I like sonar work :yep:

"Visualising" the situation "atop" via passive sonar is a "must" if you approach for the kill from the "deep" rather than periscope depth. I do.

greyrider :up: for bringing up the "art"...

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Greyrider, you ought to do a video on single ship and convoy tracking by passive sonar.

Although the 8010 method as presented here seems to be a "no-go", Grayrider introduced a solid base to use the sub as a "navigation tool" to establish a target's speed and course. This is not a a "how to ..." presentation. I will only give a rough description and explain why it is doable.

The main element: Attaining a collision course.

When the sub and the target are at a (converging) collision course the bearing under which the target is observed remains constant. (Valid for constant course and speed.)

As analysed in previous posts in the this thread attaining a collision course by itself is not enough but a more "compound" approach is completely doable.

Outline of the """method""" (for a converging target):
- Attain a collision course and note target bearing (b1) and sub's speed (u1). Sub is at Target's AoB ...well AoB1 (unknown)
-Stop sub or lower its speed
-After a while start increasing speed (incrementally) until target bearing stabilises again note target bearing (b2) and sub's speed (u2).Target's AoB is AoB2 (unknown)
Note: sub has not changed course.
if the target moves at speed v (unknown) and the intercept angle between target and sub's course is w (unknown) then the following are true:

AoB1+b1+w=180° (eq. 1)
AoB2+b2+w=180° (eq. 2)

___u1_____________v
------------- = -------------- (eq. 3)
sin(AoB1)_______ sin(b1)


___u2______________ v
------------- = -------------- (eq. 4)
_sin(AoB2)_______ sin(b2)


So 4 equations, 4 unknowns the problem is solved (theoretically).
Plus the required maneuring is completely doable with fairly clear-cut criteria (stabilizing the target's bearing).

For people that have fiddled around Target Motion Analysis this may seem elementary but hey I'm an amateur :D

I remind you this "analysis" just shows that the method is doable.
BTW if u1=u2 it means that you're running parallel to the target (and that v=u1=u2).

Fire away now guys!.


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EDIT: here is a link with a diagramm for the above: link



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Salvaging 8010
 

One way of salvaging Greyrider's method is the following:

The 80/10 method implies an intercept angle of 90°.

Many players, including myself, try to "bring" the target at a 90°/270° bearing while the sub at 0 speed. In this situation you have the target's course (perpendicular to your heaging) but no clue about its speed.

After attaining the above situation go to reverse (without changing heading). After a while you can go forward (again without changing heading) and use Greyrider's method to obtain target's speed.

So 8010 with a twist (:DL) is a usable method.


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But don't you still have to track it and get it into that basic position before you dive. I'll look at the rest of the thread, but his last explanation on convoys seems to have some merit if you can get yourself into position before you dive.

My problem is once in position it's just easier using other methods, as I still like some TC, but maybe something workable here.

Yeap!
The """method""" I present is what to do after you get on a collision course with the target.
How do I get there?
Trial and error. The only thing that helps me is that if I succeed in stabilizing the targets bearing and the subs speed is "appreciable" then chances are that I'm moving parallel to the target, if my speed is low then I'm probably near a non steep collision course to the target. Plenty (x2) room of error, much more so if the target is "ziging".

Other option is doing it by the book (see link in my previous post). Sometimes I don't do the procedure correctly, but I'll tell you this, proper data collection to implement "official" methods can be time consuming (at least for me :)) as in: the target is passing in front of you while you're are drawning lines on the Maneuvering Board (had that happened too!:oops:).

Of course with radar things can get mush easier.

If you get dead ahead of the convoy, I totaly agree there are more straight forward methods to estimate the target's speed. I was just proposing a "maneuver" with which you can use grayrider's work as it is now.


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success! i just got thru playing a mission in the campaign, using 8010 on a single merchant.
i have it on film, and i will upload the film to u-tube later on tonight.
yea!!!!

well, if there is anyone that still doubts this method, i invite you to view the movie,


http://www.youtube.com/watch?v=Re7fJrQ63dA


its up on u-tube, in 8 parts, the total time is like one hour and seventeen minutes,
each part is on average 12 to 13 minutes long.
over the weekend i decided that i would have to film an engagement using this method, and prove it would work in campaign mode,
after watching the test mission work, i had no doubt it could work, but others still didnt believe it could.

in the test mission, i made, i knew all the parameters, speed, course, etc, of both target and submarine,
so i knew what speed to give both sub and target, and align a collision course for them, in order to prove the formula, and it worked!
but in a campaign, every thing is random, like real life. i didnt know target speeed or course, a random encounter as i was heading to the makasser straights
after refueling at the tender south of the philippines, figuring this method would work very well in straights, well i got my encounter in open sea,
beautiful! couldnt ask for more.
theres no narration with the movie, i will narrate it here but i may add voice later because it could really be a great tutorial.
if you watch the movie, you will probably say its looks so easy, its really not, and yet is, one thing it is is immersive, and can only be played in rt.
the target in this movie, is a single merchant, and the movie starts with the campaign loading screen, so that theres no doubt its from a campaign, and ends
with the kill, by point and shoot and 8010 combined, no maps, radar, radio reports, pk, tdc, pings, nothing! nothing but hydrophones, periscope, timepiece, and submarine knotmeter
as tools to work with.
submarine fired 3 torpedoes, with 2 explosions, one dud, all three hit, from 500 to 700 yards away. the ship doesnt look like any stock ship, so it had to have been added by ducimus.




http://a.imageshack.us/img375/9522/s...2316301000.png
By null at 2010-08-24

the engagement opens with the submarine at pd, forced down by aircraft radar contacts, i dont remember how long i have been down, but night is approaching,
its getting dark, but still there is light in the sky, the ocean is black, and the sea is alittle high.
there is a sound contact bearing 331, single merchant, medium speed, closing. the first thing the submarine does is wait, and monitors the contact for bearing change and relative movement,
once thats determined, the sub will know what way the target is going, and what way to turn, and what aob it has, whether port or starboard.
the submarine monitors bearing 320 and 321, the fringe bearings of the target for direction and bearing change, sound is heard on 321, but not on 320, if sound moves to 320, its indicating target has port aob, and will pass on the port side of the submarine.
after determining the target has port aob, submarine turns to port at 1/3, turning hard to port, monitoring sound contact with leading edge of hydrophone needle as it attempts to get the sound contact on bearing 80. sonarman using fringe bearings of the sound,
one where sound is heard, and the other where sound is not heard. the targets sound is approaching bearing 80, and submarine comes to a 15 degree port turn now, to slow the turn and get sound contact at 80, slowly, precisely.
with the target now on bearing 80 degrees, the sub straightens the rudder, and monitors for any change in bearing as it begins to adjust submarine speed higher, to search for the targets speed.
during this time adjusting speed with submarine knot meter in control room, approach is constantly asking sonarman for target bearing, and its always the same, target bearing 80.
submarine has adjusted own speed for 1.8 knots, when speed is steady, contact bearing verified at 80 degrees, and now is timed, with sonarman calling out target bearing every 15 seconds. for 1 1/2 minutes, target is held constant at 80 degrees, then begins to move off bearing eighty to bearing 81.
this movement away was not caused by bad aob or by too much submarine speed, it was caused by the submarine starting to move directly in front of the target,
but i didnt know that until later. the target was held constant for a minute and one half, so reading the submarine knotmeter at 1.8 knots, with a lead angle of 80 degrees, with a 10 degree aob, the target speed was found to be 10.3 knots, looked up in a chart from the combat information library.
3 torpedo doors where opened, torpedo depth set for 12 feet, torpedo speed set for high.
sound is then again monitored by sonarmen, checking target bearing, and target now is moving behind submarine on bearing 82, submarine lowers speed, getting ready to verify, with another search for speed, when target comes back on bearing 80. submarine adjusts submarine speed to 1.4 knots,
to let the target "catch up " to bearing 80 again, a look thru the scope, smoke! bearing 82. submarine then comes to all stop. target needs to come back on bearing 80, and target course will now provide that movement.
while the submarines waits for the target to come back on bearing 80, the approach looks up the chart in combat information library, for correct firing bearing, for a tagret making 10 knots, and that will be bearing 12, to fire, and torpedo impact with be 0 degrees.
after quite awhile, the target comes back on bearing 80, and the submarine moves out straight at 1.4 knots, it will now try to verify target speed with a second search.
at 1.4 knots, the target begins to fall back to bearing 82, submarine is slowed again to 0.8 knots, target will not come back on bearing 80, and now
i realize that its the movement on the submarine that causing the bearing change on the target, as the submarine is now moving into the path of the target, and creating a smaller aob on the target.
the submarine comes to all stop, and waits, it will go with its original accessment of target speed of 10 knots.
target has now come back on bearing eighty, solution solved as far as the submarine is concerned, target bearing eighty, 10 degree aob, course 90 r to sub, target speed 10 knots, firing bearing for 0 gyro, is 12 degrees, now its just a long wait as the target moves to bearing 12.
all periscope view now, watching target close, the approach begins to look for and see the bow wave, and approach likes it, he thinks hes in the ball park with the speed estimation.
target continues to close on the firing bearing, and its time for action, periscope is set to 12 degrees, when target begins to approach 20 degrees.
target now comes on bearing 12, and approach waits until the first mast is in line with vertical aiming wire, then begins to fire the three torpedoes.
twenty three seconds later, the first torpedo explodes, second torpedo is a dud, third torpedo explodes, target range at torpedo impact, 595 yards,
target destroyed, and 8010 is vindicated in campaign mode, where it counts. now i think im going to celebrated with a beer, and jimi hendrix playing red house!
hope you all enjoy it, if you look at it.

campaign 8010 part 2 is missing from your list on youtube.

Also, please respond to my question earlier over the testmission that you supplied. It doesn't seem to work. It's a SubmarineSchool mission but I can't get it to show in the list there. And doesn't seem like your earlier experiences when opened in the mission editor.

I see plenty of points in your narrative that I could sink your method with but I'll wait until I've seen all the parts of the movie. But it would also be a repeat of my first message in this thread.

part 2 of campaign 8010 has been reloaded up, is visible for viewing, also im sending the link for the test mission to you, its the same one that works for me,
i dont know why its not for you.

test mission http://www.filefront.com/user/greyrider
member, i m not twisting arms, :) but next time it will be with a convoy, in campaign mode. i have already chased two, that was not engageable, one was a convoy
where i had to drive on it at flank speed, and could not get close enough at night, the other was an anti submarine patrol, dd and armed trawler,had good position on them, but was detected because how
could he miss my entire length, which i was way out in front of. the other convoy had the other problem of an interfering escort at the flank, and possibly the rear guard as well, tracking last ship in column closest
the jurys still out.
:D

there are two types of closing targets, the ones you can engage, and the ones you cant, i also now consider the submarine function in the 8010 as making a search for target speed, it is searching, as much as a dd conducts a search for a submarine with active and passive sonar.

you know, i cant understand guys that want to subtract from this method, when im ready to add even more to it.
and what im going to add to this is that once you get the target on lead angle of 80, with 10 aob, you are then able to tell what the aob is for the target, no matter what bearing your looking at, just like the tdc does, as long as the target is on that bearing, also the course known at any bearing.
if after you wait until after the search for speed, the submarine stops, coasts to stop completely, and 8010 reaquired, from that point on, the course and aob can be known on any bearing.
for instance back on 8010, aob is 10 degrees, sub is not moving, target is moving , and goes to bearing 79, aob become 11, bearing 78, aob 12, all the way down to bearing 0, where aob will be 90 degrees.
the two angles of the triangle have to add up to 90 degrees, to be a right triangle, so therefore, as the lead angle decreases, the aob increases, since that happens on any change in bearing, course, bearing by bearing, blow by blow, can be determined,
the accuracy of this, is only as good as your initial 8010, or the reacquired one, sub can also be moving, and adjust tactic accordingly as needed

I figured out why the missions would not show up in the SubmarineSchool list. It seems that is is required to name the folder of the mission exactly the same as the files that are in it. You named the folder "SS09 Ten Eighty Method" but forgot to add the "SS09 " to the filename of the mission.

Now that I am able to run it, I haven't found a way to detect the target. Is it supposed to be there allready at the mission start, or do I nead to approach that starsymbol on the map. Either way I tried and found nothing.

Ditto. the method is already toast, proved that way many times in many ways by several people detailed above. The AoB of 10 has never been established, therefore the method fails. Only by infinitessimally unlikely coincidence would a random target be detected at AoB 10. If you were not at AoB 10, Then getting there from an over the horizon position would in almost all cases mean a long high speed forced surface jaunt that would blow the attack by making you obvious to the approaching target. However since you CANNOT establish AoB from the long distance, you have to idea where to make that fruitless high speed surface charge to. The best you can do is establish a collision course with the target, regardless of his AoB (which is irrelevant) and plug him by the method of your choice when he gets in eyeball range. 8010 has nothing to do with it.

What you really did was a standard visual approach with your scope hanging out of the water for 20 minutes, followed by a Dick O'Kane without using the TDC but with the speed calculated wrongly. The target was traveling slower by a knot or two from what you figured, as both hits were substantially forward of your aiming point. You were saved only by the fact that you used killer rules #1, #2 and #3: get close, no, get closer, NO! EVEN CLOSER!!!! That's the best advice ever published. 3000 yard shots have no place in a war where the object is to sink the enemy. Get close enough and a harvest of errors don't matter.

Another point making this attack method less than desirable: you are submerged, chasing your target before he ever comes over the horizon. You are running down your battery, taking your boat out of the fight and making it vulnerable to counterattack when you should be conserving your batteries on the surface. Only after visually acquiring your target should you maneuver ahead of your target and submerge in such a position that you can use minimal battery power to develop the attack. Granted, if you are extremely lucky you are only 10 degrees off his track, but at a distance of 20 miles, that is a long way to have to abuse your batteries to get close enough to shoot.

All I can say is that it's a good thing that ships don't move even remotely like they did in RL:

http://i121.photobucket.com/albums/o...ersw/ZZF-1.jpg

http://i121.photobucket.com/albums/o222/tatersw/ZZM.jpg

;)

Still not making sense to me.

Grey, help me out.

Say I am heading east and I get a sonar contact dead bearing zero, about 9NM's away heading SE away, speed 11kts.

It's obvious I have to surface, speed up and do a long end around and put the target in position for your method to have any merit. Even in your video it seems the target is in the right position. That may happen so often, but rare.

Again, if I have to do all the work to put myself in postion, by then I have all the basic info I need and no need spending all the time required by 8010, when they're much easier methods.

It's possibly a good place to start for a sonar attack in a storm once you are in position.