OMG! What's in post 80? :o This is like a Dan Brown novel.

Exactly, that was my question as well. He refered me to a post with no answer.

This is why I suggested that he must be saying that if the bearing is 80, then the AOB is 10---at all times. That's the only possible thing he must be thinking. As I said, if he does not think this, then by all means, TELL US WHAT HE DOES MEAN.

it seems that greyrider has been long labouring under a misunderstanding of what the angles really represent.

Nonetheless, he alludes at the beginning to using the hydrophones to narrow down the possible speeds - especially if medium speed is reported, which in the game gives an upper and lower limit.

From a position of a collision course intercept, knowing the upper and lower speed limits can significantly reduce the possible range of AOB, and therefore target course.

Yeah, it does reduce the "future position arc" of the target. That said, there are still infinite straight-line paths within that arc, and only one with AOB=10 :)

Still, he seems to think all intercepts are at 90 degrees as far as I can tell. He talks about it only being useful if you are in the 8010 arrangement, but doesn't seem to realize that it is impossible to tell if ytou ARE in that arrangement until you can either visualize him, or use radar to get his course (or actually collide, and it happens to be at exactly 90 degrees, instead of the infinite other angles possible).

i think i have worked out the proportions of the triangle in 8010, so that a targets position can be known.
the ratio distance, of target distance and submarine distance to the collision point, is 5.4 to 1.
so whatever the distance the submarine has to travel to get to the collision point, the target distance is 5.4 times greater.
this will be true, no matter what range the target is at.


and the distance to the collision point for the submarine are:

5.4 in km ( kilometers )
5400 in m ( meters )
2.91 in nm ( nautical miles )
5900 in yards ( yards )
these numbers above are for a target 29.16 km or 15.74 nm away

those numbers are not a long distance for the submarine to close, in fact, it would hardly show up in the battery indicator at a low speed, the arming distance of a u.s. torpedo is 250 yards, dont forget to keep at least 250 yards between the submarine and collision point.
shoot short, medium, or long range, it doesnt matter, you will hit the target.

you might say after looking at those numbers, what if the target on an 8010
is even closer than 5905 yards, or at an unknown range.
well, the overall ratio between target and submarine distance to collision point in 8010 is 5.4 to 1, so if a target was 2000 yards away in 8010, the collision point is up ahead at
366.3 yards.

2000 / 5.4 = 370
370 x 5.4 = 2000

if target has range of 5.4 km, or 2.94 nm, then you would divide 5.4 km by 5.4, and the collision point is ahead at 1 km, for 2.94 nm it would be 1 nm ahead.


so to determine target position in a 8010, you would just have to estimate and measure the submarine distance to the collision point, draw an 80 degree bearing line to the target, from submarine center of mass, on the map,
and build the triangle.
extend a line from the collision point to where the eighty degree bearing line is, and where they intersect, thats where the target is.
this will hold true for any target speed, because any increase in target speed has to correspond with an increase in submarine speed in proportion, in order to keep the integrity of the 8010 intact.

another way is to work it backwards, draw an eighty degree bearing line from the submarine to the target on the map, the target is along that line somewhere, then with the map angle tool, draw a line over the eighty degree bearing line, extending it to the collision point, a (90) degree angle,
back to the collision point, where ever the ten degree aob line fits along that bearing line, is where the target is.
thats for an unknown range, on an unseen target, not really scientific, but it will work, you just have to play with it to find it, its not that hard,
and you can use the four numbers above as a guide, so that your in the ball park.
even so, we dont need to know or worry about target range in a right triangle, as long as our torpedoes can hit, and its within torpedo range.
i havent given you torpedo data sheets yet, and with those, you will know what bearing to fire the torpedos at, for a zero degree gyro angle hit.
the date sheets will complete the whole picture of the 8010.
there has to be math formulas for this types of measurements, but i dont know them.
you have three angles known, but not the distance between them, there has to be a formula that takes care of that.

shooting like this, with a convoy that has four ships in a row, and 3 or 4 columns, i take the first
row ,and all ships of that row get fired upon, the first ship being the farthest, then the next, then next in range, then finally, the closest one in that row, as they cross the firing bearing,
because they cross the firing bearing in that order, all get hit at zero degrees, damage and sinkings depends on where it was hit,

remember, the hydrophone listening radius is 18.35 nm, or 37182 yards, its probably maximum range for radar to, so even if you had everything known of the 8010 even at maximum range, the distance to close to the collision point is not a problem if submerged,
the submarines travel distance would be 3.39 nm, or 68882 yards.

maybe i have failed in getting it thru, for that im sorry, ill try to say it again, the torpedo fire control manual states it only has to be held constant for 2 or 3 minutes, if it said it had to be held indefinitely, it would have said so, but it doesnt, so in the eyes of the tfcm, 2 or 3 minutes of the target being held at a bearing, any bearing, is good enough for an accurate speed estimation. i put up some pics of the angles as they are seen on the sh4 editor map, didnt you see them? you could put them in paint, rotate them, measure the angles with a compass from a pencil box, and see they are. and ive done it thousands of times, only for the most part of playing this game, i never new the sizes of the angles, because i never measured them before.

joe, thanks for the imput, i was wondering where you were.
i read that story to, and i listened to those records a couple of times, thats where i heard them mention width, target width, but i never heard or read anything about a spread. my post on sealion, i said it was pretty obvious it was a radar plot, they had everything worked out by 32000 yards.
however, it says alot about risk, and zig zagging, reich took a big risk,
one near miss from yamoto, and sealion was gone, reich didnt know yamoto was there, but he knew 2 ships of battleship proportion and two of large cruiser size were there, hes a navy man, and knows the power of those guns on those bb's. and then he had to worry about destroyers,
and the sea going down the hatch short circuiting every thing, it was solid water, in a storm of wind, at night.

a spead is a lucky shot,when the solution is in doubt and that is like calling reich a lucky man that night, i like to think him better than lucky, engines straining, solid water down the hatch, gale winds, formidable enemy formation, luck could be said for sealion, but hears the thing, at present theres no proof, one way or another about that.

i guess he must of thought the risk was worth it.
dont think any of the crew complained.

i dont want to get off topic, especially since the complaints about me not being clear to you, still has you confused. remember what i said, no arm twisting here,
do as you wish, in fact, i would like you to forget it, its useless to anyone but me. i use it with success.
im not trying to get anyone to use 8010, im just showing a tactic, that i use. i now think you will never understand it. its your loss guys, not mine,
theres nothing like the feeling of tracking this way, and killing, and ill put my map skills against anyone here, but this is alot better in my opinion, but sometimes the map is needed, plotting is needed sometimes.
8010 is a simple procendure, the turn takes care of course and aob. at a certain angular arrangement speed can be taken accurately, its that simple for me, i dont know how simple it will be for you,
but i know one thing, its a matter of skill, you either have it or you dont, that simple, theres no other excuse.
When a submarine submerges, radar becomes useless and no lookouts remain on deck. The periscope and the sonar gear are now the eyes and ears of the submarine. But in the vicinity of enemy ships, it may be dangerous to use the periscope very often. Then the submarine must depend chiefly on listening. The sonar operators become the main channel of
information about the maneuvers of the enemy
The fact that the speed of sound varies, especially with temperature, explains why sound waves are bent out of their normal paths. This bending is called refraction. Usually water is warmer near its surface than at lower depths. As shown in the diagram at the right, the upper part of a sound wave in the warmer water travels faster than the lower part in the colder water.
This makes the sound wave bend downward. the bending you could say is vertical, not horizontal. sound travels in a three sixty.
on american submarines, they had whats called the magic eye.
the Magic eye indicator lets the operator's eye see what his ears hear. The eye closes when current is strongest,
on american submarines, with a magic eye, there was never any doubt about what bearing the target was on.
in this picture of the hydrophone electronics, you have two stages of amplifiers, that amplify the sound signal, its then wired to five filters, in which, one, two, 3, 4 or all five filers can be turned on separately or all at once.
these filters pass certain freguencies, and block others.
the voltage is then adjusted by a potentiometer, current is proportional to voltage, into two more amplifiers, coming out to a propeller counter, to another amplifier, to a speaker or headphones for listening.
another circuit from the output amp, goes to another potentimeter, for voltage adjustment, into another amplifier, another filter, probably to attenuate noise, to a rectifier, to drive the magic eye. this rectifier is probably
rectifing the alternating current signal, since sound is ac, into direct current or dc, to drive the magic eye indicator that would let u s sonarmen, know exactly what bearing the target was on. they didnt have to do it like i did in the movie,
because us sonar is misrepresented in the game. what i did was conpensate for not having a magic eye.
http://a.imageshack.us/img715/8823/fig16a.jpg
By null at 2010-09-04
http://www.maritime.org/fleetsub/sonar/chap4.htm

You still have not answered the question; How do you know the AOB is 10?

What you are doing is making an assumption about the AOB of the target, which then gives you a speed for that assumption. If the AOB happens to be within some small range of 10 by accident, then you'll get an estimate of speed commensurate with the difference. Pick narrow seas to hunt, and maybe you can limit their courses so that the estimate won't be crap.

Your triangle is a projection of the target's path onto an arbitrary line perpendicular to the path of the sub. In simple terms, it's a shadow.

This comes down to a bearing rate that has to be below 0.333 degrees per minute to be considered on a constant bearing. If you do the math, a target running circles around you at the edge of hydrophone range at 6.4 knots would also be considered to be on a collision course. Surely you see the error in the assumption that it is colliding, right? If it is written in the Torpedo Fire Control Manual (and it is, I read it), then it is writing BULL. (Yes, I know sacrilege :arrgh!:) ANY target will appear to be not drifting in bearing if it is sufficiently distant. At some distance the drift will not be measurable, like the 1 degree limit of the hydrophone. Yet it still moves with some speed across the line of sight. Even if it is at the point where it has 90 degrees AOB, where the bearing drift is at maximum. Even if it moves at light-speed across the line of sight. Holding onto the 3-minute constant-bearing rule you'd start to wonder when the minor-planet Pluto starts crashing onto us. It's not drifting (it takes 248 years to go around the sun), so collision is inevitable! Wrong. Long distance hides the fact that it is drifting in bearing.

If we take your 80-10(-90) triangle as given, and assume the target is detected at maximum long-range (10.8nm). And the drift stays under 1 degree in 3 minutes. It may have a speed-advantage across the line of sight (meaning over your speed*sin(80)) of 3.77 knots to still be considered constant bearing. This could be a 12 knot target that really has an AOB of 18.3 degrees if you are not moving. Or it has an AOB of 28.5 when you think you have a constant bearing and while you are moving 2 knots with 80 degrees lead. So, assuming the AOB is 10 degrees is very questionable at best. But no matter, as those will get eliminated pretty soon from the target-pool.

Why? Well, the closer the target comes, the more their bearing rate increases. So quite quickly those 3.77 knots across the line of sight will appear to be a target that is either going too fast or has to high AOB. The targets that have a smaller AOB, more akin to 10 degrees, will last longer under your presumption of a constant bearing. But eventually are evicted too

At minimum-longrange (1.62nm) the target may not have a bigger speed advantage across over yours of 0.56 knots to comply with the 3 minute constant bearing rule. This means an AOB of 2.67 degrees if you are not moving yourself. Or an AOB of 12 degrees if you think you have a constant bearing and are moving with 2 knots and 80 degrees lead. The conclusion is that only those targets that already conform to your 10 AOB rule survive until the end. Those that are not, and I'd think A LOT, get discarded before hand. Well, you allready stated in one of the earlier replies to us that many are left alone. But I really wonder how many you let go, before you find one that matches your presumptions. Please give us some (rough) statistics.

Either-way, this method turns out to be nothing but a filter for 10 AOB. You get what you want to see. Everything else gets thrown out. Don't be fooled into thinking 10 AOB is a rule.

3 minutes to determine a collision course is ok at medium range. at long range you need much longer. In the torpedo fire control manual, for this technique (which is really a pre-ww2 technique) it already assumes you have visually determined AOB, and so is most likely at medium range.

But in general the tolerance of error was much greater than is expected in this game. They made up for it with firing torpedoes in a wide spread (see above with the kongo where 6 were fired, 3 hits, by definition it was a spread covering a wider area than the target) and getting close to the target.

See also the TFCM section on early TMA based on bearing rate analysis - they estimated 2 mins was sufficient for a new solution!!

Finally, misses were more likely when radar was not employed.

Also: i don't know how often i have to say this until somebody here decides to study this further, but read the 1922 guide to the Submarine Attack Course Finder, which is designed to be used with the correct collision course technique that Greyrider has failed so far to replicate.

http://www.hnsa.org/doc/attackfinder/index.htm

I suspected that visual contact made was implied. And wondered why it wasn't explained to be bounded by that condition. Surely they must have known better. But I guess I missed it being described as part of the "Approach and Attack" phase. In this context I can agree that it is 'constant enough', but Greyrider's use of it is not warranted.

On a side note. Is there a pdf version of these manuals that do not waste so much paper space in the margins. Or does not have continuous pages. The hnsa.org layout is much to slender to print out. And I'd love to read it on paper. I know these things are for sale somewhere but I'm not that eager.

ok, where theres a will, theres a way, and i have the will,
so you ask for proof its a ten degree aob in 8010, coming right up!
im going to show you 3 pictures, of a mission, this time at 0 percent realism,
im going to make auto-tdc prove its a ten degree aob, with lead angle of 80 degrees.
the first picture is what you see if you open this mission in sh4 editor map.

http://a.imageshack.us/img521/1870/checkangles.jpg
By null at 2010-09-05


one ship is on bearing 271, another ship is on bearing 280, since this is auto tdc,]
you should be able to read the aob, on the dial in the upper right corner.
in picture number 1, the target is at 271, it has a 1 degree aob, i tried to get it on 270 for a zero degree aob, but i was alittle off.
it doesnt matter, the aob is 1 degree, plainly seen in the dial.

http://a.imageshack.us/img521/408/88099779.jpg
By null at 2010-09-05

in picture two, the target is in an 8010, it bears on 280, notice the aob in auto tdc, whats it say?
10 degree aob.

http://a.imageshack.us/img521/6550/59232177.jpg
By null at 2010-09-05

enjoy!

one more pic, this time from the merchant pov
http://a.imageshack.us/img819/5972/s...0512402583.jpg
By null at 2010-09-05

I only have one face and two palms. I never before had the feeling that wasn't enough.

Yes, you've once again shown you know the property that the three angles of a triangle add up to 180 degrees.

You have yet to prove the triangle is a right triangle, based only on knowing that one angle is 80 degrees.

The submarine is on a heading of 0 degrees. It's a right triangle only because you've set it up that way.

If the target were heading 90 degrees, as in your example, and the submarine was on a heading of 45 degrees, and the bearing to target were 80 degrees, find the AoB.

BTW, you owe me a keyboard (or a way to get coffee out of it ;) ).

Ok, please explain that to non-native american (and I do not mean 'indians') readers. I'm missing your point, ... though I probably agree.

for pisces:

http://i297.photobucket.com/albums/m...r/facepalm.jpg


greyrider:

no one is doubting you can set it up this way. the problem is the assumption that any encounter will necessarily conform to this pattern. It will not, unless you know already the true course of the target.

If you are able to eyeball the aob than that is enough, but you can't know aob in advance from this method.

part of the problem greyrider is that you are a highly experienced player with a lot of ability to visually estimate speed, range and aob, and it is my guess that you rely on visual estimates to correct errors in your theory, without appreciating you are doing so.

you can copy and paste into a word document then save as pdf and print. should only take a few minutes to remove the unwanted stuff