reported RADAR still tracks locked target even if FCR switch turned off

[djacd]

The F-16 RADAR will still track a locked target after the FCR displays OFF on the MFD and the FCR switch is turned off.

4:27 mark of this video illustrates it.

 

[BIGNEWY]

Hi, 

I will check with the team, please if possible include a short as possible track replay example from dcs

 

thanks

[djacd]

5 hours ago, BIGNEWY said:

Hi, 

I will check with the team, please if possible include a short as possible track replay example from dcs

 

thanks

Sure no problem, here you go.

F-16 Tracking Continues Tracking After FCR off.trk

[BIGNEWY]

Hi 

We are not seeing any issue here.

The diamond in the video is the steerpoint marker that happens to be along the same LOS as the target.

[Default774]

On 10/18/2022 at 8:30 PM, BIGNEWY said:

Hi 

We are not seeing any issue here.

The diamond in the video is the steerpoint marker that happens to be along the same LOS as the target.

@BIGNEWY While your assessment that the steerpoint diamond is over the target is correct, there is without a doubt an issue with the FCR power switch and the radar holding tracks.
By turning off the FCR power the plane will magically keep track of where the targeted jet is without needing radar illumination for roughly 60 seconds.

This means you can fire a missile, turn the FCR power off, and then do whatever you want. The missile will get magic midcourse guidance from the jet even if you turn cold. The HUD indications will not change, but this doesn't matter, the jet still knows where the target is in the background.

As demonstrated in the trackfile, I fire a missile, turn the FCR power off and then turn cold, the target is no longer being illuminated by my radar. Yet, my missile, almost 180 degrees behind me, is receiving midcourse guidance updates. The target aircraft is set to make a slight left turn about halfway through the midcourse stage of the missile. If the missile was in INS or receiving false midcourse guidance info, the missile would go for empty air and miss. However, the missile keeps guiding perfectly, as if I was supporting it all the way conventionally.

Additionally, I fire an AIM-120 about 180 degrees off bore when I am fully cold, you can see the missile attempt to do a complete 180 trying to get to the target.

magic_midcourse.trk magic_midcourse.acmi

Edited October 19, 2022 by Minimalist

[BIGNEWY]

13 hours ago, Minimalist said:

@BIGNEWY While your assessment that the steerpoint diamond is over the target is correct, there is without a doubt an issue with the FCR power switch and the radar holding tracks.
By turning off the FCR power the plane will magically keep track of where the targeted jet is without needing radar illumination for roughly 60 seconds.

This means you can fire a missile, turn the FCR power off, and then do whatever you want. The missile will get magic midcourse guidance from the jet even if you turn cold. The HUD indications will not change, but this doesn't matter, the jet still knows where the target is in the background.

As demonstrated in the trackfile, I fire a missile, turn the FCR power off and then turn cold, the target is no longer being illuminated by my radar. Yet, my missile, almost 180 degrees behind me, is receiving midcourse guidance updates. The target aircraft is set to make a slight left turn about halfway through the midcourse stage of the missile. If the missile was in INS or receiving false midcourse guidance info, the missile would go for empty air and miss. However, the missile keeps guiding perfectly, as if I was supporting it all the way conventionally.

Additionally, I fire an AIM-120 about 180 degrees off bore when I am fully cold, you can see the missile attempt to do a complete 180 trying to get to the target.

magic_midcourse.trk 185.87 kB · 2 downloads magic_midcourse.acmi 93.93 kB · 1 download

 

We have a related report fixed for the next patch. I will suggest you wait for the patch and test again but I am not seeing any issue. 

The AIM-120 fly's the predicted path to the target from the initial lock and launch at Rmax, when you go cold / radar off the target aircraft is still in the seekers FOV. 
Try it with a manoeuvring target and see if you notice the same.

[Default774]

3 hours ago, BIGNEWY said:

We have a related report fixed for the next patch. I will suggest you wait for the patch and test again but I am not seeing any issue. 

The AIM-120 fly's the predicted path to the target from the initial lock and launch at Rmax, when you go cold / radar off the target aircraft is still in the seekers FOV. 
Try it with a manoeuvring target and see if you notice the same.

I think you are misunderstanding what my track shows.

The target in my track is manoeuvring. If you were to perform the same shot in my track and either don't turn the FCR power off, or make the radar lose track normally, the missile will miss.

As I mentioned in my earlier post, my target is set to make a turn halfway through the midcourse phase. By the time I am cold to the target the turn hasn't been made yet, so how is my plane supposed to know that the target has made said turn? My radar can't see him, so how does my plane still know his position? If it was simply extrapolating, it would extrapolate the target at it's last known trajectory, which is it going straight. The missile would then get midcourse guidance information which is completely incorrect, and proceed to go active looking for a target that isn't there(the target has made a left turn). The DCS 120 has extremely tight parameters for acquiring a target on INS, even a 10-20kt difference of speed after the missile is on INS means the missile doesn't acquire the target, so it's not coincidentally acquiring it at the edge of the seeker FoV either(you would be able to tell, the DCS AIM-120 snaps like crazy when it acquires a target when on INS).

The seeker of the missile doesn't come into the equation at all here, as it hasn't even turned on yet. The DCS aim-120 doesn't have HUSKY/HPRF, so that's not it either.

What is actually happening is that when you turn the FCR power off, it doesn't actually drop the track in time. When you lose track normally by for example going out of gimbal limits, it takes exactly 8 seconds before the track is dropped. The FCR switch only drops the track after about 60 seconds. The HUD symbology doesn't update, but none of that matters, as in the backend my plane still has a live track of the targeted aircraft, without actually having any possible way of knowing this. This in practise means that you can fire a missile and have the missile get completely perfect midcourse guidance updates, despite my plane having no possible means to know what the targeted plane is actually doing, the radar is completely powered off after all.

Hopefully this explanation is more clear, but it seems the issue is already reported/fixed internally. I can attach more tracks later if it's still needed.

[Krippz]

This issue has been reported.