Does anybody know some formulas for using the TBT?

[gi_dan2987]

I'm curious to know the formulas for figuring distance using the TBT, and also figuring speed of a target using the fixed wire method. I can't find any topics that discuss this.

[Bubblehead1980]

Originally Posted by gi_dan2987

I'm curious to know the formulas for figuring distance using the TBT, and also figuring speed of a target using the fixed wire method. I can't find any topics that discuss this.

Not sure about visual other than guessing but if youre running TMO 2.5, the radar range unit will get you a distance.Don't mind cheating a little, can measure the distance on your nav map from your sub to the map contact and then insert it into TDC. Pretty much like using the periscope, obtain speed, range/bearing, AOB, input into TDC, take a final bearing and fire, adjust spread accordingly.Major difference is TBT is easier to spot targets with at long ranges.

[gi_dan2987]

I turned map contact updates on as I figure in real life sub skippers wouldn't have to do all the sighting and plotting by themselves. Being a 100% realism player, I finally awarded myself the ability to have map contact updates to simulate a weapons officer jotting the map plots while I call out the numbers. This alone makes my hunting much more accurate and the tonnage is already racking up. Convoys and TF's don't stand a chance against me now. I can shoot effectively until all torpedoes are expended, surface, end around, and attack the same convoy again later, scoring multiple ships hit each time. I once reduced a Convoy of 10 ships to 3 ships over the course of three attacks. That's a pretty decisive blow I must say

[Bubblehead1980]

Originally Posted by gi_dan2987

I turned map contact updates on as I figure in real life sub skippers wouldn't have to do all the sighting and plotting by themselves. Being a 100% realism player, I finally awarded myself the ability to have map contact updates to simulate a weapons officer jotting the map plots while I call out the numbers. This alone makes my hunting much more accurate and the tonnage is already racking up. Convoys and TF's don't stand a chance against me now. I can shoot effectively until all torpedoes are expended, surface, end around, and attack the same convoy again later, scoring multiple ships hit each time. I once reduced a Convoy of 10 ships to 3 ships over the course of three attacks. That's a pretty decisive blow I must say

I play 100 realism also.Are you running TMO the map contacts dont give away everything like stock etc, in fact they simulate having a plot made by your crew but it still not perfect, which is a good compromise I believe. The radar range unit in TMO 2.5 is great, really helps with night surface attacks.

[gi_dan2987]

Originally Posted by Bubblehead1980

I play 100 realism also.Are you running TMO the map contacts dont give away everything like stock etc, in fact they simulate having a plot made by your crew but it still not perfect, which is a good compromise I believe. The radar range unit in TMO 2.5 is great, really helps with night surface attacks.

I run RFB 2.0 over stock 1.5 and I enjoy that one the best... I've tried TMO, FOTRS, OM, and RSRD. The only one I haven't tried and really have no interest in trying is Great War Baltic. Haven't heard too many reviews about that one.

[CapnScurvy]

Gi_dan you've asked a simply question, which requires a complicated answer.

To begin, the game makes the use of the telemeter divisions (either in the periscope or TBT) useless.

Depending on the resolution/aspect ratio you view the game with, the telemeter divisions actually "count" differently when looking at the same target, at an equal distance from the sub. This fact becomes evident if you happen to make a simple edited mission with a target set in front of a sub, and take various measurements using different game resolution/aspect ratio settings. The particular resolution/aspect ratio setting one player uses will produce different measurements when compared to another players settings using a different resolution/aspect ratio.

This is also the case when expecting to use "real world" formulas of trigonometry and thinking they will work in providing accurate measurements in a "game world" that doesn't provide correct optical dimensions. The game does not, for either periscope's, or the TBT.

To make my point, the following can be found in the "Optical Targeting Correction" thread found HERE, under the "Discussion" section.

Inconsistency Between Periscopes and TBT/UZO Views


The issue of having an inconsistent scaled view between the periscope and TBT is a stock game issue. The fact that each of us use different equipment to play the game makes a cure difficult since each set-up is unique. As a modder, we don't have access to the way the various resolutions are displayed, this is contained in the game engine files. Our only fix is to manipulate the optical sizes for each resolution and aspect ratio and correct the size problem in that way.

Let's look at the problem and what or who does it effect.

If anyone would like to test for yourself the inconsistency issue between the periscope view and the TBT/UZO view; here is the same test mission with 8 Hiryu CV's set around a stationary Porpoise sub. The targets are set at the approximate 914 meters or 1000 yard distance from the sub. HERE'S THE LINK, to the "Hiryu Mission Test". Using the same test should prove useful when checking whatever it is you may want to look at.

Using the stock game only, no mods added, except for the "Hiryu Mission Test", I counted the Attack Periscopes telemeter divisions of the games native "1024x768 4:3" aspect ratio.





Roughly, 8 divisions from waterline to mast top, using the Hiryu at the bow of the sub and at the High Power magnification. It makes no difference what the height really is, just count the divisions (rest assured I care, and fixed the count to the proper height measurement in OTC). One should note that the stock games periscope "mask" image and the TBT "mask" image are both 1024x1024 sized images.

Surfacing the boat, and going to the TBT station this is what is found.





Roughly, double the telemeter division count, 16 divisions from waterline to mast top.

Lets go to the resolution size of "1360x768 85:48" aspect ratio and see what we have.





Ok, so the Attack Periscope counts the same division marks as the 1024x768 resolution. Good to know, this would not have been the case if I would have chosen the 1280x1024 as an example. As I already pointed out, the 1280x1024 periscope Field of View is larger than all the other resolutions, throwing off the ability to get the same count on the telemeter divisions.

What's the TBT going to show?





The stock game, using the 1360x768 85:48 aspect ratio counts 21 telemeter divisions to the mast top. Remember, the 1024x768 4:3 aspect ratio counts 16; both are off compared to the periscope count of only 8 divisions tall!

And, this isn't the only count that's different. Below are the different resolutions my two computers and their monitor set-ups reveal. Note the differences in the count of telemeter divisions.

1920x1080 16:9 aspect ratio / periscope=8 divisions; TBT=21 1/4

1792x1344 4:3 / periscope=8 divisions; TBT=16

1680x1050 8:5 / periscope=8 divisions; TBT=19

1600x1200 4:3 / periscope=8 divisions; TBT=16

1440x900 8:5 / periscope=8 divisions; TBT=19

1360x1024 85:64 / periscope=8 divisions; TBT=16

1360x786 85:48 / periscope=8 divisions; TBT=21

1280x1024 5:4 / periscope=7 1/2 divisions; TBT=16

1280x960 4:3 / periscope=8 divisions; TBT=16

1280x800 8:5 / periscope=8 divisions; TBT=19

1280x768 5:3 / periscope=8 divisions; TBT=20

1152x864 4:3 / periscope=8 divisions; TBT=16

1024x768 4:3 / periscope=8 divisions; TBT=16


As you look over the figures, also notice the aspect ratio similarities. The aspect ratio seems to be the critical issue between the differences of the periscope division count and the TBT count. All 4:3 ratios had a difference of 8 divisions for the periscope compared to a 16 count for the TBT. All 8:5 ratios had a difference of 8 divisions for the periscope and 19 count for the TBT. It would seem the aspect ratio is what decides how much of the difference there will be.

The point is, you'll find this issue with the "supermods" the same as you will with the stock game. Basicly making the telemeter divisions only providing "eye candy", having no relationship to making an accurate measurement at all.

[TorpX]

Originally Posted by gi_dan2987

I'm curious to know the formulas for figuring distance using the TBT, and also figuring speed of a target using the fixed wire method. I can't find any topics that discuss this.

I don't know what the telemeter marks on the TBT corrispond to, but here is a general formula for calculating range:

R = Mh / 3 tan a

where....... Mh is mast height in feet
...............a is the angle between the waterling and the mast top, degrees
...............R is range in yards

Here is a post with a formula for obtaining speed with the fixed wire method (see post 21), there are also some screen shots of different torpedo attack course finders. If you haven't seen them take a look.


http://www.subsim.com/radioroom/show...ighlight=speed