reported A-G radar EXP3 and aircraft movement issues

[Rissala]

A-G radar accuracy.trk

When wags introduced the EXP modes, he said that "you can put a weapon on" the designations. This is currently impossible. I tried hitting an AN-26 (medium transport plane) with the last designation happening at 9 nm with EXP3. The JDAM missed about 100 meters. This was literally a best case scenario since going any closer would slow down the scan rate of the radar too much and other alternatives would be a better choice. (unless bad weather like in the scenario)

 

I have never successfully killed a ground target with the A-G radar designation and a JDAM in multiplayer or singleplayer.

If the radar is supposed to be used for weapon designations (like in wags video for example) , I would assume it should have like a 25 meter accuracy radius. Currently it is extremely unlikely to hit literally anything.

Edited November 17, 2021 by Rissala

[deathbysybian]

Put a t-pod on to see where you're actually designating. 

I have a suspicion it's only accurate the moment it's drawn.  Since it can take several seconds to update the image it can be very far off.

[Hammer1-1]

Id like to think the radar is tied to the GPS and moving map display somehow in DCS but I doubt this is the case. If they were both the same thing, then yeah it would be accurate...but I suspect they arent tied to each other in any way. What I mean is that the radar is basically just drawing the map and not actually rendering its own image per se, but its a separate image that isnt tied directly to one another. To make it sound stupidly simple (and Im not saying it is, just hoping it is but I dont think it is) the GPS moving map and the radar are the one and the same, just rendered differently. If it sounds like Im talking out of my ass, then yeah. I think they are both 2 differently drawn maps, and they dont mesh together.  Hopefully someone understands what Im talking about though...

Edited June 14, 2021 by Hammer1-1

[Santi871]

The radar is not that capable. Not a bug.

Edited June 15, 2021 by Santi871

[Hammer1-1]

1 minute ago, Santi871 said:

The radar is not that capable. Not a bug.

 

If its advertised that it can, theres the problem.

[Spectre1-1]

advertised where exactly ?
the fact that it can designate doesn't mean it can do it accurately
see: nitehawks not being allowed to self lase despite being advertised with the capability

[deathbysybian]

What's the purpose of marking targets in the a2g radar? 

What's the point of Wags tutorial on how to use it to attack ground targets?

Edited June 15, 2021 by deathbysybian

[Hammer1-1]

3 hours ago, Spectre1-1 said:

see: nitehawks not being allowed to self lase despite being advertised with the capability

If its advertised you can launch off of a designated radar point, then thats what it should be able to do. The only weapons available to do just this would be JDAMs, and if its not accurate then it defeats the purpose.  Also, the nitehawk reference is kind of a bad analogy; you could theoretically spot the laser thus giving away the aircrafts location. Different points of logic.

[Fri13]

1 hour ago, deathbysybian said:

What's the purpose of marking targets in the a2g radar? 

What's the point of Wags tutorial on how to use it to attack ground targets?

The A-G radar is not used in reality same way as in Wags video because it is so bad.

 

It is good when you need to find a large ship at sea, or you have very definitive ground echo like train station, harbor or big city.

Why the A-G radar is used in sea mode. But you don't find stealthy ships at long range or smaller boats even at close. Why navy has been not so effective against drug traffickers who are using high speed small boats. You need better, larger radars to that. Why helicopters can carry massive radars or you simply call E-2 Hawkeye for business.

 

You can find those first on map, then Designate on radar for general area. 50 m accuracy is pretty amazing for it. Remember that you are dropping a 250-500kg bombs that has effective radius of that level against lightly armored vehicles and non-armored vehicles all the way to 100-300 meters. It is limitation in DCS that fragmentation is not simulated, why you need to be almost pinpoint accurate with bombs.

 

The Litening or ATFLIR shouldn't be great for GPS coordinates generation, but you are very accurate with laser. This is reason why JDAM is used (as few pilots said) mainly via pre-designated coordinates on the ground. You just fly the JSOW or JDAM on optimal release position and get out.

 

Navy ECM operations are as well about quickly getting in and out, this you can hear from fighter pilot Podcast about wild weasels. So they just spend could minutes in the danger area and then bug out. You don't have time to search and designate targets there, why you want to have all ready when you enter the area and you just need to designate weapons in Waypoints and release.

 

Why you are flying with A-G radar, you need to understand what you can get with it. On a flat desert you can find a compound, but it is on map as well. You can designate about main directions in that compound, but not individual buildings as you don't have time. 

 

In a reality your A-G radar doesn't pick up moving vehicles either than on highway or other paved road. Off-road, camouflaged, anti-IR and anti-radar methods renders vehicles invisible to radars and FLIR so effectively that you don't spot them as now in DCS. Why you need to be looking FLIR as black and white TV to what you are seeing and interpret it. So you wouldn't be looking "big white blobs" but old school TV.

 

And your radar would be just useless as it can't detect vehicles as they don't reflect any radar signal in sensible manner.

 

DCS doesn't simulate any of that, why you have so easy time to find moving vehicles and spot them with FLIR.

 

 

 

 

[Fri13]

4 hours ago, Spectre1-1 said:

see: nitehawks not being allowed to self lase despite being advertised with the capability

 

The Nitehawk pod is sad story for DCS. In 2005 it would be the main targeting pod for our USN C model hornet (Only Marines D hornets and Navy Super Hornets used ATFLIR and LITENING, the C hornets had only Nitehawk in use) as only 1-2 ATFLIR and LITENING were in testing purposes for future decision that what USN/USMC and Spain will purchase. Why it is more fictional that we have ATFLIR and LITENING when we should have only Nitehawk, as only after 2005 those were purchased and taken in service (suggestion for ED, keep ATFLIR and LITENING for Hornet, but develop Nitehawk and make it primary sensor pod).

 

The Nitehawk requires two pods if wanted to self-designate. You have laser designator and then another pod with LST/CAM to generate the target coordinates for your own system or just as wingman to carry that another pod. This is why ATFLIR or LITENING were so big deal as they left one attachment point free for weapons by having all in one pod.

 

And as you say, Nitehawk was not allowed to be used for self-designation because it was so low quality video and FLIR that pilot couldn't see is he targeting friendlies or enemies. So too many "blue on blue" accidents and hence LST pod was only allowed to be used for ground designated targets.

 

We are getting the new FLIR modeling, that hopefully adds proper low resolutions to all optical systems and renders them a lot worse than they are now.

So welcome the 320x240 (LANTIRN and Nitehawk) and 640x512 FLIR as ATFLIR and LITENING AT and finally DCS best targeting pod, AV-8B only Litening G4 with 1024 x 1024 FLIR and CCD (with laser scanning imaging process).

 

 

[Fri13]

1 hour ago, Hammer1-1 said:

If its advertised you can launch off of a designated radar point, then thats what it should be able to do. The only weapons available to do just this would be JDAMs, and if its not accurate then it defeats the purpose.  Also, the nitehawk reference is kind of a bad analogy; you could theoretically spot the laser thus giving away the aircrafts location. Different points of logic.

 

Yes you could spot the laser source if you point laser at the detector. But again it is not enough. It is not a IR laser for NVG use like you can do for pointing. The Harrier Litening G4 supports dual-mode laser, where you fire laser designator and IR laser same time so you can guide laser weapon and see the laser with a NVG simultaneously.

 

You can detect the laser spot when it reflects energy to Laser Spot Warning sensor, that are in combat vehicles like MBT and modern IFV. So they know they are painted and would pop smoke and move in cover where they can't be painted. The smoke would as well scatter the laser energy, causing weapons to lose a lock and go dumb.

Examle AGM-65E and AGM-65E/2 (added capability for self-designation, since 2012 or so. While normal AGM-65E you can't self-designate) has safety feature that once the laser beam is lost, missile will perform hard vertical maneuver and disable it warhead (render it dud). This so that if you need to abort the weapon guidance, you can just shut off laser or quickly turn elsewhere and strike is cancelled.

 

So when a MBT pop smoke, laser is lost and your maverick goes crazy Ivan and is rendered useless.

 

If you launch AGM-65E for self-designation, the missile can cross the laser beam with it smoke and cause laser blocking and lose laser spot and go crazy....

[Rissala]

On 6/15/2021 at 12:32 AM, deathbysybian said:

Put a t-pod on to see where you're actually designating. 

I have a suspicion it's only accurate the moment it's drawn.  Since it can take several seconds to update the image it can be very far off.

well the point of the A-G radar is to be an all weather alternative to the good weather equipment

seems like the discussion jumped quite quickly to the assumption that the A-G radar is really supposed to have a 100 meter+ CEP
i just wanted to know if this is the case irl

 

 

edit: and it seems like it was

Edited June 23, 2021 by Rissala

[Swift.]

1 hour ago, Rissala said:

well the point of the A-G radar is to be an all weather alternative to the good weather equipment

seems like the discussion jumped quite quickly to the assumption that the A-G radar is really supposed to have a 100 meter+ CEP
i just wanted to know if this is the case irl

 

 

edit: and it seems like it was

 

The point of AG in general might be to produce all weather targeting. But the point of AG radar in APG-73  is closer to something like 'sell more radars'. Its notoriously poor, and even with ED overmodelling the hell out of it, its still poor to use in DCS.

[oldcrusty]

Here's my 'detailed' description of A/G radar integration...  It sucks.  Well, I can work with GMT or SEA modes, the modeling is lacking or in some cases too optimistic but it does the job for my needs.

After reading this thread I decided to try EXP3 scan on a big structure around Damascus. I had the WPDSG right on top of it and the ground radar was sharpening the picture in EXP3.

 I was actually impressed with the quality of the final scan before freezing it.  I had the ATFLIR on LDDI so I could see the target clearly.

I turned away slightly and the radar image snapped to a different orientation with TGT cross still in correct location. The FLIR stayed glued to the target.

The problem started when I tried slewing the radar cross to various, clearly visible objects on the radar image. Whether I should or shouldn't be able to do this... I don't know, I suspect I should.  The cross would snap back to original designation every time I moved it (could be an issue  with my WH TDC) but the FLIR went bonkers. With every press of the TDC on the radar map, the FLIR would jump to a different part of the city, never the same location. I couldn't figure out any pattern.  So, if the ground radar is not capable of re-designating on a frozen image, it shouldn't cause the FLIR to go stupid.

[Hammer1-1]

I can see the use in using MAP mode for the most part, but honestly I never intended to ever use it anyways. The most useful functions of the A2G radar is SEA and GMT, and even then GMT isnt all that great either unless you are operating in a poor country where nobody has a vehicle except the military.

[oldcrusty]

I tested Exp3 again and basically it is useless...  It takes too long to sharpen the image. Even if you wait that long, there's no way to tell what sort of object you might be looking at. I tried to focus on TU160 image and all I could see was a blob. Buildings or runways yea, I can see the features.

In one of my tests, I was patient enough to let the radar do a full EXP3 scan, while carefully maintaining the proper offset from the target. The image was OK, the problem was... by that time I was 5 nm from the target.

Now, the FRZ function doesn't freeze anything. Basically, once frozen it should be an image centered around the target (cross), rotating smoothly to show correct orientation from the jet.

The MC knows the coordinates of the cross. How hard would it be for the MC to extrapolate any other point on the frozen image if a different target within the image is designated.

Same as on SA display.

In this clip (starting at 1:00) the target is designated in EXP3 and the 'cross' jumps over to a different location when I turned away slightly.

 

 

[LastRifleRound]

This is not "correct as is". I have a confirmed bug report on this very issue.

 

INS ag radar designations are subject to a phenomenon called "map shift". This is because in an EXP mode, you aren't seeing what the radar "sees", rather a mathematical extrapolation of it. The equations used to render this have errors in azimuth that get smaller the larger pool of doppler data there is to work with.

 

What this means is that the faster, more off angle, and closer to the target you are, the more accurate your designation should become. It is within 100ft for the APG65. I do not know the value for the 73.

 

In DCS, the opposite is true. This is because map shift isn't modeled. What you are seeing is ED not adjusting properly for the aircraft's own movement between scans. You can test this with a FLIR and see the exact things that should make designations more accurate actually make them worse, and always in the same direction counter to the aircrafts angle off and direction of travel.

 

For a more extreme example (and also a separate, but related confirmed bug) use the FRZ mode to make a designation. The longer you wait to make a designation, the farther counter to the direction of aircraft travel the designation will be.

 

ED, I can find the links if need be, but I've reported this and had it confirmed twice months ago and months apart. I didn't want to be a pain and list it again because I can see you're still working on the AG radar.

 

Let me know if you want the links to the previous bug reports and please update the status of this report to some other than "correct as is".

 

EDIT:

Here's a link to one of the older reports that was confirmed. I forgot to mention you can further confirm the issue by going to active pause. Wait a few scans, then your designations will be 100% accurate because the aircraft isn't technically moving.

 

Edited June 22, 2021 by LastRifleRound

[Rissala]

On 6/22/2021 at 8:22 PM, LastRifleRound said:

This is not "correct as is". I have a confirmed bug report on this very issue.

 

INS ag radar designations are subject to a phenomenon called "map shift". This is because in an EXP mode, you aren't seeing what the radar "sees", rather a mathematical extrapolation of it. The equations used to render this have errors in azimuth that get smaller the larger pool of doppler data there is to work with.

 

What this means is that the faster, more off angle, and closer to the target you are, the more accurate your designation should become. It is within 100ft for the APG65. I do not know the value for the 73.

 

In DCS, the opposite is true. This is because map shift isn't modeled. What you are seeing is ED not adjusting properly for the aircraft's own movement between scans. You can test this with a FLIR and see the exact things that should make designations more accurate actually make them worse, and always in the same direction counter to the aircrafts angle off and direction of travel.

 

For a more extreme example (and also a separate, but related confirmed bug) use the FRZ mode to make a designation. The longer you wait to make a designation, the farther counter to the direction of aircraft travel the designation will be.

 

ED, I can find the links if need be, but I've reported this and had it confirmed twice months ago and months apart. I didn't want to be a pain and list it again because I can see you're still working on the AG radar.

 

Let me know if you want the links to the previous bug reports and please update the status of this report to some other than "correct as is".

 

EDIT:

Here's a link to one of the older reports that was confirmed. I forgot to mention you can further confirm the issue by going to active pause. Wait a few scans, then your designations will be 100% accurate because the aircraft isn't technically moving.

 

 

 

Newy sad that:

 

"Hi,

 

I do have the accuracy between the TPOD and the RADAR designation reported already

 

thank you"

 

So it is a bit disingenuous to say that the designation bug itself is reported.

 

However, the bug itself seems to be as you described:

 

With active pause enabled, the radar is 100% accurate. When the motion is taken out of the equation, the radar works. (too well?)
 

Is this just a lazy way to make the radar "limited" like in real life, OR is this there some code logic errors that ignore the movement of the Hornet when designating a TGT? I bet it is the latter one...

 

I unmarked the "solved" since the "correct as is" seems to not be the case afterall.

 

Maybe implement a random error after correcting for the A/C motion bug? This way the random error is tunable and can be tuned for a closer match with the real thing.

 

(or just sweep this under the rug and make it "correct-as-is" anyways?)

 

@BIGNEWY Can you have a last look at this? Pretty please?

 

Trackfile for the active pause 100% accurate designation is already in the thread shared by @LastRifleRound.

 

Thanks.

[LastRifleRound]

3 hours ago, Rissala said:

 

Newy sad that:

 

"Hi,

 

I do have the accuracy between the TPOD and the RADAR designation reported already

 

thank you"

 

So it is a bit disingenuous to say that the designation bug itself is reported.

 

However, the bug itself seems to be as you described:

 

With active pause enabled, the radar is 100% accurate. When the motion is taken out of the equation, the radar works. (too well?)
 

Is this just a lazy way to make the radar "limited" like in real life, OR is this there some code logic errors that ignore the movement of the Hornet when designating a TGT? I bet it is the latter one...

 

I unmarked the "solved" since the "correct as is" seems to not be the case afterall.

 

Maybe implement a random error after correcting for the A/C motion bug? This way the random error is tunable and can be tuned for a closer match with the real thing.

 

(or just sweep this under the rug and make it "correct-as-is" anyways?)

 

@BIGNEWY Can you have a last look at this? Pretty please?

 

Trackfile for the active pause 100% accurate designation is already in the thread shared by @LastRifleRound.

 

Thanks.

I think disingenuinous is a bit hyperbolic. They are clearly the same thing. Seeing as "FLIR difference bug" was never fixed, even if that were the issue this can't possibly be correct as is. I interpreted that as him acknowledging the issue especially in the context of myy previous bug report and the FRZ mode bug report are both confirmed also. I can dig them up if need be, I've already done it once.

 

1. The TPOD is on the designation spot, ie bombs go there

2. FRZ mode exacerbates the issue

3. FTT co-locates radar designation and FLIR designation

4. Minimizing angle off and speed improves designation

5. If you take the FLIR off and use the HUD, it also confirms this is the real designation spot.

 

Therefore, there is no difference between what the radar designates and where the FLIR goes. The FLIR is simply looking at the designation.

 

This is a bug, plain and simple. It's not simulating "general inaccuracy", as the radar is inaccurate in a very specific way. Documented methods of using the radar to bomb lead to the opposite result, IE making your last designation at 7nm, 450kts at 45 degrees angle-off is FAR worse than 20 degrees at 20nm. The performance is too good far away and too poor close in.

 

The user should be able to follow the TACMAN to achieve the best possible result. Right now, TACMAN ought to be ignored as it leads to the least optimal result.

 

Just how accurate it should be, I don't know. Again the -65 says 100ft. The problem isn't how inaccurate it is, it's that it should be at it's most accurate when it's at its least.

[Frederf]

Hey, this got a bit better from the last time I looked. The geometric transformations have improved but aren't good enough yet. It looks like they have most of the translation fixed but not rotation. When you designate the surface radar you're picking a spot based on the coordinate system at the moment of designation which is not exactly the same as the coordinate system suggested by the rasterized radar image on the display. As such there's an out-of-syncness that changes dynamically and is worse the farther away the designation is from the pivot point.

 

You can see it while simply viewing a designation in EXP1, the cross symbol is moving smoothly and differently compared to the sequential frames of radar image. The cross slides across the ground and seems to move relative to the image but if it was for example designated on a factory building it would keep showing up directly over that factory building on every fresh frame wipe. The radar is being perfectly accurate but the coordinate grid and images are behaving in a funny way having periodic waves of disassociation.

 

The center of interest (previous designation) seems to be at the center of any odd rotation or translation effects and not distorted. If you keep designating repeatedly on the previous target you never get an unexpected jump. The farther toward the edges of the display the less good the geometric transforms are about getting what you asked for. This makes it an iterative process to change radar target. Each time you designate you move your final solution close to the center of the display and make each successive designation closer to the piece of radar image you put the cross on.

 

What hasn't been dealt with at all yet is radar freeze. With radar freeze the radar imagery and its associated coordinate grid are both halted which allows the pilot to designate against the imagery accurately without using the radar anymore. For example at 20nm you can pop up from low altitude flying, get one scan of the target area in freeze, drop back down and then find your target in the radar image before making a final attack. Right now in DCS that's not possible as the designation you make against a frozen image is using the current grid instead of the one that was saved with the image freeze. You designate something 5 minutes after freeze frame and your designation is miles and miles away from what you want because you're miles and miles away from where you were.

 

The expand modes are acting like mini-freeze events, getting snapshots of imagery overlaid on a semi-compensated but still dynamic coordinate system. The imagery and grid are doing different things enough that the designation isn't where you put the cross visually.

 

The radar itself is very accurate. This is the result of designating an AAV-7 from 30nm away using EXP3 while in active pause.

As you can see accuracy is not so bad at all. Azimuth accuracy is the hardest as tank targets seem to have 3-5 dots wide appearance in EXP3 that don't show up in 1/2 (like ..oo0oo.. ) The whole scene is kinda triple layered and shifted in the tangential direction. All the Doppler sharpening imagery is best at 45 degrees either side of the nose, 30-50 degrees is OK. Beyond 55 degrees the radar hits a limit bad things happen. What's hard is that without active pause what you designate on the image is not what you get. Remember to always wait up to 2 frame wipes to see what your designation did. I have a bad habit of dropping holding the depress early and immediately pressing the TDC again is a bad idea, you get "double jumped". If your finger slips let it do a couple wipes to see where you ended up. I also find that EXP3 gets stuck a lot. It can be hard to tell if it's still updating because the wipe line is subtle when the images look almost identical. If I suspect then I'll go EXP2 then back to EXP3 to force it to refresh.

 

 

This is the result of a 20kft ~10nm designation in EXP3 with a pair of GBU-32s. I admit that I took a few stabs at this. my first try hit ~50m short and the next just clipped the corner. It seems in EXP3 the image is smeared in azimuth a bunch and you should bias the designation toward the nose side and the far edge. A few trial runs would help nail down the systematic offset. I compared the airfield building smudges to the runway outlines to try to see if there was a pattern to it. The radar image takes a bit of interpretation. Taxiway intersections are crystal clear though. It is objects with height that get more abstract.

[Rissala]

This is my .trk that also shows the accuracy when using active pause or in other words eliminating the motion of the Hornet.

 

I hope ED can reproduce this.

 

I can provide more tracks showing the inaccuracy when not using active pause.

 

A-G radar accuracy try #1.trk A-G radar accuracy ACTIVE PAUSE #1.trk

A-G radar accuracy ACTIVE PAUSE #2.trk

Edited June 24, 2021 by Rissala

[Rissala]

Well these 2 pics sum it up. When in active pause, as @LastRifleRoundsaid, the designation is accurate.

When moving, the code is bugged so the designation is not accurate.

 

It all has to do with the map updates on the MFD and the motion of the Hornet or something like that.

 

Active pause designation:

 

 

 

 

Moving designation:

 

 

"Hey, this got a bit better from the last time I looked. The geometric transformations have improved but aren't good enough yet. It looks like they have most of the translation fixed but not rotation. When you designate the surface radar you're picking a spot based on the coordinate system at the moment of designation which is not exactly the same as the coordinate system suggested by the rasterized radar image on the display. As such there's an out-of-syncness that changes dynamically and is worse the farther away the designation is from the pivot point. "

 

This sums it up.

Edited June 24, 2021 by Rissala

[Rissala]

Well I will abandon this thread for now. I can't really think of any new evidence to prove this bug than what has already been told here. Still kinda sucks that 0 visibility designation is still kind of useless but I hope this gets some attention some day.

[LastRifleRound]

I wouldn't mark it off as a solution, it's not solved. Thread should stay open and be addressed.

 

@Frederfis right about what is likely happening here. It is likely not intended. I will test this weekend, but if he's right, they've been working on it. @Santi871 it would be great if you could take a second pass at this. We provided some solid evidence here that this isn't working correctly.

[oldcrusty]

Currently, if anyone really needs to use EXP3, it helps tremendously if the scan initiates say at 45, 47 deg. offset, followed by a very mild bank toward the target. If your jet is level or banked opposite way, even a single degree... no dice.  The 'freeze' function kinda worked...  it did freeze the snapshot and kept it there until I flew few miles past the target. The image didn't move in a stable flight, unless the jet maneuvered violently or egressed the target area, so... it is still effected by radar updates somehow.