mutiple targets - sonar ??

[I'm goin' down]

My imagination is running wild and I cannot sleep. Here is why...

One target on sonar - attack using sonar only is feasible.
Two target on sonar - attack using sonar is feasbile if the targets have different hydrophone contacts. say one where the first contact is 270 degrees and the other at 300 degrees..
Mutiple targets - What do you do when you have multiple targets and they are so close together that the hydrophone contacts are so close together that you cannot tell one from the other?

For now, I will stick to solo targets...until I am educated.

Now, back to the game. I am below the layer, hiding from a destroyer....

[Rockin Robbins]

Wth the game as presently modeled, if you can't follow a single contact of your choice, you're pretty much blown out of the water as far as sonar only methods are concerned. It is the same result as if the periscope randomly pointed to a target not of your choosing and you couldn't aim it where you wanted.

[Soundman]

That is pretty much the way it works in real life. I imagine that these days there is high tech software on the modern boats that can separate these sort of contacts, but I would venture to say that until recently, (the advent of computers) when you listened to more than one contact on the same bearing, that's what you got, a combination of two sounds. That's why/how modern subhunter/killers such as a "Los Angeles Class" sub tried to ease in behind the Russian subs, they could not detect the noise from directly behind them, due to their own prop noise. Ever watch Red October? No different than trying to look three cars in front of you while going down the road with an SUV in front of you.

[I'm goin' down]

I watched the Dick O'kane Sonar Only (By God) video tutorial. Good tutorial. However, I had a big problem, which maybe someone can identify and resolve. Here is a summary of the failed attack.

1 . I set the periscope to zero degrees. (Should I have set it to 20 degrees starboard?)
2. I tracked the target by sonar and did not peek with the telescope or camera until after I fired torpedos.
3. I calibrated target speed at 15 knots using a 3 minute time interval between sonar pings (corrected to address Manchausen's posted question below). The PK was activated.
4. I set up at 90 degrees and pulled the range marker all the way to the right.
5. The target was approaching from my starboard side (i..e right) and its port (i.e. left). I set the AOB at 105 degrees because it was closing the distance from my right to to my left. The gyro angle looked way off (too far to the left), so I I tired an AOB of 75 degrees which was no good either.
5. I returned to 105 d3egrees, prayed to Dick O'Kane, and fired four shots that went way wide to the left (corrected a mistake in description because I do not know my left from my right), following the afoeredescribed gyro angle.
6, The PK had been following the target, said it was close, so I checked it out on the attack periscope. It was right where it was supposed to be, so my sonar tracking was masterful, if I don't mind bragging.

Where did I screw up? When a ship is approaching from my starboard, am I supposed to set the AOB for 105 degrees in classic O'Kane style? Or should my periscope been set at 20 degrees rather than 0 degrees? I made a fundamental error in my attack scenario, but I do not know where it could be. I thought the problem would be tracking the target at the correct bearings and distances, but instead some other part of the firing solution was awry.

[Munchausen]

Originally Posted by I'm goin' down

2. I tracked the target by sonar and did not peek with the telescope or camera until after I fired torpedos.
3. I calibrated target speed at 15 knots using a 3 minute time interval. The PK was activated.

:hmm: If you didn't peek, how did you determine the target's speed?

[Rockin Robbins]

Originally Posted by Munchausen

:hmm: If you didn't peek, how did you determine the target's speed?

Heh, heh, heh! I always wanted to do this because Luke does it all the time to great effect. I hate making you the victim, but the opportunity got the best of me......
The Dick O'Kane Sonar Only (by God!!!) Video Well, technically you can't read it, it's a video......

To make a long story short you ping him twice, three minutes apart. Each ping gives you a range and bearing, which you chart as a position on your nav map. You do the normal thing: measure the number of hundred yards and that's your speed in knots. A ray from the origin point, through the second position point extended past your course is the target's track. Assuming he doesn't change course, you should never have to ping him again, because passive sonar gives you a bearing. Where the bearing line crosses the track is his position. Tricky, huh?

Warning: there is some uncertainty in sonar ranges. You'll note in the tutorial video that I pinged him six or seven times to get a good average track line that I could believe in. Your track line will always be a little bit inaccurate with sonar only. It should not cause you to miss, however.

[I'm goin' down]

I came accross Manchausen's sister boat. It tried to hurt me. It name is Manchausen by Proxy. Heh. Ha. Ha. Ha.:rotfl:

So, RR, Sir, where did I screw up?

Note, I fixed the mistakes in my posted question. I missed the shots wide to the left and not wide the right.

[I'm goin' down]

Here is my question, as I wanted to make sure the issue was properly tabled for discussion.

Originally Posted by I'm goin' down

I watched the Dick O'kane Sonar Only (By God) video tutorial. Good tutorial. However, I had a big problem, which maybe someone can identify and resolve. Here is a summary of the failed attack.

1 . I set the periscope to zero degrees. (Should I have set it to 20 degrees starboard?)
2. I tracked the target by sonar and did not peek with the telescope or camera until after I fired torpedos.
3. I calibrated target speed at 15 knots using a 3 minute time interval between sonar pings (corrected to address Manchausen's posted question below). The PK was activated.
4. I set up at 90 degrees and pulled the range marker all the way to the right.
5. The target was approaching from my starboard side (i..e right) and its port (i.e. left). I set the AOB at 105 degrees because it was closing the distance from my right to to my left. The gyro angle looked way off (too far to the left), so I I tired an AOB of 75 degrees which was no good either.
5. I returned to 105 deegrees, prayed to Dick O'Kane, and fired four shots that went way wide to the left (corrected a mistake in description because I do not know my left from my right), following the afoeredescribed gyro angle.
6, The PK had been following the target, said it was close, so I checked it out on the attack periscope. It was right where it was supposed to be, so my sonar tracking was masterful, if I don't mind bragging.

Where did I screw up? When a ship is approaching from my starboard, am I supposed to set the AOB for 105 degrees in classic O'Kane style? Or should my periscope been set at 20 degrees rather than 0 degrees? I made a fundamental error in my attack scenario, but I do not know where it could be. I thought the problem would be tracking the target at the correct bearings and distances, but instead some other part of the firing solution was awry.

Note, I tried another attack today and missed again. The target was moving right to left again. I had to spin my boat around because the target was bearing down on my position, and I fired at less than 20 degrees to my starboard. I missed. But it appeared that my gyro angle was off, this time to the right. I set the periscope and 20 degrees at the last minute because of my boat was too close to the target, I reinput the AOB and range. The target was about 800 yards off, so the sonar man was doing his job as I plotted its course. Where did I go wrong, or as Max says in The Producers, "Where did I go right?":hmm:

[Munchausen]

If you keep missing, the best thing to do is make it as simple as possible next time around. The fewer the tweaks, the fewer the number of things that can go wrong. Insure you have all of the following properly set:

• Torpedo speed.
• Target speed.
• AOB set to 90 degrees (forget using a lead angle for now).
• Torpedo doors open.

Then:

• Make sure your sub is perpendicular to the target's track (course line).
• Sub should also be as close to "dead in the water" as possible.
• PK off!*
• Set periscope crosshairs to zero bearing.
• Send range and bearing to the TDC.

Check the torpedo's gyro angle on your TDC ... for a left-to-right pass across your bow, it should look something like this:



Notice that the arrow protruding from the bottom set of wheels is canted to the right ... indicating a lead (gyro) angle for the torpedo. If the target was moving faster, the lead would be even greater. The reason it's canted is because you haven't adjusted your set-up to lead the target ... instead, you'll let the TDC compute lead via the gyro.

If I was planning to shoot without peeking, I'd use the sonar trace on the map as a guideline. Assuming you know exactly where your bow is pointing (and all the above parameters are set), shooting when the trace crosses your bow line should result in an MOT (hit in the "middle of target").

If you still miss, set it all up again (RR has created a couple of really good practice set-ups you can download) and take a screen shot. Then clip out the TDC and paste it here, same as the one above. That should make it easier to analyze what it is you're doing wrong.

* With PK on, the TDC will continually adjust your firing solution according to whatever target speed is set ... thereby increasing gyro angle while you wait.

[I'm goin' down]

Manchausen, that was an excellent explanation. I am glad you are on our side. I have forwarded your post to the Naval College in Monterey, CA with a recommendation that they offer you a full porfessorship, so pack your bags Manchausen. toss the dog in the car, and tie the wife to the roofd, because you are being reassigned and promoted soon.

Where, oh where, do I find the RR practice attacks you mentioned? I have watched his video tutorial several times, but did not see any practice tutorial other than that.

[RR, when you read this, I sent you a message via Skype. My web cam was not working, and it is now fixed. I have no idea why it stopped working, but I changed the multitude of connections from devices on the back side, reinstalled the web cam software, and viola, windows spotted a new device--the web cam! It is now up, running, and funtional. I groomed my three poodles, who work 8 hours shifts rotating the watch, for our ocean contact and they haven't spotted you yet.]