joe, your right again in what you say, i havent finished checking out this theory as yet, but im to tired right now to think, or even offer rebuttels, even if i had one.
but i just feel that if you keep the mathematical relations related, we should have no problem.
i mentioned hydrophone range only to make the target as far away as i could, but the range was not a factor in the speed estimation, just in the placement of the target r to sub.
it factored in the range times sin aob formula, but was not needed, i just put that there for the heck of it.
historically, you are probably right about hydrophones not being reliable at lr, some input from a real sound man might be worth its weight in gold here, but where would they be?
altho, american hydrophones, with the magic eye as it was called, was probably very accurate, i know QB was for shorter ranges, and jp for longer, whether weather
and rough seas degraded them seems likely, but i havent read much to say one way or another.
anyway im going to sleep now, tomorrow ill work some more on this, what i havent done yet is run this mission to completion, everything i did so far has been with a calculator.
i know the rock is probably busy with mobo, checking this out, and he always bring value to any discussion when he checks things out with that program, so im looking forward to what he has to say.
the one problem i have when i make these missions is that i know all the factors involved, i wish that someone could make a mission, and send it to me, so i know nothing, so that i can work it out by playing it,
i think i would give my left you know to go down to the lionfish 50 miles away and work the hydrophones on it, if they still work, and they would let me, i would love to sit and talk with someone who did in ww2

That lead formula can certainly be used to aim torpedos based on bearings only. I'm not sure it is very reliable, but that also depends on your amount of patience and 'triggerhappy-ness'.

As Joegrundman said, you must turn to maintain the target on a contant bearing. Typical intercept-course trial and error fiddling with the rudder based on hydrophone feedback. Then once stable (long enough to prove it is realy constant), the trick is to assume the target has an AOB of 90 degrees (sin AOB=1) while it is on that constant bearing, no matter what his real AOB and speed is. From this 90 AOB follows a certain (target)speed which is less than the true target speed as it it the component perpendicular to the bearing. The rest of his speed is aimed along the bearing line and is cancelled out. That perpendicular speed is all you need for leading. (well, sort of :nope: , remember gyro parallax, read further down)

The following picture illustrates it:

http://ricojansen.nl/image/intercept_angles2.JPG

So:

perpendicular speed= sb_speed*sin(lead_angle)/sin AOB

which is actually =sb_speed*sin(lead_angle) , since sin(90)=1

This 'perpendicular' speed is the same for you, trying to keep up with the target, as it is for a torpedo, that tries to merge with it.

If you can enter that speed and AOB 90 (referenced to that particular bearing) in the TDC you have allmost everything done. You only need a range to account for gyroangle parallax. Or you can turn towards the target (quickly, so not to invallidate the constant bearing) just before shooting to make the gyro angle 0.

But the inaccuracy will be in how long you give it time to prove the bearing drift is really zero. And given that bearings are reported per degree. A slow drift might take tens of minutes to show with long range targets. Drift means there is a difference between your perpendicular speed and his perpendicular speed. Because of this difference the torpedo lead will be off and so can be passing in front of the bow, or behind the stern. Depending on range, since distant targets are small angular-wise. The nearer the better chance of a hit.

One caveat: A target that in reality is moving away will 'appear' to have the same perpendicular speed. The only way you can distinguish is the sonar opperator telling you it has a changed range qualification, or if the sound becomes weaker in the earphones.

i was thinking about what i wrote here, and i may have been off one degree with my target AOB measurement. im thinking that the constant should be 10°, and not 11°,
as i said , i measured the target aob using a gta 5-2-12 coordinate scale and protractor, its clear plastic, and has a piece of thread in the center of it that extends beyong its
edges, and used to bearings, azimuths, in mils and degrees. well to get the thread to stay you have to tie one end in a knot, and so when using it to plot on maps, you have to place
the center of the protractor over your sub, sometimes the knot is alittle to big, and the editor doesnt help at long ranges, i did the best i could to be as accurate as possible, but i think it should be
10°.
when i made the mission, i set the targets course for 90°, so if you follow the aob trainers advice, 280-180=100.
because the targets aob is starboard, you subtract aob from the difference of 280-180.
if thats the case, then subtracting 11° from 100°, would give the target course 89°, but i set it for 90°.
so belay that on 11°, the aob for the target constant should be 10°

One caveat: A target that in reality is moving away will 'appear' to have the same perpendicular speed. The only way you can distinguish is the sonar opperator telling you it has a changed range qualification, or if the sound becomes weaker in the earphones.


or, you could tell by trying to keep a bearing constant that just wont stay constant:salute:

pisces, il havent got time now to think about your post rite now, but i will certainly sit down with it soon, thanks

Nope, targets moving away (AOB >90) can also be made to be at a constant bearing. AOB X appears just the same as AOB (180-X) if you depend on bearings alone. (remember: sin(53)=sin(127) ) Infact the target would appear to be at a constant bearing more easily as the range increases, which slows the drift down as time progresses. The perpendicular speed isn't smaller or bigger, or changes in an unstable way (which is what "wont stay constant" implies), it's just divided by an ever increasing range to result in a slower angular rate.

EDIT: if you cannot get a constant bearing at all, then either you are too slow (his perpendicular speed is bigger than your top-speed), or you have not turned your speed to it's best use which is really when the target is on 90 or 270 degrees bearing. But a target moving away is then out of the question.

If those two aren't the case, the only reason left is you have a traitor on board telling the target what you are doing.

yes, your right, im wrong, sometimes i dont know what im thinking, but the key word in all this was closing. targets like you mentioned and targets going away are another ball game, you either persue, or leave alone,
thats a command decision. i really appreciate you and everyone who supported this thread with thier own knowledge.
believe me, after i posted this, i was sweating bullets, thinking that someone would find a flaw in this, but no one has posted saying anything like," grey, nice try, but it just wont work"
thats what i have been waiting for, someone to prove the theory wrong.
i have alot on my mind at the moment, im not employed now, my former boss is a little greedy piece of crap, and i stuffed it to him, nobody practices economic terrorism on me, and i decided i will not work for anybody again.
so now i have to find a way to bring in an income.
i have always loved greyhound racing, and im pretty good at it, or at least i was, i havent really applied myself to it in quite a while, but ill be damned if im going to be blackmailed by some freaking employer,
my favorite track is gulf greyhound park in texas, i have an account with paydog, and i can bet, "invest" by simucast, im going to be spending alot of time looking over racing programs, because i need to make a living and pay my mortgage and other bills,
including property taxes that i just hate.
i know one thing, my former boss regrets what he did, and asked another technician i worked with to talk to me about coming back, i refused. if i can make my living thru racing, then the checkmate is complete, and i can laugh.
one thing im not going to allow, im not going to be defeated, so ill have to concentrate mostly on this, ill post things here about the game when i can, because thats always pleasure.
all i can say to you guys is thanks for your support in this thread, at least none of you guys have called me a bonehead here.

No worries, me too, more often than I'd like to admit. Sounds like you had enough on your mind to allow yourselve to make a bit of an error.

While I would be the first to advocate a profession you actually enjoy doing, common sense tels me something that involves race-betting might not be a smart thing to do. But maybe I misunderstood what you actually have in mind. Anyway, it would be going off-topic. Best wishes for whatever you do.

I think, greyrider, nice try. it works almost as you envisaged, but not exactly. Nonetheless, i think this is a valid, important, historical and effective technique for getting speed that you have hit upon, and works particularly well when you have the skill of visual aob recognition - which you do. In fact the two techniques are matched for each other.

So all you have to do is set up a constant bearing collision course, and once the target is in visual range, take one aob and range estimate and then you have all the information you need with a single periscope view using the formula you have(best at medium range *)

This seems to me a very authentic way of doing it without hundreds of periscope views. Just one is enough - with the aob and range you can work out the course you need to maneuver for attack position and then just need one more scope view before firing

the whole thing can be done in this technique with just two scope views - which is i think you can agree - a very satisfactorily authentic attack style.

I suppose once you've done this you could make a new trainer demonstrating an entire attack this way and attach it to your aob trainer thread

* if you use follow contact only, you don't get a range approximation, but if you regularly hit report nearest sonar contact, once if it's between around 4000 and 2000m it is reported as medium range (i don't know the exact ranges)

Finally, i hear that the best way to make a living in the gambling business is to be on the selling side, rather than the buying side. You could get involved in dog training or race organising for example.

Here's a step-by-step example

So you have a long range sonar contact

Phase 1: set up collision course

Step 1. point your submarine at the contact
Step 2. Observe if target is going to pass your port or starboard(ie the bearing to target moves from 000 to 359, or if bearing to target moves to 001)
Step 3. if target will pass to port, turn about 80 degrees port. If target will pass to starboard, turn about 80 degrees starboard
Step 4. Adjust speed so that over a 5 minute period the bearing to target doesn't change, and are thus on a collision course

Phase 2: get the data

let's say after 30 minutes of staying on this collision course at 3 knots the report sonar contact says that range is now medium. The bearing to target has not changed in all this time

Step 1. Up scope ID target, note aob and range, down scope
Step 2. Use the formula (or an iswas if you have one) Let's say the bearing(lead angle) is 90 and the AOB is 30 and the range is 5000 m.

The formula:

ts=ss x (sin LA / sin AOB )

ts = target speed
ss = submarine speed
LA = angle from the bow of the submarine to the bearing of the target
AOB = target AOB.


ts = subs speed(3knots) x sin lead angle(sine 90 = 1)/ sin AOB(sin30 = 0.5)
ts = 3 x (1/.5) = 3 x 2 = 6 knots.

Step 3: plan attack course. Having worked out range and aob you can use the map tools to draw the target course (or an iswas or sacf if you made one) and range and work out the angle you want to be on for an optimal shot and at what range you want to be when you fire.

Step 4. adopt new course

step 5. when target reported to be approaching the firing point, up scope, recheck aob and bearing/range, and fire the fish

well, joe, i was the author of the point and shoot technique, the method that doesnt need to know target course, range, or aob, all it needs to do is get a closing target on an 80 degree offset,
what the TFCM calls lead angle, and a speed estimation, which i always did by scope in sh4.

i knew nothing of this formula when i made it. i wasnt satisfied with getting target speed by ship length with the scope, and turn counts in sh4 are practically useless.

so i tried this formula. the way i set this mission up to test it was what would happen after you turn
the submarine to get the lead angle on the target, (80° offset) on a closing target.
even tho i have not run this mission, i already know the end result, the target will be destroyed, because it is the point and shoot technique,
with just a different way to get a targets speed, without putting your scope up, that was my objective, and it is done,

no one can prove this not to work, because this was the way i have always gone about sinking ships,
its just another way of getting target speed.

for me, it needs no more external analysis to work, but i wont stop anyone from putting thier own ideas up, and trying out something different, to each thier own, but ill tell ya, military people are just ordinary folk,
with ordinary intelligence, the best ideas and the best tactics are the ones that are kept simple.

i have done alot of work on alot of different things, i have exploited almost, well everything we have for sensors, in keeping with the inspiration i got from the u-boat commanders handbook.

the actual history of the point and shoot technigue goes back to sh2, when i commanded that great wolfpack seetufel, with jim and yvonne hill, peter wolf, and myself. it was in sh2 that we learned how to fire underwater at 26 meters, and get hits
against first fleet, the bearing speed charts were made while seetufel was still in existance, we never practiced it tho, but it was invented by then, i just carried over that work on my own after sh2.

those where good days playing against people like iron reaper, microdot, oneger, sword, kalloth, von spike, stdev and others. i have fond memories of all those people, it was also the cause of the first great flame war in the wpl,
and that was a real shame, because it broke up seetufel, and some of the key members of the first fleet.

i guess what im trying to say is that of all the things and tactics i worked on, the formula presented in this thread has been the most exciting thing for me that i did since learning to shoot underwater with seetufel.

im not playing the career in sh4 any more, im waiting for sh5 now, and i wish so much for a destroyer command 2, because i would love to work on destroyer tactics. everyone in seetufel had destroyer command too.

and one of the reasons why i share all the tactics i make here is because seetufel was called cheaters, which was not true, and if all my work is examined by the members here, everyone can plainly see that no cheating takes place,

i did that to vindicate seetufel, because seetufel did what any military organisation does, we were silent about our tactics until it had reached the breaking point, then we told the members in the wpl what we were doing,
it didnt do any good by then, bad blood had taken hold.

for me, im done here in this thread, when i can, ill look again at the TFCM, if i think theres more we can gain from it, ill work on it. of all the things i work on, this thread is what im most proud of, and the funny thing about it is i dont know where it came from.

again thanks joe, and all the members who contributed.