HARM over the horizon shooting?

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jarraya
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HARM over the horizon shooting?

Post by jarraya »

When playing one of the scenarios I had my SEAD a/c flying NoE and was able to fire an anti radiation missile over the horizon.
Plotting the data into a quick horizon calculator, assuming a radar mast height of 10 m and a flying altitude of 91 m (300 ft) I was still able to fire my AGM-88 at max range, 100+ km.
Is this realistic or would you consider this an exploit?
bpstalker
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RE: HARM over the horizon shooting?

Post by bpstalker »

is this really realistic that a harm like missile launched at sea level would fly 100km?
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Clockmaster77
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RE: HARM over the horizon shooting?

Post by Clockmaster77 »

According to Wikipedia the AGM-88 range should be 150km:

https://en.m.wikipedia.org/wiki/AGM-88_HARM

"History is the only discipline that is studied not to be repeated."
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SeaQueen
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RE: HARM over the horizon shooting?

Post by SeaQueen »

I'm not necessarily against it. HARM has lots of modes and lots of different versions. Some of them can probably do that. HARM is a lot more capable than Standard ARM or Shrike.
AKar
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RE: HARM over the horizon shooting?

Post by AKar »

ORIGINAL: Clockmaster77

According to Wikipedia the AGM-88 range should be 150km:
TBH I doubt it would do nearly 150 km if launched from sea level. Range of any air-launched missile is extremely dependent on the launch geometry, velocity of the launch platform and on the launch altitude. In particular, in case of air-to-air launches, the best case scenario may very easily have five times the range from which the target can be reached than the worst case would. In case of HARM, large amount of the energy added by the rocket burn is wasted struggling to accelerate and climb in dense near sea level atmosphere, and the glide to the target would therefore be hampered by comparatively low maximum velocity and altitude of the missile at the moment of rocket burn-out.

In what comes to launching HARM to an emitter it does not have a line-of-sight into; the HARM can be launched in POS mode (I understand typically in PB, or pre-briefed mode), where the position of the launch platform and the target are loaded into the missile before the launch. In other words, the missile does not need to 'see' the emitter at the moment of launch, or prior to it.
jarraya
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RE: HARM over the horizon shooting?

Post by jarraya »



[/quote]

In what comes to launching HARM to an emitter it does not have a line-of-sight into; the HARM can be launched in POS mode (I understand typically in PB, or pre-briefed mode), where the position of the launch platform and the target are loaded into the missile before the launch. In other words, the missile does not need to 'see' the emitter at the moment of launch, or prior to it.
[/quote]

I guess in that case CMANO is wrong because the missile can still "see" the emitter OTH. If you manually attack you will get a green light to shoot, even when you are below the horizon, meaning that the target emitter is visible to the missile.

I don't like to use exploits (which I think this is one) so I will just role play this out - if I want to shoot from 300 ft. then I must be about 28 nautical miles from the target or I need to use a bearing only launch (not sure if that is allowed for these missiles).

It would be great if these calculations were done by the system, as well as limiting range based on fuel/altitude as per your post.
Kobu
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RE: HARM over the horizon shooting?

Post by Kobu »

The HARM can be launched in PB mode where its not necesarry detect the radar emissions of the target, the HARM goes to a point and there active his seeker and seek for the radar´s emissions. Here the problem or limitation is that for launch the HARM from very low altitude it should not have all of his range.


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AKar
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RE: HARM over the horizon shooting?

Post by AKar »

ORIGINAL: Kobu

The HARM can be launched in PB mode where its not necesarry detect the radar emissions of the target, the HARM goes to a point and there active his seeker and seek for the radar´s emissions. Here the problem or limitation is that for launch the HARM from very low altitude it should not have all of his range.
Yes, precisely. You don't need to see the emitter for a valid HARM shot. A successful hit would of course benefit from high-confidence target information, but this needs not to come via HARM's sensor, nor via AN/ASQ-213 for instance.
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Clockmaster77
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RE: HARM over the horizon shooting?

Post by Clockmaster77 »

ORIGINAL: AKar
In case of HARM, large amount of the energy added by the rocket burn is wasted struggling to accelerate and climb in dense near sea level atmosphere, and the glide to the target would therefore be hampered by comparatively low maximum velocity and altitude of the missile at the moment of rocket burn-out.

Command models mach number variations at altitude (as seen in the database aircraft entries at the engine "Performance Details", with fuel consumption variations for various altitudes, speed, and mach number). The same entries are present in the DB for Weapons, and so for AGM-88 Harm.

It takes into consideration air density variation also for air friction, and for missiles, and after burnout in the glide phase? I don't know that. I would think yes, since dumb bombs, that are gliders, are modeled. If these things are modeled, the 100km radius noticed by jarraya at sea level should be considered realistic, excluding some bug.
If not... Well, hoping it will be updated soon.
But only developers can answer this question.
Bye [:)]
"History is the only discipline that is studied not to be repeated."
Cik
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RE: HARM over the horizon shooting?

Post by Cik »

yes, you can fire HARM OTH, with a number of pre-planned target modes (PB/EOM) granted, you'd have to have a known target (or suspected target location) the waypoint doesn't actually have to be technically pre-briefed, as most modern jets support after-T/O steer/markpoint creation via UTM/MGRS/latlong/etc.

now, this isn't actually simulated to any real degree IIRC (unless you simply use cntrl+f1 and shoot at the ground) but it's at least possible.
AKar
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Joined: Sun Mar 18, 2018 8:38 am

RE: HARM over the horizon shooting?

Post by AKar »

ORIGINAL: Clockmaster77
ORIGINAL: AKar
In case of HARM, large amount of the energy added by the rocket burn is wasted struggling to accelerate and climb in dense near sea level atmosphere, and the glide to the target would therefore be hampered by comparatively low maximum velocity and altitude of the missile at the moment of rocket burn-out.

Command models mach number variations at altitude (as seen in the database aircraft entries at the engine "Performance Details", with fuel consumption variations for various altitudes, speed, and mach number). The same entries are present in the DB for Weapons, and so for AGM-88 Harm.

It takes into consideration air density variation also for air friction, and for missiles, and after burnout in the glide phase? I don't know that. I would think yes, since dumb bombs, that are gliders, are modeled. If these things are modeled, the 100km radius noticed by jarraya at sea level should be considered realistic, excluding some bug.
If not... Well, hoping it will be updated soon.
But only developers can answer this question.
Bye [:)]
Missile kinematics in CMANO as of today are not always quite accurate. Can't remember how the HARM was but I'm going to play around with it some trying King of the Border this weekend. :) Generally speaking, such dual thrust rockets employ a boost phase which burns out in just a few seconds and a lower thrust sustain phase that usually burns out in few tens of seconds, tops. After that, the thing is a very poor glider, bleeding off energy like crazy. A sea level launch would not allow the missile to reach an efficient flight profile, and will probably leave it at relatively low velocity, low altitude situation after the rocket motor sustainer phase commences, having drastic impact on the achieved energy before sustainer phase burnout, and thereby on the maximum range it can reach.
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