Does POS-RUK mode for HARMs work well on BMS?
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…… In both EOM and PB the HARM doesn’t go active until 5nm from the STPT, IIRC. The only two differences I can find between EOM and PB are the FOV and lofting cues in PB.
Just a bit of a correction on when the seeker goes active in the different POS sub-modes:
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Each mode controls at which point the missile will activate its seeker and what will be the seeker’s FOV. The most accurate mode is EOM. It will activate the seeker at 5NM from the handed-off steerpoint with a 40 deg FOV. This mode should only be used when the location of the emitter is well-known—i.e., emitter position collocated with a steerpoint. In PB mode, the seeker will activate at 15NM from the handed off steerpoint with a 120 deg FOV. This mode should be used when the position of the emitter is relatively close to the steerpoint. In the last mode, RUK, the seeker is activated immediately after launch with a 120 deg FOV. …
https://www.benchmarksims.org/forum/content.php?154-No-HARM-No-Foul-A-New-Way-of-Destroying-Radars
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Sorry but the logic is pretty clear to me
The missile must have a flight profile off the rails
If the flight profile is always without loft you will tell me that in RUK you arenunable yo hit 50nm distant threat
So it makes sense to me to tell the missile which flight profile it should apply.and this is done by.STP selection
And about the logic FYI we didnt invent it , we implemented the real logic as close.as we could /know
Ok, i will try again also selecting an stp behind me, to see what happens.
By the way, when you suggested about using a markpoint, were you referring to using an OVERFLY markpoint right? I can´t imagine how to set a TGP or FCR markpoint if i don´t know the location of the SAM site, with the exception of aproximate direction. -
Ok, i will try again also selecting an stp behind me, to see what happens.
By the way, when you suggested about using a markpoint, were you referring to using an OVERFLY markpoint right? I can´t imagine how to set a TGP or FCR markpoint if i don´t know the location of the SAM site, with the exception of aproximate direction.From mission planning u will know where the SAM will be so put a point and it will show on HSD… even if it’s moving it will be near there.
If u fire it having a STPT behind u it will go buzinca… -
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well,there is a way of knowing the exact coordinates of an unknown SAM, using the HAD(for range and bearing), an OFLY markpoint, the VRP option and some distance conversion calculations.
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Not necessarily. I have done it.
Yes but this is luck. U want it to go by luck or know what u r doing and expect a good result?
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Yes but this is luck. U want it to go by luck or know what u r doing and expect a good result?
It’s not luck with RUK mode. I have done it with surprising consistency.
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Ok, i will try again also selecting an stp behind me, to see what happens.
By the way, when you suggested about using a markpoint, were you referring to using an OVERFLY markpoint right? I can´t imagine how to set a TGP or FCR markpoint if i don´t know the location of the SAM site, with the exception of aproximate direction.I’d use the HUD markpoint sub-mode, I think. Just pick a spot some good ways out in front of you for the HARM to initially ‘latch’ to as far as range.
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The missile must have a flight profile off the rails
If the flight profile is always without loft you will tell me that in RUK you arenunable yo hit 50nm distant threat
POS-RUK turns the seeker on while on the rail. HAS also turns the seeker on the rail and does not have STPT flight profile off the rail.
I can only reverse engineer speculate on how the RUK or HAS ranges a locked target while on the rail to create a loft.1. It uses right angel triangle trigonometry. One angel (slant angel) and one leg (altitude). Lock a target in HAS, it shows were the target is in it’s FOV.
2. The pilot determine the loft. There is no computerize loft program. I doubt irl that RUK uses a STPT. Pilot just a lines the jet with the RWR.
Sorry but the logic is pretty clear to me
You don’t understand the situation. If your current STPT is 70nm away and a SA-6 pops up 10nm off your nose you can’t hit it with POS-RUK. Does that sound like a self protect mode?
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Ok, i will try again also selecting an stp behind me, to see what happens.
By the way, when you suggested about using a markpoint, were you referring to using an OVERFLY markpoint right? I can´t imagine how to set a TGP or FCR markpoint if i don´t know the location of the SAM site, with the exception of aproximate direction.First you have to call for a “time out”. You don’t want SAM flying at you while you are trying MARK STPT with just a RWR bearing.
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POS-RUK turns the seeker on while on the rail. HAS also turns the seeker on the rail and does not have STPT flight profile off the rail.
I can only reverse engineer speculate on how the RUK or HAS ranges a locked target while on the rail to create a loft.RUK stands for “Range Unknown,” it does not range a locked target, and the seeker does not come on while on the rail. In RUK mode the seeker comes on after launch (BMS manual page 99). Record an ACMI and you can see this in action: The missile will initially steer towards STPT immediately at launch but changes direction if/when it detects the threat you handed off. RUK is also described as a “degraded state of EOM” and, EOM being STPT dependent, would explain the logic that Mav-jp is talking about.
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RUK stands for “Range Unknown,” it does not range a locked target, and the seeker does not come on while on the rail. In RUK mode the seeker comes on after launch (BMS manual page 99). Record an ACMI and you can see this in action: The missile will initially steer towards STPT immediately at launch but changes direction if/when it detects the threat you handed off. RUK is also described as a “degraded state of EOM” and, EOM being STPT dependent, would explain the logic that Mav-jp is talking about.
I believe RUK is NOT STPT dependent. That why it’s described a “degraded state of EOM”.
It also says that RUK is used for Target of Opportunity – TOO. To me that mean that the target can be off flight plan. -
I believe RUK is NOT STPT dependent. That why it’s described a “degraded state of EOM”.
It also says that RUK is used for Target of Opportunity – TOO. To me that mean that the target can be off flight plan.What you’re saying seems sensible, but here is what I don’t understand in your explaination:
@HARM:
…. In the last mode, RUK, the seeker is activated immediately after launch …
There is a certain amount of time from pickle, to launch, to the seeker going active, to seeker finding a target …. maybe the time is smaller or a bit larger depending on when the seeker finds a target. Where is the missile flying to during this time between launch and target acquisition?
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I believe RUK is NOT STPT dependent. That why it’s described a “degraded state of EOM”.
It is “degraded” because it has a wider FOV, the seeker activates immediately after launch, and range of the target is completely unknown, making it less accurate. EOM and PB are used when the target is known to be in the general vicinity of a STPT, therefore giving at least a good estimation of range. The seekers also activate much closer to the STPT/target, making them more accurate.
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I’ll try one more time. The way RUK is coded in BMS:
When the current STP is >60nm it is coded to do a loft program even when the seeker locks on a target a short range. And the HARM goes up to 30k feet or it hits behind the target.The code is real close. If the STP is <30nm from the a/c not the target(STP can be behind your a/c), the missile will fly LOS to the target.
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RUK is the same as HAS(both range unknown/target of opportunity modes). so use HAS better. u dont want the HARM to go active ASAP since it searches a larger geographical area making it susceptible to a miss or an impact somewhere within the Missile Impact Zone.
RUK is LOAL, HAS is LOBL.
POS-RUK turns the seeker on while on the rail. HAS also turns the seeker on the rail and does not have STPT flight profile off the rail.
I can only reverse engineer speculate on how the RUK or HAS ranges a locked target while on the rail to create a loft.1. It uses right angel triangle trigonometry. One angel (slant angel) and one leg (altitude). Lock a target in HAS, it shows were the target is in it’s FOV.
2. The pilot determine the loft. There is no computerize loft program. I doubt irl that RUK uses a STPT. Pilot just a lines the jet with the RWR.
You don’t understand the situation. If your current STPT is 70nm away and a SA-6 pops up 10nm off your nose you can’t hit it with POS-RUK. Does that sound like a self protect mode?
RUK is LOAL, HAS is LOBL.
RUK, PB, EOM are all three POS modes and all POS modes are steerpoint-directed in azimuth. The difference is in end game seeker activity and assumed range only. EOM and PB assume range = range to steerpoint. RUK assumes range = maximum.
EOM = point
PB = area
RUK = laneI agree. RUK is for painting a long, wide stripe of ground with HARM coverage. PB is for a floodlight on an area. EOM is a laser pointer. I tried the HARM TE with RUK against the same 56-59 STPT as the SA-3. I prepared the missile and drove into the SA-3 at medium altitude. When SA-3 launched I launched and RUK HARM were pretty bad at acquiring it and the STPT was co-located with the SA-3! BTW in RUK the steerpoint only gives direction, not range. If you fire two RUK HARM at two steerpoint both the same bearing but different range (say 10nm, 100nm) the missiles behave identically RUK is lofting for maximum area covered along a given direction.
There exist self-protect modes of HARM which are not steerpoint related, even get their threat and direction data from RWR, but not in BMS or F-16.
EDIT: Whee, I was wrong. Apparently RUK is range-to-steerpoint dependent. More testing shortly. Imagine the yellow text is strike-through. I wish this board used the tags.
Test#1: RUK against 30 and 50nm steerpoint in line, deliberately set threat to SA-6 so it wouldn’t go active on a 2-3-4 present. Farther steerpoint resulted in higher profile. Surprisingly RUK short shot seemed to run out of steam right over the near steerpoint and likely wouldn’t have been able to engage any threat significantly beyond.
Test#2: EOM short range (<10nm) at 180, 135, and 90 degrees off axis. Engaged SA-3 from limit of PPT circle with three EOM shots released approx 15,000’. None did significant turning toward EOM steerpoint. Showed “inertial, lost target” in external view label. Expected EOM to have off-axis capability easily in this scenario.
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I just did a test myself. I set STPT5 at an SA-2 site and STPT6 approx. 70nm beyond the SA-2. I called up RUK and selected the SA-2 and STPT6, put the FPM on the SA-2 site (you can see a smoke plume in my HUD shot) and fired. The HARM flew right over the SA-2 and headed direct to STPT6.
While defensive I called up RUK again, selected SA-2 and STPT5 this time. Fired and killed the Fan Song.
If the seeker activates immediately after launch and the target was well within the seeker’s FOV, why did it ignore the target right in front of it?
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RUK is LOAL, HAS is LOBL.
RUK is LOAL, HAS is LOBL.
RUK, PB, EOM are all three POS modes and all POS modes are steerpoint-directed in azimuth. The difference is in end game seeker activity and assumed range only. EOM and PB assume range = range to steerpoint. RUK assumes range = maximum.
I agree. RUK is for painting a long, wide stripe of ground with HARM coverage.
Seeker going to lose search width with loft angle. FOV is 45* (from tecref). Take your flashlight and point it up as if it is a missile in a loft profile and see how much coverage is on the floor. I doubt if RUK goes for max range via lofting.
I don’t care if RUK LOBL or LOAL a micro second after launch. I can see advantages if it did/could lock on the rail.
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Frederf, could you please tell me what “LOAL” and “LOBL” mean? I was following the discussion well and with a lot of interest but i got lost there. :(.
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i think the problem is not the avionic on the F-16, not even the symbology, i think the problem is the agm-88 itself in BMS.