Intercepting targets

[Egon01]

Hi

I have long break from SH and now from few weeks I try to learn almost everything from beggining. I did many tutorials and I do not have problems with manual TDC and etc. I use patroling method which I found on this forum (I draw 18km circles and move to centers of this circles, submerge and listen with my hydrophone), this method is very good, I found many contacts using this but problems comes when I find the contact. I can't find intercept course to him, I know only bearing (don't know distance, so I can't find his true course). How do you behave in this situation? What should I do? I did tutorial with finding out intercept course but in this tutorial I know enemy ship course and speed...

Please help

Thank you

[gAiNiAc]

When you first find the contact estimate his range and then mark him on that bearing. Continue observing the target for a few more minutes (10 is good) then range and mark the next bearing.

Draw a straight line through the marks on your map and you now have the targets course. Next just plot your intercept.

[Egon01]

Problem is that I don't know how to find range to him. I know I can do this using hydrophone but this thing shows difrent ranges every time I ping.

[Zero Niner]

What I do is to use the tip of the sonar contact line as a proxy for the ship's location. Get at least 2 (preferably more) plots and do a "best fit" line. You'll then have a rough indication of the ship's course.
Plot an intercept, then after a while (say 15 min or 30 min later, it all depends on the current situation) repeat the process to refine the solution.

Note that sometimes the ship changes course, and that will throw off your solution and you'll have to start all over again.

[gAiNiAc]

Originally Posted by Egon01

Problem is that I don't know how to find range to him. I know I can do this using hydrophone but this thing shows difrent ranges every time I ping.

Learn how to use the stadimeter........

Practice makes perfect..............

[Pisces]

This technique is what you are looking for:

http://www.subsim.com/radioroom/show...mittelwaechter

The rapidshare link (to a self-playing video) in the final message (mine) is still alive.

Or, using the following tool described in this message (no, I'm not self-promoting for vanity reasons) gets you the target course only. (which is basically the same as halfway in the video upto the point he starts moving his sub, just a different graphical way) No range or speed is given with this! That needs to be figured out from succesive bearings taken from different positions.

[Rockin Robbins]

Using sonar to find targets is slow, has too low a range and sets you up for the range problem. It also keeps you from finding targets because you have to take all that time to submerge, listen, locate targets and if you use Pisces' method, triangulating them.

Much better to join the twentieth century and realize that your boat is far superior to the U-Boat you are imitating. You have radar. Stay on the surface at cruising speeds, set radar for max distance and cover 100 times more water than the sonar technique. Radar has much better resolution than sonar, will even show your the exact disposition of ships in a convoy and is the gold standard for finding range. What's not to like?

Don't misuse your tools. Just because sonar conceivably can be used to find targets doesn't mean it should be used that way. It's a slam dunk. The number of targets you find is proportional to the number of square miles of ocean surface you can search. Underwater sonar search is so slow, it isn't even worth consideration as a search technique.

[Arclight]

But what if he hasn't got surface radar yet, like me? Or the target is beyond visual range, ruling out the stadimeter? I'll just go ahead and give you a method I use and find very simple;

No use in pinging on long ranges, the dial on the sonar station only goes to 5000 yards. You'll still get a return if you wait long enough, but the limit on the dial might be an indication that it's not ment for those ditances. Requesting a range from your sonar guy is wildly inaccurate (in fact, I find he only gets it right when you already made a reasonable entry yourself).

Like mentioned above, have a look at the map and place marks on the end of the sonar bearing line every minute or so (You can also use the distance between these marks to calculate his speed ). If you observe for ten minutes, you'll have ten marks, in a more or less straight line.
Take out a protractor and click some distance away from your marks (be zoomed in as far as you can while still seeing all marks), place the second point on or near your first mark and draw the leg along your marks. Note the angle indicated and zoom out so you can also see your boat on the map allowing you to plot an intercept. Now extend the leg of the protractor running along the marks while keeping the angle the same.
Take a ruler, place the start on your targets last known position and measure off along the extended leg.
Take out another ruler, place the start on your boat and have it cross the extended leg. Now try to get the distances to match up on the crossing point (the further you zoom in, the more marks will apper on the ruler lines); if the distance from your boat to that point is the same as the distance from your target to that point, it would take the both of you the same amount of time at the same speed to get there. By travelling faster then your target you should get there first. You could also head for a position a couple of miles further along your targets course to make sure you get there first and stay outside visual range while doing it.

I also use this method, which is slightly more complex but probably more accurate:
http://www.subsim.com/radioroom/showthread.php?t=88961

If you find yourself behind your target and playing catchup, estimate his course and steer a course paralel to his while staying outside visual range. When your at an AOB of 45deg. (bearing 135 or 225), turn in 90deg. and move in to intercept his course.

Probably overdid it since you only needed a range, but I prefer to paint the whole picture. Makes it a whole lot clearer. Hope it helpes.

[Egon01]

I just started the game so I do not have radar yet. I wrote I know how to behave and what do if I have visual contact with target. I wrote I have problems with estimate course of target when I do not see him only hear him...

Thanks for tips, I will have to practice more and will read all links you gave me with tutorials how to do it.


Arclight - for sure I will practice your method. Link which you gave is great too but I play on full realism so I do not have "map contacts" which could make it easier.

(sorry for my english, it's not my first language).

[XLjedi]

If you're playing at 100% realism, with no hydro lines on the nav map, no sonar, no radar, you could take on the job of the tracking party and actually do the target motion analysis (TMA) with hydro bearings alone. I have a gadget that I use for that...

[Rockin Robbins]

Originally Posted by aaronblood

If you're playing at 100% realism, with no hydro lines on the nav map, no sonar, no radar, you could take on the job of the tracking party and actually do the target motion analysis (TMA) with hydro bearings alone. I have a gadget that I use for that...

If all you have is sound bearings, analysis can put you on a course where the bearing no longer changes. Once that is achieved, you are on a collision course. The real submariners had a bearing rate analysis graph that they used for that.

The goal is only to find a course where the bearing no longer changes. Then continue until you hear a crash!

You might not know about aaronblood's tools. They are first rate!

[Egon01]

Can anyone make tutorial for this please ? I found one, very good video tutorial in tutorials section how intercept targets using only hydrophones (for example when there is very bad weather). The problem is that in this tutorial the ship is close to sub about 5 km and find range to him using hydrophones is not dificulte. Rest of tutorials using 100% realism describe situation when target is close to you and using hydro range makes sense but non of them describe the start phase of intercepting :/

[quote=Rockin Robbins] You have radar. Stay on the surface at cruising speeds, set radar for max distance and cover 100 times more water than the sonar technique. Radar has much better resolution than sonar, will even show your the exact disposition of ships in a convoy and is the gold standard for finding range. What's not to like?

going after a hapless merchant is one thing but convoys or task forces?
So, you don't care that the destroyers/warships know you are there? What about the element of suprise? On a related note, do you ping convoys? I'm just asking. personally, I love your videos and have learned a great deal from them. How about one on task forces?

[Pisces]

Sure, if you have radar, USE it. Those stupid Japs don't have anyhting meaning full against it. But as has been said, you don't get one at the start of the war. Or it might be damaged for whatever reason, and that is not really a patrol-aborter IMHO.

Originally Posted by Egon01

Can anyone make tutorial for this please ?

You did notice I mentioned a video, didn't you? I know it's done with/for SH3, but it ain't any different on the far side of the world. All you need is some bearings to do it. Well, and a bit of practice drawing the stuff. (The movie-file might look a bit scary as it is not a regular format, but is actually a working application. There's nothing to worry about though. Rely on your virus scanner if you feel unsave.)

[Ducimus]

>>I know enemy ship course and speed..


In TM, that speed to distance chart attached to the gramophone is VERY handy.