Radar Elevation Antenna

[Biga42]

I've watched the Growling sidewinder's and RedKite's videos regarding how the radar works and I believe that i'm familiarized in how to lock targets in the radar. But seems that the TDC cursor altitude numbers are not corresponding correct with the increasing or decreasing of the antenna elevation.

[Moafuleum]

And why?

[Biga42]

Because it's harder to lock targets than should be. Any small movement in the antenna up or down, changes a lot the scanning altitude.

[Kang]

Well, what range are you putting the TDC at? A small change in antenna elevation adds up to a large change in scanned altitudes when you're 60 miles away.

[KittyVCAW-1]

Because it's harder to lock targets than should be. Any small movement in the antenna up or down, changes a lot the scanning altitude.

 

The f-18 has that control on a wheel so you can move a little or move a lot. Is yours set up on an axis? Then tune the curve out of the axis and you can move it really slow after you make those changes.

[Svend_Dellepude]

I remember reading somewhere that: The elevation should bump the elevation 1000ft up or down at the cursor position for each press. I dont remember where i read it though, but that is not how it behaves ATM.

[noisy_lightning]

What is your ban scan set to? If its a single bar then it will make huge changes, a higher bar setting will give a wider acquisition block of altitude.

 

I tend to use 4 bar for finding targets then when I have it narrowed in drop it to 2 or 1 bar when I want a higher refresh rate on a contact.

 

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[Fri13]

I remember reading somewhere that: The elevation should bump the elevation 1000ft up or down at the cursor position for each press. I dont remember where i read it though, but that is not how it behaves ATM.

 

Are you use you are not remembering the Su-27S (MiG's etc) radar function where the elevation set (like +1, +2, +5 etc) affects to the range of the radar gate? So if you move the radar gate further and set at +2, then you are scanning 2km upwards from that range, and if you move gate closer and still have it +2, then you are still scanning 2km upward from that position.

 

So alone setting radar scan elevation by 1km and moving radar gate further and closer will tilt the radar more or less, and so on you can scan something further and higher.

[Svend_Dellepude]

Are you use you are not remembering the Su-27S (MiG's etc) radar function where the elevation set (like +1, +2, +5 etc) affects to the range of the radar gate? So if you move the radar gate further and set at +2, then you are scanning 2km upwards from that range, and if you move gate closer and still have it +2, then you are still scanning 2km upward from that position.

 

Yes im sure it was for the Hornet, if only i could remember where i read it.

 

 

So alone setting radar scan elevation by 1km and moving radar gate further and closer will tilt the radar more or less, and so on you can scan something further and higher.

 

From my understanding you just had finer control of the elevation even at long distance, but not working like the russian radars where the elevation changes as you increase or decrease the range gate.

The angle would be the angle.

[Biga42]

as you can see in the picture the TDC is at the exact point the AWACS told me the enemies are, the altitude the radar is scanning is between -38 + 32 and the only aircraft spotted is the AWACS.

[probad]

detection varies with aspect, you are trying to look for cold targets at 80nm...

[Fri13]

detection varies with aspect, you are trying to look for cold targets at 80nm...

 

There is a bug in the hornet radar at this moment.

The radar doesn't find anything regardless their aspect, range or altitude being optimal

 

Until you do something like switch to gun and then back to missile and then you suddenly find all the targets again until you lock something and need to switch again to gun first.

[DeathAngel1]

I noticed that also. Last time I was flying vs two MiGs at range of 60-70 nm, 15000 feet, exactly against them, and I was locked by MiGs and after that I was shoot down, my radar was totally blind to the end.

[Biga42]

detection varies with aspect, you are trying to look for cold targets at 80nm...

 

please elaborate..

[Wizard_03]

please elaborate..

 

The radar uses the Doppler effect. If the target is moving away from you or perpendicular to your radar LOS it makes a huge difference in how detectable it is.

 

So you need to set the right PRF setting, in the screenshot you’ve got it in INTL which cycles medium and high. That setting is used when you don’t know the targets aspect, and will limit the radars ability to detect targets at different aspects. Set HI for hot targets and MED for cold ones. Use INTL when the target is beaming or its aspect is unknown.

[DeltaMike]

Jabber's video on the F14's radar is really interesting, because in that a/c you can you can look at the raw pulse doppler data and see how it behaves. Gives you an idea of what's going on under the hood, never really understood pulse doppler blind spots till I saw that demo. It's worth a watch.

 

Bottom line is, a pulse doppler gives a return based on relative speed. If the bad guy is coming at you fast, say with 1200kts closure, you'll get a really strong signal. If he's going the other way, you either need to be going way faster than him (eg closure rate 300kts) or way slower (eg closure of negative 200kts) to get any signal at all. If you think about it, that's not going to happen all that often if one fighter is chasing another.

 

In your example, if the bad guy was screaming toward you at 600kts, you probably would get a signal from 80 miles out, although it might be hard to lock him up.

 

Doppler also filters things that are coming at you, at the same speed you're coming at them. Say you're flying 1200kts. Anything that appears to have a closure rate of 1200kts is filtered out, because the computer assumes that's stationary, it's not flying. Like a mountain.

 

That's not always true, of course. If the dude is flanking you, he might be going 600kts, but not in your direction, or particularly in the opposite direction. So (under some circumstances) that'll get filtered out. That's the so-called "notch" filter and why those pesky Sukhoi's will like to "notch" you, ie put you on your wing, and disappear off your radar.

 

In that case you'd rather have an old-fashioned radar that gives you range information without all the fancy doppler stuff, right? Except then you get blinded by ground clutter and rain and stuff.

 

Medium PRF pulse doppler (near as I can tell) is sort of a compromise, it has the advantages of doppler but gives you some halfway decent ranging ability, making it hard for somebody to notch you especially if you are below them, looking up. Or, if they are fairly close and moving away from you. Basically trying to fill in the gaps of high-PRF doppler, imperfect though it may be.

[Biga42]

Thanks man, I got the point!

[Svend_Dellepude]

 

Bottom line is, a pulse doppler gives a return based on relative speed. If the bad guy is coming at you fast, say with 1200kts closure, you'll get a really strong signal. If he's going the other way, you either need to be going way faster than him (eg closure rate 300kts) or way slower (eg closure of negative 200kts) to get any signal at all. If you think about it, that's not going to happen all that often if one fighter is chasing another.

 

Not only that, but rf pitch will increase with positive closure, and decrease with negative closure. If stationary, or perpendicular, pitch stays the same. That is what doppler is all about.