losing lock very easily

[blast]

Hi guys,

 

Today I have another question about losing the radar lock in TWS and STT modes (aka PID and PIC).

 

For some reason, my radar unlock its target very oftenly, even if the target is in front of me at more or less the same altitude, and with no ground obstacle such as mountains between us. I also precise that it happened even when the target is not using ECM.

 

Which is VERY annoying since you have to select manually the target every time until the other guy finally took advantage of the situation. :joystick:

 

I also see that in close combat mode too.

 

Please, tell me it's a bug and it's going be corrected! If not, some advises would be appreciated.

 

Thanks for your answers.

[Azrayen]

blast, I share some of your concern.

 

There is a remaining bug with PID/TWS. This one is known, but fix doesn't seem easy.

 

About PIC/STT, perhaps the doppler filter needs tuning? I can't tell for sure, because I haven't had the time to fly dedicated tests missions.

Indeed so far, I saw radar unlock (or even contact lost on RWS) only when:

- target is beaming

- target relative speed is ~0

Both cases are logic, and intended. Now for the fine tuning part...

[gavagai]

I've experienced the same many times: The bandit is 10nm off my nose in STT, I fire the 530 and lose lock a few seconds later.:doh:

[tom1502]

Yep, this has just started happening for me again. I was doing the Standard Peg, or whatever it is called, mission in NTTR and the Su-27's get close, they're locked. I fire. Missile tracks, radar is pointing at the right elevation and suddenly, no lock, missile misses.

 

It doesn't discourage me from flying the Mirage, I love it, but it is annoying and it is meaning that I am not flying it online.

[gavagai]

I just saw this in the 1.5.3 change log:

 

Fixed radar lock lost bug

Fixed radar STT lock bug

 

So are we all flying on NTTR when we lose lock? Is it better on the Caucasus map?

[Blackjackk]

I am having this issue on 1.5.3 as well as NTTR. Its very unfortunate as it seems to occur most often after i have launched. I love the aircraft but this is a very frustrating issue.

[Azrayen]

So are we all flying on NTTR when we lose lock? Is it better on the Caucasus map?

No, I'm on Caucasus mostly.

But sure, if you use Nevada, it still hasn't got the update that fixes most of the issues related to lock.

 

Its very unfortunate as it seems to occur most often after i have launched.

And what is the bandit doing, then? Notching/beaming? Are you above or below him?

Are you familiar with doppler limitations?

 

Let's please (all) describe better what happens. As far as I saw it, it's never "random".

And again: if your target is beaming you, or if its relative speed is ~0, then a doppler radar will have problems.

How much remains to be seen, but unless you have a different scenario, it's theorically logic, and as such I see this as intended.

Edited June 13, 2016 by Azrayen

[blast]

blast, I share some of your concern.

 

There is a remaining bug with PID/TWS. This one is known, but fix doesn't seem easy.

 

About PIC/STT, perhaps the doppler filter needs tuning? I can't tell for sure, because I haven't had the time to fly dedicated tests missions.

Indeed so far, I saw radar unlock (or even contact lost on RWS) only when:

- target is beaming

- target relative speed is ~0

Both cases are logic, and intended. Now for the fine tuning part...

 

@Azrayen, thanks for your answer.

 

What do you mean by it happened "when target is beaming"? Does it mean when the target is locking me on its radar too (TWS/STT)? Or when the target is just scanning the area where i am (RWS)?

 

About the tuning, are you talking about the PRF settings? Mine is always set to high PRF (HFR). Is there another parameter? I noticed there was a gain button, do i have to tune this one?

 

I was wondering something: is it possible that i lose the lock because of target chaffs? For this, the target must know that i'm lock on him.

 

Is the targeted pilot aware when I lock him in TWS (PID) or just in STT (PIC) mode?

[Sarge55]

@Azrayen, thanks for your answer.

 

What do you mean by it happened "when target is beaming"? "Snip"

 

It means the enemy aircraft has put you on the "beam" of his aircraft, the 3-9 line. When they do this they are attempting to break lock by entering the "notch" in the tracking radar caused by ground clutter.

 

It seems it's working quite well.

[Blackjackk]

No, I'm on Caucasus mostly.

But sure, if you use Nevada, it still hasn't got the update that fixes most of the issues related to lock.

 

 

And what is the bandit doing, then? Notching/beaming? Are you above or below him?

Are you familiar with doppler limitations?

 

Let's please (all) describe better what happens. As far as I saw it, it's never "random".

And again: if your target is beaming you, or if its relative speed is ~0, then a doppler radar will have problems.

How much remains to be seen, but unless you have a different scenario, it's theorically logic, and as such I see this as intended.

 

I will perform tests after I get home from work and update you with my findings. It could possibly be user error as I have only been flying this bird for a short time. Either way I will keep you all updated.

[Azrayen]

About the tuning, are you talking about the PRF settings?

No I meant tuning the code of the aircraft = not something you or I can do, it has to be Razbam (if need be). This is part of the beta process ;)

[blast]

When they do this they are attempting to break lock by entering the "notch" in the tracking radar caused by ground clutter.

 

What is the notch? And what ground clutter have to do with it?

[Zeus67]

What is the notch? And what ground clutter have to do with it?

 

The most simple explanation is that doppler radar work by counting the doppler shift (the differences in wavelength) of the return signal. That way they know contact distance and closure rate. Also, the doppler shift allows the radar to disregard any contact that has a very low doppler value as ground clutter, this is called the doppler filter and in some radars it can be set by the pilot.

 

This has an unintended consequence, if an enemy pilot manages to put himself perpendicular, that is in a 90º angle, to the radar beam (not your aircraft) then his doppler shift gets down to 0 and for a brief moment the radar will break the lock and drop the contact since it assumes that it is ground clutter. This is called "notching" and it is a well known tactic.

 

The notching never lasts more than a couple of seconds, but it is enough to force a loss of lock and thus prevent interception.

 

Your only option is to maneuver in order to deny the notch to your target. If he achieves it, the radar will lose him for a little while. Long enough for any 530D launched at him to miss. This is not a bug, this is how doppler radars work in RL.

 

About Nevada, unfortunately all radar fixes has only been applied to 1.5.3 and not to 2.0.2. Not our decision but ED's. Hopefully 2.0 will get updated soon and you will get all the fixes that are waiting for Nevada.

 

Almost all the radar bugs have been solved, except for a couple that require ED's intervention since the problem is in the basic radar functionality.

Edited June 13, 2016 by Zeus67

[Azrayen]

Zeus, perhaps the notion of radar horizon could be implemented (if it's not already)?

 

Based on FC aircraft constatations (people, don't fret, FC modelization of air-air radar is quite evoluted):

- doppler filter is only activated when ground returns are detected

- this is calculated (for FC) by a tangent to the horizon: if all of your beam is above this tangent, then no doppler filter = no capability for the bandit to notch you.

- I don't think FC aircraft take the mountains into account. Perhaps this is doable for DCS modules? Would be even better.

[Zeus67]

Zeus, perhaps the notion of radar horizon could be implemented (if it's not already)?

 

Based on FC aircraft constatations (people, don't fret, FC modelization of air-air radar is quite evoluted):

- doppler filter is only activated when ground returns are detected

- this is calculated (for FC) by a tangent to the horizon: if all of your beam is above this tangent, then no doppler filter = no capability for the bandit to notch you.

- I don't think FC aircraft take the mountains into account. Perhaps this is doable for DCS modules? Would be even better.

 

I'll have to ask ED if it is possible for me to switch doppler filter off. Mind you that I've been told that FC3 radar implementation is far simpler than the one I am using as a base for the RDI.

[Azrayen]

Overall, probably simpler indeed; but I'm sure it manages that specific (& important) point :)

[jojo]

I don't remember to have lost the lock due to target beaming maneuver in look up scenario...

 

Did any anyone had this issue ? (loose lock on target above you)

 

Note:

Beaming and notching are the same thing:

Defensive maneuver to break a radar lock, by turning to put the threat radar to 3 or 9 o'clock position.

You have to go below the threat radar to make the maneuver effective, so it uses Doppler filters to eliminate ground return.

If you're flying perpendicularly to it's radar beam, your closing velocity is the same as the ground. So your aircraft radar echo is eliminated by Doppler filters with the ground returns.

 

"Beaming" is a word used to describe enemy maneuver.

"Notching" is a word used to describe friendly maneuver.

 

So while attacking a target, you can tell to your wingmen:

"Bandit beaming north" to describe a target trying to break your lock.

 

A wingman going defensive and trying to break enemy lock could tell you:

"2 notching south"

[Azrayen]

About PIC/STT, perhaps the doppler filter needs tuning? I can't tell for sure, because I haven't had the time to fly dedicated tests missions.

 

Nothing more for me as of now. :)

[blast]

I want to clarify something:

1. When i select a target in TWS mode, is the pilot aware that i'm locked on him? Or he's warned just when i lock him in STT mode?

 

2. About losing the target when im locked on it (TWS or STT), it happened for me every time in this situation: i fly very high like 40000 ft, the target is flying toward me in my 12 o'clock at a lower altitude such as 10000ft at a distance about 18 nm. I lock the the target in TWS mode only. Then i dive gently in order to move my nose in it's direction and i wait until my missile is in its range to fire (around 10nm). I lock the target in STT mode then. During this process i can lose randomly the lock. The radar change automatically the vertical tilt during all this process. And when i launched the missile, i lost the signal even if the target is in front of me .

I should make a video soon to show you.

 

3. Is it possible i lose the lock due to micro-lags in multiplayer (not talking about big lag)?

[Whisper]

I want to clarify something:

1. When i select a target in TWS mode, is the pilot aware that i'm locked on him? Or he's warned just when i lock him in STT mode?

 

2. About losing the target when im locked on it (TWS or STT), it happened for me every time in this situation: i fly very high like 40000 ft, the target is flying toward me in my 12 o'clock at a lower altitude such as 10000ft at a distance about 18 nm. I lock the the target in TWS mode only. Then i dive gently in order to move my nose in it's direction and i wait until my missile is in its range to fire (around 10nm). I lock the target in STT mode then. During this process i can lose randomly the lock. The radar change automatically the vertical tilt during all this process. And when i launched the missile, i lost the signal even if the target is in front of me .

I should make a video soon to show you.

 

3. Is it possible i lose the lock due to micro-lags in multiplayer (not talking about big lag)?

 

1. Afaik lock warning will happen only when going in PIC. that's for human targets. No clue of the amount of cheating the AI has access to :)

2. Monitor your target direction changes during your approach, does it go perpendicular to you? If so, your target is beaming, as explained above, and is trying to have a speed relative to you equal of the speed of ground relative to you, so that your radar filters out the echo and breaks lock. I usually change the PRF setting in this case to ENT (not BFR!) To keep PID lock. It seems to work well, as long as target is not too far away. If below target,keep PRF to HFR.

[Azrayen]

I should make a video soon to show you.

You should :)

Or a track.

[blast]

1. Afaik lock warning will happen only when going in PIC. that's for human targets. No clue of the amount of cheating the AI has access to :)

2. Monitor your target direction changes during your approach, does it go perpendicular to you? If so, your target is beaming, as explained above, and is trying to have a speed relative to you equal of the speed of ground relative to you, so that your radar filters out the echo and breaks lock. I usually change the PRF setting in this case to ENT (not BFR!) To keep PID lock. It seems to work well, as long as target is not too far away. If below target,keep PRF to HFR.

 

Thanks for the answer.

 

I will try to switch PRF to ENT next time. I used to stay on HFR all time. About this point, the manual mention that PRF set to ENT is not able to follow the target in STT but only in TWS. I assume you switch to HFR before launching the missile?

[nomdeplume]

I will try to switch PRF to ENT next time. I used to stay on HFR all time. About this point, the manual mention that PRF set to ENT is not able to follow the target in STT but only in TWS. I assume you switch to HFR before launching the missile?

Yes. Currently you have to do it manually, in a future update the radar will automatically switch to HFR if needed and try to transition to PIC/STT mode if it can. It does take slightly longer to fire the missile then, but only 1.0 second vs 0.8 seconds (currently missile launch is instant, but that will change, too).

[droopy114]

Yes. Currently you have to do it manually, in a future update the radar will automatically switch to HFR if needed and try to transition to PIC/STT mode if it can. It does take slightly longer to fire the missile then, but only 1.0 second vs 0.8 seconds (currently missile launch is instant, but that will change, too).

 

Interesting, never think about this. Thanks for the tip, I will give it a try to.

[gavagai]

The manual says you need STT for weapons guidance. What is to prevent the target from breaking lock again after you switch to HFR to launch the 530?