fixed HARM combined with HAD POS EOM and Logic

[Hobel]

I have now observed a few times that the Agm88 flies to destinations that were not handed over to it so I have tested the whole thing again and uploaded it in a track.

 

Am I doing something wrong here or  Why is the Harm not flying at the target I am aiming at?

 

 

F16 and Harm.trk

[Grodin]

Not sure if it is intended, but it appears HARM missiles home on the strongest (closest) signal of the selected type. Since you have multiple radars of the same type in a relatively small area, they all home in on the closest one first. I replayed your mission, and after killing the closest SAM they home in on the next.

[Hobel]

Yes, but shouldn't the harm first fly roughly into the target area before going to other radar positions?

[Raptor9]

It depends on what mode you are launching the HARM in. HAS, POS-RUK, POS-PB and POS-EOM all have different trajectories, phases of flight they turn their seeker on, and the FOV of the seeker.

This is my understanding of the different modes...

- HAS: you are locking on to an emitter before launch, but using a less energy-efficient trajectory.

- POS-RUK: you are launching on a bearing and the seeker comes alive shortly after launch in a wide area search, which means it may lock on to the selected emitter type almost immediately, lose some of it's energy-saving trajectory, and may hit a different emitter along that bearing.

-POS-PB: you're launching toward a pre-planned target area with reasonable certainty that an emitter of the type you are targeting is in that area, allowing you to launch further out since the missile flies in a more energy-efficient trajectory to the target. However, like RUK mode, the missile searches in a wide area and may not hit the specific emitter you intended, but is more likely since the seeker comes online closer to the target area.

-POS-EOM: just like PB, however this is used when launching at the known location of the emitter you are targeting. Uses an energy-saving flight trajectory, but uses a more narrow search area when the seeker comes online in the terminal phase due to the higher confidence of the emitter location.

If anybody has a more solid understanding on this topic, specifically any additional considerations to how the HTS/HAD targeting method affects these modes, please jump in.

Edited December 17, 2021 by Raptor9

[Hobel]

5 hours ago, Raptor9 said:

It depends on what mode you are launching the HARM in. HAS, POS-RUK, POS-PB and POS-EOM all have different trajectories, phases of flight they turn their seeker on, and the FOV of the seeker.

that's exactly what i thought too i tested them all  modis and found that there was no difference in behaviour in this scenario

Preferably, however, the EOM mode.

However, the AGM88s also seem to switch on in EOM mode directly after start-up or too early, which is why they point to the same target.

So it would be interesting to know when the AGM88 actually switches on in EOM mode in RL?

 

Edited December 17, 2021 by Hobel

[TEOMOOSE]

If i remember correctly the differences between the 2 "best" position modes (PB and EOM) are the Field of View and when the harm radar turns on. For example in "PB", the Harm radar turns active 15-20 nmi from waypoint and starts searching at a FOV of 120° degrees and in "EOM" the Harms radar turns on at 5 nmi from the waypoint and starts searching at a FOV of 40° degrees.

[Hobel]

2 hours ago, TEOMOOSE said:

 in "EOM" the Harms radar turns on at 5 nmi from the waypoint and starts searching at a FOV of 40° degrees.

And that is definitely not the case, do you have a source for the figures?

[Frederf]

I have found that all HARMs trip very shortly after launch and will track other than the designated target regardless of mode.

[TEOMOOSE]

37 minutes ago, Frederf said:

I have found that all HARMs trip very shortly after launch and will track other than the designated target regardless of mode.

What do you mean ?

[Frederf]

If you fire a POS shot at a location (say without an emitter) ~35nm and there is a threat radar of the assigned type ~30 degrees off axis laterally from the airplane-location line the missile will fly toward the active emitter within 2 seconds after launch. This applies to all POS shots: EOM, RUK, PB.

[TEOMOOSE]

This is has to do with the Field of View. At a greater distance you the radar will see more within the Field of View depending on the mode it was fired. So its hard to test it, because you will have to be either close to a target sam, or try flying way off axis where you are outside of that FOV.

Im very interested to see the results of your test.

[Frederf]

Real HARMs have trip points. A 40 mile EOM shot shouldn't be forgetting its mission 2 seconds off the rail. It has nothing to do with FOV.

[TEOMOOSE]

1 hour ago, Frederf said:

Real HARMs have trip points. A 40 mile EOM shot shouldn't be forgetting its mission 2 seconds off the rail. It has nothing to do with FOV.

I think you miss understood what i said. Perhaps a tacview if you have any to look at.

[Kilo]

8 hours ago, Frederf said:

Real HARMs have trip points. A 40 mile EOM shot shouldn't be forgetting its mission 2 seconds off the rail. It has nothing to do with FOV.

I think that should be solved by the Geospecificity and Target Isolation modes that will be implemented later on.

[Frederf]

nah, even full flex it shouldn't go squirrel off the rail. TI is for other types. GS is for trajectory shape.

[JabbyJabara]

ED,

What is the point of these modes and the HAD if your HARMS do not follow the logic of targeting separate sensors. EOM search field is supposed to be a narrow FOV and the POS PB is a wide FOV. I separated via steerpoints with one scenario and another with the HAD system. they all tracked the same SA6 regardless of others being separated by more than 10nm

[JabbyJabara]

HARM Logic Error.trk

Tacview-20220319-072554-DCS.zip.acmi

[Hobel]

About the problem there are already several topics and reports

Raptor9 here almost the actual functionality again very nicely together

 

 

[Koozie]

Yeah I can confirm something is not right.  I used this mission from the track.  Fired HAS - PB at the 3 furthest ones and they all targeted the closed middle one.  I had to turn the jet to get inside the PB wez first before each shot.  

I went back and tried it with this same mission in POS, EOM and PB. Even though I change waypoints for PB and turn the aircraft to get in perm for the shot, the HARMS track to the closest middle SAM.  Seems to be a POS bug that also lives in the HTS post.  HAS works fine. 

 

HARM POS Not working.trk

Edited March 22, 2022 by usafcop11

[BIGNEWY]

topics merged, reported

thanks