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Old 09-10-2019, 02:14 PM   #1
joojoo
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Hello to all

After all I managed to do some trials with the Harpoon antiship missile and despite that I have seen all the youtube tutorials I still have some unanswered questions.

1. Have we to take into account if the ship is on course or static? in what way we can calculate the bearing of the missile if the ship is on course?

2. Is there a right bearing that we can fire the missile in relation to the ship's bearing? for instance if the ship's bearing is 360, the appropriate firing is at the same bearing? what if I fire the missile with a missile's bearing preset at 90 right?

thanx
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Old 09-10-2019, 03:33 PM   #2
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1. You will have to lead a moving target. I've noticed the harpoon can tolerate at least +/- 10 degrees of error when it reaches radar range, so you don't have to be exact. Moving closer makes it easier (at 10 miles the missile will practically lock on immediately when fired, and this is still outside SAM range)

2. The bearing that you enter is the target's bearing relative to you. So, if the ship is directly north of you, 0 degrees, if south, 180 degrees. Dunno if it's true or magnetic, though. I've just been using the default heading tape on the HUD and it seems to work.

edit: I guess if you wanted to be precise, you could estimate the target's speed and calculate how far the ship will move during the time of flight. For reference, the harpoon goes about 10 miles in 1 minute.

Last edited by Preendog; 09-10-2019 at 03:38 PM.
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Old 09-10-2019, 04:11 PM   #3
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Dear Preendog

Thanx for your response. So in what bearing I have to preset the bearing of the missile if the ship is on 312 course and moving? Thanx
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Old 09-10-2019, 04:56 PM   #4
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The ships bearing from you is 312? ie. the RWR spike from the ship, if any, is 312 on your compass tape.

Lets say you want to shoot from 40 miles. The ship is moving, heading 100 at 30 knots (to the right from your point of view)

40 miles will take about 4 minutes. The ship will move 2nm in this time.

As a right triangle (it's not, but close), the longest side is 40nm (range), and the far side is 2nm (amount ship moves to your right).

ATAN 2/40 is 3.2 degrees. I would aim at 315.

It's not very much difference unless the ship is going really fast or you shoot from really far away. If the ship is mostly moving toward or away from you, no lead is needed.



Last edited by Preendog; 09-10-2019 at 05:32 PM.
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Old 09-10-2019, 05:20 PM   #5
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the ship's bearing is 312 by itself about 40 miles right to me. I fly on 315 bearing 40 miles east of the ship.
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Old 09-10-2019, 05:39 PM   #6
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I' m sorry the ship is travelling 90 degrees on my right hand and its bearing is 312
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Old 09-10-2019, 05:55 PM   #7
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Let me show the picture and forget all the above. I want to fire from waypoint 1 90 degrees right as you can see the Let me show the picture and forget all the above. I want to fire from waypoint 1 90 degrees right as you can see the cargo ship is travelling 013 with 11 knots. So what is the right harpoon brc?cargo ship is travelling 013 with 11 knots. So what is the right harpoon brc?
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Old 09-10-2019, 06:04 PM   #8
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I would set harpoon to 157° or 158° (directly at ship). The ship will move 1 mile during the harpoon flight, and it is heading mostly toward you.

Your plane's initial heading doesn't matter. But it is probably a good idea to face the target before shooting to reduce error.
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Old 09-10-2019, 06:27 PM   #9
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I set it at 165 and all missing, I will try at 158
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Old 09-10-2019, 07:19 PM   #10
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Just some additional advice: For clarity, always specify either "true" or "relative" bearing. This becomes critical when relaying target information to other units you are working with and who may be positioned nowhere near you.
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