tdc question

Laffertytig · 07-04-08, 05:56 PM

if i input data (AOB + speed) into the tdc and set it to auto and then change course and speed, will this mess up the solution?

im find tryin to figure out AOB at night is impossible so my idea is to set up the tdc in daytime then when night falls, turn towards the convoy and attack. will this method work?

Schwuppes · 07-04-08, 07:31 PM

Quote:

Originally Posted by Laffertytig

if i input data (AOB + speed) into the tdc and set it to auto and then change course and speed, will this mess up the solution?

Yes, it will mess up the solution.

joegrundman · 07-04-08, 07:43 PM

But what you can do is if you know target course, and therefore your own future intercept course, point your scope/uzo directly forwards, and go to the F6 screen and set the AOB to 90 port or starboard, whichever would be correct for when you hope the target passes in front of you later that night, and then that's it

then whatever course you are on, it doesn't matter, so long as you are on a normal firing course (perpendicular track) at the moment of firing.

Pisces · 07-05-08, 03:10 AM

Quote:

Originally Posted by Laffertytig

...
im find tryin to figure out AOB at night is impossible so my idea is to set up the tdc in daytime then when night falls, turn towards the convoy and attack. will this method work?

If you wait that long for the attack it is easier to simply plot it's positions every once and a while. And so get it's course pretty accurate to which you can position yourselve at 90 degrees. Then like joegrundman says, point scope at 0 and set AOB to 90 left or right. This also solves the problem if the target makes a course change in the mean time. Because of plotting you notice the change well in advance.

Hitman · 07-05-08, 04:46 AM

Quote:

if i input data (AOB + speed) into the tdc and set it to auto and then change course and speed, will this mess up the solution?

No. Only if the target changes course and speed will your solution be messed up.

Quote:

im find tryin to figure out AOB at night is impossible so my idea is to set up the tdc in daytime then when night falls, turn towards the convoy and attack. will this method work?

That's actually what the germans preferred to do. They did the end around during daylight keeping the top of the convoys masts in sight above the horizon and carefuly observing enemy course and speed by comparison to their own one. Then they waited the convoy in the chosen spot and attacked by night, setting mainly the values they had collected by day if visibility wasn't good enough for double checking.

onelifecrisis · 07-05-08, 04:50 AM

Quote:

Originally Posted by Hitman

Quote:

if i input data (AOB + speed) into the tdc and set it to auto and then change course and speed, will this mess up the solution?

No. Only if the target changes course and speed will your solution be messed up.

I think you're mistaken on this one mate. Changing your own course will defo mess up the firing solution!

UnderseaLcpl · 07-05-08, 06:51 AM

Bah! You kids and your "computers"... and yer.....music.

Real Kaleuns aim the WHOLE boat and make a good guess. Iron sights FTW!

Hitman · 07-05-08, 01:30 PM

Quote:

I think you're mistaken on this one mate. Changing your own course will defo mess up the firing solution!

Really?

IIRC when you change course you are effectively changing only one side of the triangle, i.e. the bearing to target, therefore the TDC can autoupdate it. If the target changes course it is a different matter, because the AOB changes and that one is updated through your bearing to target. And because the bearing doesn't change, your solution gets screwed.

Will make some tests and confirm :hmm:

Laffertytig · 07-05-08, 02:51 PM

i tried to find some sources that answered my question and while i did find lots of instructions on how to find AOB i didnt find an answer to my question.

im sure someone will come up with a definitive answer to this soon enough:hmm:

joegrundman · 07-05-08, 08:43 PM

Quote:

Originally Posted by Hitman

Quote:

I think you're mistaken on this one mate. Changing your own course will defo mess up the firing solution!

Really?

IIRC when you change course you are effectively changing only one side of the triangle, i.e. the bearing to target, therefore the TDC can autoupdate it. If the target changes course it is a different matter, because the AOB changes and that one is updated through your bearing to target. And because the bearing doesn't change, your solution gets screwed.

Will make some tests and confirm :hmm:

if you change course, you are changing 2 angles of the triangle: bearing to target and target track angle (tta)

Say you have a triangle of the following

tta 90
bearing 70
AOB port 20

and you set up for a fast 90, then when the target passes in front of you you have

tta90
bearing0
AOB port 90

and you change change course 20 degrees port

then you have

tta 110
bearing 90
AOB port 20

when the ship passes in front of you you have

tta 110
bearing 0
AOB 110

but unless you reset your TDC to reflect this, it will still say AOB 90 when the bearing to target is 0

joegrundman · 07-05-08, 08:49 PM

Quote:

Originally Posted by Laffertytig

i tried to find some sources that answered my question and while i did find lots of instructions on how to find AOB i didnt find an answer to my question.

im sure someone will come up with a definitive answer to this soon enough:hmm:

the definitive answer to whether your changing course of speed changes your TDC solution is:

change of your course heading=change of TDC solution required
change of your speed=no change of TDC solution requried

BUt changes of either TARGET course OR speed will require a new TDC soltuion

N.B.for small changes of your course (say +/- 15 degrees) when you are firing roughly perpendicular to the target at short to medium range, the error in your solution is not significant.

Calculating your data in the day for use at night is fine, so long as the convoy hasn't changed course or speed after hitting a waypoint - for this reason a final speed verification using the fixed wire method is useful

onelifecrisis · 07-06-08, 03:14 AM

Quote:

Originally Posted by Laffertytig

i tried to find some sources that answered my question and while i did find lots of instructions on how to find AOB i didnt find an answer to my question.

im sure someone will come up with a definitive answer to this soon enough:hmm:

You've had your definitive answer... maybe you just didn't like it. :p

It sounds like you want to enter a solution into the TDC and then several hours later, on a different heading and in a new position, hit fire. Well, no, that won't work.

If you gather information (target course and speed) during the day, without entering it into the TDC, and then position yourself for a night attack, then (assuming the target did not change course or speed) you can calculate your firing solution using your new/current course and speed, and the "old" (current) target course and speed, and enter it into the TDC before firing, and that works.

Pisces · 07-06-08, 04:12 AM

Quote:

Originally Posted by joegrundman

Quote:

Originally Posted by Hitman

Quote:

I think you're mistaken on this one mate. Changing your own course will defo mess up the firing solution!

Really?

IIRC when you change course you are effectively changing only one side of the triangle, i.e. the bearing to target, therefore the TDC can autoupdate it. If the target changes course it is a different matter, because the AOB changes and that one is updated through your bearing to target. And because the bearing doesn't change, your solution gets screwed.

Will make some tests and confirm :hmm:

if you change course, you are changing 2 angles of the triangle: bearing to target and target track angle (tta)

Say you have a triangle of the following

tta 90
bearing 70
AOB port 20

and you set up for a fast 90, then when the target passes in front of you you have

tta90
bearing0
AOB port 90

and you change change course 20 degrees port

then you have

tta 110
bearing 90
AOB port 20

when the ship passes in front of you you have

tta 110
bearing 0
AOB 110

but unless you reset your TDC to reflect this, it will still say AOB 90 when the bearing to target is 0

Small correction:

....
then you have

tta 110
bearing 20
AOB port 90
....

Laffertytig · 07-06-08, 04:25 AM

yeah your right OLC, it was more in hope than anythin else

i blame hitman for putin the seed of doubt in my mind!

joegrundman · 07-06-08, 06:30 AM

Quote:

Originally Posted by Pisces

Quote:

Originally Posted by joegrundman

if you change course, you are changing 2 angles of the triangle: bearing to target and target track angle (tta)

Say you have a triangle of the following

tta 90
bearing 70
AOB port 20

and you set up for a fast 90, then when the target passes in front of you you have

tta90
bearing0
AOB port 90

and you change change course 20 degrees port

then you have

tta 110
bearing 90
AOB port 20

when the ship passes in front of you you have

tta 110
bearing 0
AOB 110

but unless you reset your TDC to reflect this, it will still say AOB 90 when the bearing to target is 0

Small correction:

....
then you have

tta 110
bearing 20
AOB port 90
....

That too, depending on when you change course

07-04-08, 05:56 PM	#1
Laffertytig Grey Wolf Join Date: Feb 2003 Posts: 757 Downloads: 110 Uploads: 0	tdc question if i input data (AOB + speed) into the tdc and set it to auto and then change course and speed, will this mess up the solution? im find tryin to figure out AOB at night is impossible so my idea is to set up the tdc in daytime then when night falls, turn towards the convoy and attack. will this method work?

07-04-08, 07:43 PM	#3
joegrundman Ocean Warrior Join Date: May 2007 Posts: 2,689 Downloads: 34 Uploads: 0	But what you can do is if you know target course, and therefore your own future intercept course, point your scope/uzo directly forwards, and go to the F6 screen and set the AOB to 90 port or starboard, whichever would be correct for when you hope the target passes in front of you later that night, and then that's it then whatever course you are on, it doesn't matter, so long as you are on a normal firing course (perpendicular track) at the moment of firing. __________________ "Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

07-05-08, 06:51 AM	#7
UnderseaLcpl Silent Hunter Join Date: May 2008 Location: Storming the beaches! Posts: 4,254 Downloads: 0 Uploads: 0	Bah! You kids and your "computers"... and yer.....music. Real Kaleuns aim the WHOLE boat and make a good guess. Iron sights FTW! __________________ I stole this sig from Task Force

07-05-08, 02:51 PM	#9
Laffertytig Grey Wolf Join Date: Feb 2003 Posts: 757 Downloads: 110 Uploads: 0	i tried to find some sources that answered my question and while i did find lots of instructions on how to find AOB i didnt find an answer to my question. im sure someone will come up with a definitive answer to this soon enough:hmm:

07-06-08, 04:25 AM	#14
Laffertytig Grey Wolf Join Date: Feb 2003 Posts: 757 Downloads: 110 Uploads: 0	yeah your right OLC, it was more in hope than anythin else i blame hitman for putin the seed of doubt in my mind!