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]

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/showthread.php?t=110619&highlight=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 (http://www.subsim.com/radioroom/showpost.php?p=875260&postcount=10) (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... :yep:

[Rockin Robbins]

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... :yep:
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 :/

[Urge]

[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.

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.

[Egon01]

Sorry Pisces, I lost this line of your post:

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

:smug:

[buddha95]

im not as smart as others,, but this works for me. i close on the surface till i see them on my map,, i ignore the dd's cause they are eratic, i put an x on large ships and merchants, then submerge. in 5 mins i look again, draw a line from start to fin and i have a course, then i end around and (hopefully) get some.

[Egon01]

Pisces - I downloaded the video with tutorial. This is what I was looking for. Excellent video. Thank you :D

[Pisces]

Pisces - I downloaded the video with tutorial. This is what I was looking for. Excellent video. Thank you :D:up: But I'm just the messenger so to speak, MittelWaechter deserves all the credits for it.

[Egon01]

So thank you MittelWaechter for great video ;)

Well I allready sunk few ships using method used in this video but I have technical question about sonarman. From time to time when I accelerate time sonarman lose the contact, even when I tell him follow it. I mean after 9 min. when I ask him for new contact report he says "No sound contact". I have to spot target with hydro manualy again. Is it game bug ? I know my crew AI is not superb but is there any solution for this issue ?

[Pisces]

It's the same thing in Sh3, you just have to live with him being a nitwit. Maybe he improves as he get's experience. But there's nothing you can do.

[Rockin Robbins]

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?
Every once in awhile, someone asks me a GREAT question. This is one. Joe Enright in his book "Shinano!" says that he kept his radar on while stalking Shinano even though the Japanese definitely could detect his radar signals. Here's why.

The Japanese knew somebody out there was emitting radio signals at American radar frequencies. But Enright knew the exact speed, course and disposition of the enemy. As long as the radar gave him more information than it gave the Japanese and he was not in immediate danger as a result of detection, he left it on.

I feel the same way. If I see a destroyer come in my direction who could not have seen me, I might turn it off for ten minutes in July 1944 or after. But then it goes right back on and stays that way. Remember, they don't see what you see. The most they can get is a bearing, and that will be nowhere near as accurate as what the radar tells you about them.

[joegrundman]

ESM is one thing, but why can't they also see you on their active radar?

[Arclight]

The Japanese underestimated the importance of (specialized) radar, and as such were slow to incorporate them into their navy;

http://www.star-games.com/exhibits/japaneseradar/japaneseradar.html

Scroll to the bottom to the conclusions for a quick (and more detailed) answer. ;)

[Egon01]

I have one more question about this video tutorial. What if I spot target for example on bearing 300 ? Do I have to change my direction to target to have it on bearing less than 180 ? It's importent coz as you all know ;) protactor shows only 180 degrees..

[Rockin Robbins]

ESM is one thing, but why can't they also see you on their active radar?
If they have active radar, they probably could. Japanese radar wasn't too good though and if you were running decks awash and their only target was a conning tower, you could get confused by the ocean backscatter obscuring the signal from the submarine.

Your radar signal would only show up on their radar scopes if the frequencies were very close. And even then you wouldn't be resolved as a pip. Your signal would just interfere with theirs, causing instability in their readout, which would show up as snow or random flashes. This interference was how American subs could tell if a friendly sub was in the area with its radar on.

[Rockin Robbins]

I have one more question about this video tutorial. What if I spot target for example on bearing 300 ? Do I have to change my direction to target to have it on bearing less than 180 ? It's importent coz as you all know ;) protactor shows only 180 degrees..

Egon, American subs used all 360 degrees for the same reason the military clock uses 24 hour times. All possibility of ambiguity due to the loss of the AM and PM, starboard or port, is eliminated. 350º is 10º off the port bow.

For bearings to port, go ahead and use the protractor. Then subtract the measurement from 360 to get the bearing, American style. Or you could switch to a U-Boat, where angles are always under 180º because they're measured off the starboard or port bow...:cry:

[Pisces]

... Or you could switch to a U-Boat, where angles are always under 180º because they're measured off the starboard or port bow...:cry:Maybe it was in real life, but not in SH3. The only angle that doesn't go over 180 is AOB. Everything else is reported 0-360 clockwise bow-relative.