reported Radar look down problem - Low flying, fighter size targets not detected from high altitude

[maxTRX]

2 Su33's head on, level at 1500 ft.

I'm at 40k feet, Hi PRF then INTL.  Unable to pick them up.

 

 

[Tholozor]

Have you tried just using MED instead of INTL when they get closer?

[maxTRX]

2 hours ago, Tholozor said:

Have you tried just using MED instead of INTL when they get closer?

 

It didn't make any difference from 42k ft.  It's weird.  I tried to paint the same targets from 35k ft., using mixed PRF and I picked them up at 35 nm. From 25k, the targets show up at 41 nm.

[SharpeXB]

I’ve noticed that I can’t pick up bandits down on the deck, over water, even high aspect, no matter the PRF. And it’s a good position for them because they can sure lock me up. 

[GGTharos]

Put this in the bug section along with a track.  The radar doesn't care one bit what your altitude is as long as there's enough closure.  Range might be reduced but flying low doesn't confer stealth.

Edited August 23, 2021 by GGTharos

[maxTRX]

I'll try to get to the flightline tonight and make a simple track, unless someone beats me to it. The one from the vid above is from a 'convoluted' huge mission with loads of jets.

 

[maxTRX]

I just flew a simple setup:  1 Su33 @1500 ft. hot  and  1 Tu160 @ 500 ft. hot,  separated by a few miles, line abreast.   I was between 42k and 43k.

I picked up Tu160 at 38nm, never picked up Su33.

At some point I 'conveniently' lost link with AWACS when E3 turned away from me... he was supposed to be in orbit @44k ft.  I wouldn't have made any difference as you can see in my vid in the op. I regained the link when the Su33 was at around 8nm on the nose... well, below the nose and I wasn't able to re-acquire.

I'm posting a track in the bugs section.

[maxTRX]

I started the above thread in Hornet's main forum.

 

When flying level at 42,000 ft. I was not able to detect low flying fighter size targets (Su33's). The bombers like Tu160 showed up fine.

 

Look down.trk

Edited August 23, 2021 by Gripes323

[SharpeXB]

Here's another track, rather long from MP but you can see the attempt to lock the bandit at the end

https://www.dropbox.com/s/9x5ss8ev0hnlvza/BF Syria Modern 1.31.miz-dynamic-20210823-124316.zip?dl=0

Stable version 2.7.5.10869

Edited August 24, 2021 by SharpeXB

[BIGNEWY]

Hello both,

 

this is correct as is, When a pulse Doppler radar detects a target below its horizon, it should have a reduction in detection range due to look-down clutter.

 

Thank you

[jackdaw]

Whats the point of having a look down radar if it does not work!

[BIGNEWY]

RADAR is not a all seeing magic device, it has limitations. 

[jackdaw]

45 minutes ago, BIGNEWY said:

RADAR is not a all seeing magic device, it has limitations. 

Keep the sarcasm to yourself, so at what slant range would you expect to detect a fighter sized object whilst looking down

Edited August 24, 2021 by jackdaw

[falcon_120]

Bignewy, its different if we are talking about a reduction in range versus talking about inability to detect at all. Haven't tested myself so I can't confirm.

 

@Jackdraw no need to be rude, i don't think there was any sarcasm in the response.

 

 

[BIGNEWY]

10 minutes ago, jackdaw said:

Keep the sarcasm to yourself, so at what slant range would you expect to detect a fighter sized object whilst looking down

 

 

There was no sarcasm so please calm down. 

I will speak to the team about it. 

 

thanks

[SharpeXB]

In my case the target was very close and still remained undetected. 

[Kapsu]

Did some testing and found out that when look down angle is higher than 14-15 degrees radar won't see anything in RWS/TWS. That combined with look down detection range reduction scaling based on altitude difference or angle means that from 40k feet it won't detect low flying fighter sized target before the look down angle gets higher than that 14-15 degrees so you won't ever detect the contact in that scenario.

[Harker]

@BIGNEWYLook down detection should not be an issue for the APG-73, unless the target is flying in the weeds and mixed with the ground clutter. And even like that, it shouldn't be impossible to detect, just have a decreased detection range. The detection performance shouldn't decrease if we're talking about a target at 15,000 ft, while I'm at 25,000 ft. It's a Doppler radar, it should be able to pick up a contact like that, because the Doppler return from the target and the return from the ground are completely different.

 

Same should go for missile seekers, BTW.

 

If you want to confuse a radar like that, you need to be in the weeds and mixed with the ground clutter, not just be below them. Especially for missiles, consider
that they often come down at targets from above, due to lofting.

Edited August 24, 2021 by Harker

[SharpeXB]

The target I was looking at was high aspect, not notching, over the water so not hidden by terrain, right on the deck and pretty close. Almost like the player knew it would be an exploit. 

[BIGNEWY]

Ive spent time testing it today and it seems to be working as intended,  ( degrades range based on angle. It only reduces range by 0.035 for everyone 1 degree down )

 

I have tested with Tu160 and Mig-29 and have been able to find and lock targets. 

[Wizard_03]

So for 15 degrees down the normal detection range is roughly cut in half. On top of RCS checks, aspect, scan volume, ect. 

 

Gonna have a hard time in that scenario.

 

[Svend_Dellepude]

Here are a few tracks of me headon with an AI F-18 at 500knots GS. Two in a lookdown and one in a lookup situation.

I the lookup there are of course no problems detecting the F-18, but in both lookdown situations the track is lost somewhere between 10-20 NM, and the headon F-18 is never detected in MPRF mode.

 

Lookup 10k-40k over water.trk Lookdown 40k-20k over water.trk Lookdown 40k-10k over water.trk

Edited August 24, 2021 by Svend_Dellepude

[Kapsu]

20 hours ago, BIGNEWY said:

Ive spent time testing it today and it seems to be working as intended,  ( degrades range based on angle. It only reduces range by 0.035 for everyone 1 degree down )

 

I have tested with Tu160 and Mig-29 and have been able to find and lock targets. 

Real problem here isn't look down range reduction. Real problem is that after certain look down angle (around 15 degrees) radar won't see or track anything in RWS or TWS even if you had solid track on the contact, after that angle radar will just loose the contact without reason. 

[Andrei]

If the track is completely lost in look-down situation with reasonable closing velocity, this is a different issue, and I don't think this is 'correct as-is'

[Svend_Dellepude]

In my tracks Vc was just below 1000 knots when the track was lost.