point and shoot possible?

[greyrider]

17.6% error? maximum?
i'd say that was a pretty good, i would take an error risk that small, anytime.
thanks rock, that was good to know. even if its overstated, thats still acceptable, for me anyway.
your very welcome, and if you organize an attack thread, you can use anything from me anytime bud.
you sank that ship, huh?
i could tell, certain words you said.


i have made contact with a convoy in the campaign, still far away, and i saved the game, so i could play the convoy attack tonight, using this technique,
take pics, and post the attack, i got the full version of FRAPS, today, i may try to make it as a movie, but i dont know how good i will do,
i have the soundtrack of the good, the bad, and the ugly, sorta goes with submarine warfare, i like to play certain parts of it, from the gramaphone,
dont know if a copyrite issue is involved either, but i might try it, just to see if it would all work together, and if my voice could be added.
i dont know if these things can be done, but i know the technique can be done, so maybe ill just stick with pics, especially since you, and maybe some
other guys understood it, just from the pics.
it might be a couple of days until the convoy post shows up, but i think you will like the carnage

[Rockin Robbins]

Originally Posted by greyrider

17.6% error? maximum?
i'd say that was a pretty good, i would take an error risk that small, anytime.
thanks rock, that was good to know. even if its overstated, thats still acceptable, for me anyway.

It's better than that. I believe when I run the numbers I'll find the error is more on the range of 2 or 3%, not 17.6%! And if I'm right in my head here without checking, any angle close to a right angle, up to plus or minus 15º should be plenty accurate. That's 30º of pure slop to play with, with impunity! Stay tuned for more info and I'll most likely draw it up so you can see that it's correct just by inspection. Fancy math is just fine, but it's only a subsitute for a nice simple, elegent diagram that anybody can understand.

[Rockin Robbins]

Sorry about the delay but I wanted to see if I could a: convince myself I was right and b: be able to explain this puppy so you might agree.:hmm: As usual I pulled out MoBo and drew out the situation to check calculations. Here's the deal in math: The error in percentage of angular lead is close to 1 minus the cosine of the angle of error. Well that's clear as mud! And I'm sure you dragged your trig tables out to sea with you and want to consult them during the attack. So let's draw out a couple of cases and see how much error we can tolerate. Once we figure out that, we'll just throw the trig book out the window and over-generalize the situation so we are just left with a rule of thumb to follow and don't have to bother with it again.

MoBo time! Thank you aaronblood for a great program.

Here we have 3 courses, slightly different from each other. The middle course is a boat on a perfect right angle course to us between two parallel lines a certain unimportant distance apart. In this case, the target travels 3642 yards between them at on a 90º track. But what if it really isn't on a perfect right angle, if it were off, say 10º, how much difference would that make? All we have to do is draw the two 10º error courses, 100º and 80º, which you see in their reciprocal couses, 280º and 260º. Then we can measure their lengths, 3699 yards. They are 57 yards more distant, 57/3642 tells us it will take 1.56% off their apparent speed from one end to the other. That corresponds to a 1.56% lag. Our chart of a 7 knot target on a right angle course tells us to lead the target by 7.5º (Mark 14 high speed). Our error is 1.56% of that, an immeasurable error. So you have an absolutely free 20º of slop there! You "might" see an obtuse angle? Might not be important!

Next example Fred. Hey, keep it down back there! Put that comic book away, now!

Yeah, 10º either way might be a little tight. What happens when we open that up to 15%. Mobo, that's your cue:

Yup, we've opened up the error cone to plus or minus 15º, that's a big 30º of error. Seems real consequential to me. Let's do the math here. The perfect right angle course is still 3642 yards long. The two error courses are the same length: 3772 yards. That's a 130 yard difference, a 3.6% error. 7.5º lead angle *3.6% error means an aiming difference of .27º on a scale you're lucky to be able to set to the nearest half degree!

Regardless of the distance of our course, the ratios will be unchanged. I only picked fairly large numbers so our measurements would have the desired accuracy. Make sense? Anybody have any different ideas?

I'm going to say this proves that greyrider's technique meets the #1 requirement of any tactic that can be successful in battle: error tolerance. It still has to work when everything goes to..... you get the idea. If you can't judge a right angle with 30º of available consequence-free slop factor, find another method that makes more sense! I say this is plenty good enough for me.

[greyrider]

wow,

rock, you da man, that was some great figuring you did, i dont know if i understand it all yet, i read it , and now i will be leaving for work soon, and ill think about what you demonstrated. when i come home, ill read it again.

but that explains alot as to why there is hardly a miss, and i know i have shot at ships with obstruse angles and have hit them.

if anything, david sandbergs program "intercalc", which was the program i used to figure out this technique, was the driving force behind it, if not for him and his program, this technique might not have been done by me.

so many members, have done alot for the community, its really great, the generosity of the community is remarkable, lots of people helping people.

thanks rock, for that explanation, ill read again when i get home, and absorb more
of it.

i had to blow off that convoy, that i said i encountered, it was a reported convoy,
i think those convoys are to easy, to use the technique on, i have been driving around in the same general area now, looking for an chance contact with an unreported convoy, to demonstrate the convoy attack, i have to go out tonight, and may not get the chance to play it, but eventually , by the weekend, i should have played, and will post.

[don1reed]

Great post, RR & gr!

[XLjedi]

Originally Posted by greyrider

if anything, david sandbergs program "intercalc", which was the program i used to figure out this technique, was the driving force behind it, if not for him and his program, this technique might not have been done by me.

What does "intercalc" do?

Is it something I should bother to look at? :hmm:

[greyrider]

arron,

intercalc is a torpedo solution program.

it variables are torpedo speed, target speed, target bearing, own ship speed, target course, own ship course, and time to impact.

real nice, and i think you should take a look, as your mobo program is also a very good program. it used to be on subsim, for a d/l, but i could'nt find it, so i posted
it at this link, if you want to d/l it, its there for you., you might find it something you want to work with. i used it because i wanted to find just solutions just for 0 gyro angle on torpedoes. but you could do the same thing for every beariing on the 360, but you would have a mountain of data, i just stuck with 0 gyro angles.

anyway, this is the link to get david sandberg's intercalc:

http://hosted.filefront.com/greyrider/

[greyrider]

rock,

i understand it now, thanks

yup, since using this exclusively, since the earliest days of sh3, i just cant shoot any other way, the tdc and stadimeter are just to unresponsive , things can change rapidly, on the battlefield, and this technique, is about the fastest way to respond to changing conditions that i have found.

i hope that you use it as your own now, it belongs to the community now.

lots of guys around here that are tactically minded, you, arron, don, love reading your posts.

[XLjedi]

Originally Posted by greyrider

arron,

intercalc is a torpedo solution program.

it variables are torpedo speed, target speed, target bearing, own ship speed, target course, own ship course, and time to impact.

anyway, this is the link to get david sandberg's intercalc:

http://hosted.filefront.com/greyrider/

Ah... I see. Thanks for the link.

The intercept tool in MoBo is a little more interactive than that one. I like moving stuff around and watching the solutions change dynamically.

But it does give me an idea... Hmmm... :hmm:

[Rockin Robbins]

OK, check out this, where I reduced it to the number of yards the aiming point is off. It depends on knowing that for something to have an angular size of 1º it has to be approx 53 times further away than its length. This derives from the definition of a cotangent. So we know if something is really 1" wide and it is 1º wide with our periscope, it is 53 inches away. Cool, huh? MoBo time! I'll learn this thing yet.


It's just another way to look at the problem, figuring out how far off our aiming point is in yards. At over a mile distance, we're 13 yards off at a 15º error. Not too shabby!

Proviso: aaronblood says the error is about 2º, or in our scenario here (3642/85)*2 = 85.7 yards error at 2271 yards range. You know what? With a nice size ship at 300 yd long, whoever's right you just hit it! If you fired a nice 3 torpedo 1º spread you just sunk it from a mile away! From 700 yards this is devastating. Let the carnage begin!

Edit: Both MoBo and Intercalc, which share the same characteristic of rounding to the nearest degree, show that my prediction of an error of a fraction of a degree is correct with a 15º error in couse from a perfect right angle. Shoot with confidence that your speed measurements are critical, your angular measurements a lot less so long as actual angles are within plus or minus 15º of your estimate. Outside of that, your aim deviates quickly!

[XLjedi]

I took a slightly different approach to the plotting when I was lookin at this stuff a little while ago...

I was playin around with trying to develop an optimum spread angle for a 3 fish salvo. Looking for the spread that would give me the best chance for at least 1 hit in the 1000m to 1500m range. I settled in on 2°.

Few observations came out of it...

1) I realized the AoB had more of a margin for error than speed. So I sorta adopted the position of "Speed is the Key".

2) The error margin for AoB was not symmetrical. I had more room to be wrong in overestimating rather than underestimating the AoB. Which plays right into our natural tendency anyway, so that was nice... (see M1)

3) I could be off by 1 knot and still score a hit if my AoB estimate is good (see M2)

4) ...and then I noticed I could expand the margin for error on AoB by purposefully underestimating the target speed. That sorta caught me off guard. I tell the TDC the target is moving 7kts when I know it's 8kts and I pick up an extra 20° of fluff in the AoB estimate... and might still score a hit, go figure. (see M3)



I have to keep in mind though that as the AoB error increases the cross section of the ship decreases and it becomes an odd angle so I'd need pistols set for mag-det. We like to hope we're not off that much in our estimates right?

[greyrider]

well, after reading the rock's, and aaron's posts, showing these examples in the program MOBO,
i'm just going to have to d/l it. i was so interested in this program when it first started to appear
in threads, but arron was still working on it, and i lost track of it.
but im going to get it now, really nice program aaron!

last nite i did play for a bit, and i got a radio contact, task force, warship convoy, there are 3 carriers,
battleships, cruisers ,couple of merchants, and plenty of dd's.
the thing about this task force, is that its zig-zagging, its about 7km away at the moment, i saved it.
its making very deep zig-zags, shooting flares in the sky, its hunting for something, i think this is the very first time i have ever seen a zig zagging convoy.
this is going to be a real test of the technique, against a zig zagging task force, at the moment my scope is pointing at 280, and they are closing.
they zig and zag from a base course of 237 degrees, im going to try to get one of the carriers, using the technigue.
i think im just going to let fraps run, as the ships close, then post it if im sucessful it taking the carrier down.

[greyrider]

scratch one carrier!
imageshack is not working this morning, so ill post pics later. the carrier was hit by four torpedoes, using the technique.
i guess this really says that the technigue can work, under any circumstances.
i found out by attacking this zig zagging taskforce however, that targets changing course constantly, was what the position keeper was made for.
it probably would have been easier to attack, THIS TIME, using the PK. reasons being my scope was exposed alot, they were already in a defensive posture,
and looking for someone, my scope had to be very low, and i took pics i had to throw away, because all they were showing was waves in the way.
my main consideration was not being detected, as they got closer, there were ships all over my 360 when it came time to fire, and i did get
my forward section pushed down to 69 ft, by an enemy ship running over it, causing no damage tho. i cant believe my luck with the examples i have been posting,
one was a turn and stop, another involved maneuver, and this one zig zagged, theres only one more, a normal merchant convoy on a straight track.
ill post the rest later.

[greyrider]

situation: s-38

patrolling luzon straights, the submarine received a contact report, large warship taskforce,
heading southwest, approximately 14 nm ene from s-38's current position. s-38 decided to take a look,
she was looking for unreported merchant convoys, but could not resist getting a look at the taskforce, in case there may be carriers.
the targets course was projected on the map, the enemy formation on course 237 degrees. s-38 proceeded to its CPA to the taskforce, then to PD at allstop,
to listen for the enemy approach.
sonar reports multiple warship screws,closing, medium speed. the contact report claimed the taskforce was making 11 knots for speed.
tracking by sound, the amplitude of the screws increasing, s-38 held her position, until visual sighting of taskforce in the direction of 280 R.

looking thru the scope at the approaching taskforce, the ships were zig-zagging, and i saw at least one flare go up. they were in a defensive posture.
i counted 3 carriers, and battleships,heavy and light cruisers and destroyers were screening for the carriers.
during a zig, a carrier at long range turned, and completely presented the whole starboard side of the ship to the submarine, and we took that time to calculate
the speed of the taskforce.

calculating the ships length passing the aiming wire of the scope, we calculated 37 seconds, it was fairly easy to id the carrier, because of the crane at the stern, and multiple
masts aft of midships, she was a hiryu fleet carrier. her speed, 11.6 knots, we dropped the .6, and determined the taskforce was still doing the reported speed of 11 knots.


s-38 opened all tubes, torpedoes set for 15 ft, leveled the boat at 48 ft, and put the rudder straight, lying motionless, the submarine rigged for silent running,
and rigged for depth charge.

raising the scope, we looked for the nearest threat, using high power, a destroyer, still at long range, but closing on the submarines position in a zag.

the rest of the taskforce was also in a zag, there coming! down scope.

the taskforce closing, we switched to low power on the scope, and continued to watch our closest threat, while at the same time we watched the course,
s-38 was prepared to move in any direction, if we had to, to engage any target that came close to us, because the ships advance was unpredictable, the primary target,
the fleet carrier, could zig zag either in front, or to the rear of the submarine, we had to be ready to move against it in any direction, or to forget about it,and take on any target
that was nearing our position.

[greyrider]

raising the scope again, we focused on the target, the carrier, she had zigged right onto my 280 bearing, with a starboard AOB, the triangle is set.

turning the scope in the direction of the leading escort, and closest ship to the submarine, we watched nervously as the destroyer passed the point of torpedo impact,
the destroyer was in a perfect 90 degree course to the submarine.

the carriers are closing, all three are in the sight picute of the scope, still zig zagging, two near bearing 288, and the third bow spray seen near the left
of the scope. still anybody's guess as to where the cv's will go, s-38 continues to hold its position.

the primary target is the more distant ship in the next picture, but between the target and the submarine, came another carrier to close to shoot at,
and masking and blocking the view of the primary target.

the carrier passing to the front, not more than 250 yards, we brought the scope low, to avoid detection, surface engine noises all around us now, we have looked to our blindspots
frequently, trying to avoid collisions.
after the big carrier crossed our line of sight, we were able to pick up our target again, just before it approached the firing bearing of 343 degrees, we also picked up a ship approaching
us on a collision course, and we put the submarine to reverse, back 2/3's, to avoid the collision, and began the firing sequence, once the target was on bearing 343.


still backing up to avoid the collision, the first torpedo hits the carrier, as the bow of an enemy ship, collides with the forward section of s-38, pushing
her down to 69 ft, but not causing any damage, accept to the deck gun that had been damaged earlier in an air attack.

all four torpedoes have hit the carrier.

the enemy carrier was destroyed and sank at 18:11.

clearing the ship that collided with us, s-38 went to flank, and crashed dived, and settled at a depth of 260 feet, on the way down, she was attacked, approximately 6 depth charges came close,
no damage, and she turned to the back azimuth of the convoy, until we had put distance between us and any attacking destroyer.
at 18:27, not hearing any destroyer approch us for quite sometime, s-38 came to all stop, and secured from silent running.