What's going on with Hornet's radar?

[Hulkbust44]

Whatever the reason is... balancing or unbalancing sounds like a possibility.  Now, Andrei brought up the sidelobes...  I don't think so.  When I have time I'll make a detailed test following some books on the subject. There's a thick layer of dust that has collected on them and that is the reason why I'm hesitant to elaborate on the subject at the moment, until I look it up. 
'Beamscanner' could probably answer this in one quick post... if he stumbles on this thread.

Absolutely, hailing the Calvary

@Beamscanner

[Schmidtfire]

It's not about balancing, it's about available time and priority to get it right. Usually there is some sort of synergy in the development cycle.
For example Super Carrier updates will most likely yield Hornet updates. So when ED turns back into navy stuff again and advertise the big Super Carrier
features we will likely see more progression on the Hornet (as a Hornet in good shape will sell more Super Carrier DLC's). Common sense really.

[dundun92]

I dont know why we are mentioning balance when the F-16 is affected by this exact same functionality (both low alt detection range and lookdown detection range reduction), and in general the F-16 radar is by far worse than the F-18s rn in both detection range and tracking reliability (combine it with stuff like the F-16 DL ghost contact bug, etc). The low altitude detection ranges for the F-16 are abysmal. Whether this is fully realistic, I dont know, but at least IMO it probably shouldnt; sidelobe clutter wont be in the frequency spectrum of a hot target; its one of the reasons HPRF sees hot targets so far away; they are in a "clutter free" part of the spectrum. But I'm not an RF expert, so maybe I'm wrong here.

Edited April 13, 2022 by dundun92

[Beamscanner]

What should happen:

• Sidelobes increase as you lower your altitude.
• Sidelobes increase as you tilt your antenna downward. 
• Sidelobes should decrease as you tilt your antenna upward.
• Sidelobes can effect both MPRF and HPRF in different ways.

MPRF processes range and doppler, though these parameters are highly ambiguous when initially collected. MPRF has to cycle through a number of PRFs in order to resolve these ambiguities. That being said, MPRF will having sidelobe energy overlap targets in both range and doppler. Thus you should see reduced detection range at lower altitude, though I think low alt+look-up should have better range than high alt+look-down.

 

HPRF should only be effected if the target is within the sidelobe clutter region. If the target is within the clutter free doppler region, the radar should experience little to zero performance loss. 

 

I think the problem is that ED is not simulating the above. I think ED is just applying blanket rules. (ie reduce range by X% if altitude is below Y) 

 

For the OP's incident, the sidelobe shouldn't of done much to hinder him. A high speed head to head closure would've likely put the target within the clutter free region of the doppler spectrum. And thus the sidelobes, while stronger due to low flight, don't even exist in that band of the frequency spectrum. 

 

Blanket rules like this wont work if you only use ownship position. I would say that they should include antenna tilt, target closure, and PRF selection in this calculation (with the possibility of zero performance loss in certain closure speeds in HPRF). 

 

But I think the best solution is the one Razbam and Heatblur have taken. Simulate radar detection. That way no blanket rules are used in places they shouldn't be.

[HILOK]

@Beamscanner thanks! what's the vertical axis in the graphs, the degree of clutter?

[Beamscanner]

11 hours ago, HILOK said:

@Beamscanner thanks! what's the vertical axis in the graphs, the degree of clutter?

Amplitude. 

 

The graph is Amplitude over Radio Frequency. ("doppler spectrum" is just frequency, but more specifically the narrow band of frequency around the carrier frequency)

 

A target could appear anywhere in the plot. But the clutter is somewhat predictable, hence the generic plot. 

[oldcrusty]

Well, it does seem like some sort of side lobes noise is simulated.  What is probably not entirely simulated how Hornet's radar deals with it. I wish I knew... 

I did some testing and it looks like in the current OB, we can see a gradual decrease in detection range, starting at around 5000 ft. above ground (my tests were done over water). I also tested at 4k, 3k, 2k, and 1k ft., intercepting the same target (F15E), hot aspect, flying at different altitudes. Using HPRF or 4bar/60deg INTL PRFs made no difference for these aspects.

With target at 33k ft. hot, I could detect him at 43nm, from ownship altitude of 10k, 6k,  and down to 5k ft., looking up.

From 4k ft. looking up at the same target at 33k, I could pick him up at 35nm.

From 3k ft. ~  at 29nm.

From 2k ft. -  at 22nm.

From 1k ft. ~  at 15nm.    

Surprisingly, when coaltitude, hot at 200 ft. ,  I could see him at 18nm.

 

Look down detection ranges at altitudes within the side lobes noise (5k ft. and down) were not surprising. Similarly from high altitudes. Just one example:  From 33k ft. looking down at same target, hot at 200 ft. ~ detected at 31nm.

Coaltitude, hot at 33k ft.  ~  at 46 nm.

[MARLAN_]

Lately I've been noticing radar look-down has been absolutely atrocious since the past patch or two. If a bandit is even a few thousand feet below you they're invisible. Whether over water or land it doesn't matter.

[BIGNEWY]

The team have adjusted the look down penalty and it will include side lobe modelling, this will be in a future patch. 

thanks

[MARLAN_]

17 minutes ago, BIGNEWY said:

The team have adjusted the look down penalty and it will include side lobe modelling, this will be in a future patch. 

thanks

Just saw the post from Wags, this is great to hear, really excited for the next patch! Thanks for all the hard work.

[Kang]

3 hours ago, BIGNEWY said:

The team have adjusted the look down penalty and it will include side lobe modelling, this will be in a future patch. 

thanks

Does this imply that the current state is indeed a bit work-in-progress and might have introduced a few problems that are bound to be fixed, or is the current state a step closer to what it is supposed to be?

[Tango3B]

On 4/13/2022 at 9:31 AM, Andrei said:

From what I've heard the reduced detection performance of the radar when flying at low level looking UP is intentional. Reason: significant side lobe noise.

Hey, Andrei. I know you were only forwarding the message that you have heard from the official side but the point is that the factor which reduces the detection performance is currently way too big. Modern A/A radars do all have certain means of reducing unwanted clutter and/or noise by very capable digital data processing in a way that it barely impacts your detection range. This applies not only to look-up scenarios but also to look-down scenarios. And please do not get me wrong here, I do not argue that there are "some" negative effects on the ability to detect a target under these conditions but in no way in this world was a hard-coded reduction of your ability to detect a target with an APG-73 (or an APG-68v5) in a look-up scneario ok which only yields you a detection range of barely above 15nm. This is simply not justifiable and much too drastic as we do not fly a MiG-23 with some kind of ancient analog signal processors here. It is very nice to see that ED is already aware and will adress this problem in a future patch. Let´s see how this turns out, then.

 

Edited April 16, 2022 by Tango3B

[StarLiner]

On 4/16/2022 at 9:09 AM, BIGNEWY said:

The team have adjusted the look down penalty and it will include side lobe modelling, this will be in a future patch. 

thanks

This is awesome, thank you! Is there any chance future modelling could impact the Hornet's vulnerability to notching when in look down? Both the Tomcat and Mirage's radar modelling has things that realistically deal with a notching target, while the Hornet seems to just completely give up.