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View Full Version : Quick Question on Manual Range Estimation for the TDC


Shrike37
06-07-09, 02:50 PM
I need a little clarification on manual torpedo targeting. Suppose I am doing a manual target input. I use the Stadimeter to get a range. Say I calculate the range to be 1500m and click the check box to send the info to the TDC.

However, I am closing on the target and can not fire the torpedo until 30 seconds later. By then the actual range is 1300m. Is the range info in the TDC being automatically updated during those 30 sec or will my shot be off because the TDC still thinks the target is 1500m away?

What about for the AOB? If you are in the same scenario and input the AOB as 110, but you can't fire the torpedo for 30 seconds and the AOB changes from 110 to 130 during that time, will the TDC auto update that for the firing solution?

Thanks

onelifecrisis
06-07-09, 02:57 PM
Sound like you're using the stock GUI or similar.

First, enter the speed into the TDC (this does not change).

Next, enter the AOB and make sure the TDC is on auto. As long as it's on auto (and you do not change course, and you keep the scope pointed at the target) the TDC will automatically adjust the AOB as the scope moves.

Range should ideally be the last thing you enter (because, unlike the AOB, the TDC does not automatically update it). IIRC, you can send the range from the notepad to the TDC without taking the TDC out of "Auto" mode.

HTH
OLC

Laufen zum Ziel
06-09-09, 05:58 PM
Not positive but is the range sitting just so you will know how many min/sec to impact. In other words you could have your range set at 100 m or 10,000 m and it only effects the stop watch not the torpedo.

Can someone shed some light on this please.

onelifecrisis
06-09-09, 06:10 PM
Not positive but is the range sitting just so you will know how many min/sec to impact. In other words you could have your range set at 100 m or 10,000 m and it only effects the stop watch not the torpedo.

Can someone shed some light on this please.

The range affects the gyro angle i.e. it is a required part of the firing solution and does affect the torpedo... unless you are firing at a gyro angle of zero, in which case it's like you said, and the range doesn't matter except for the stopwatch.

Contact
06-10-09, 04:55 AM
The range affects the gyro angle i.e. it is a required part of the firing solution and does affect the torpedo... unless you are firing at a gyro angle of zero, in which case it's like you said, and the range doesn't matter except for the stopwatch.

However I noticed that in stock SH3 calculation of range is not a vital thing to make in order to get a hit :hmmm:

As distinct from OLC Gold where it is very important to maintain range monitoring for accurate further calculations and repeated range adjustment is adviced just before the launch of the torp.

onelifecrisis
06-10-09, 06:33 AM
However I noticed that in stock SH3 calculation of range is not a vital thing to make in order to get a hit :hmmm:
Not true.

Contact
06-10-09, 07:01 AM
I did on purpose very inacurate range and I got a hit.

Here are a screenies:

http://img192.imageshack.us/img192/2821/clipboard1.th.jpg (http://img192.imageshack.us/my.php?image=clipboard1.jpg)

http://img192.imageshack.us/img192/9733/clipboard2d.th.jpg (http://img192.imageshack.us/my.php?image=clipboard2d.jpg)

I made this test in Naval academy torpedo tutorial. True range to target is 1400 meters but I did it as it was 8000 meters.

Am I missing something ? :DL

onelifecrisis
06-10-09, 07:07 AM
Because you fired from a small range and with a fairly small gyro angle?

Fire at all the other targets with incorrect ranges and see what happens. ;)

Hitman
06-10-09, 07:10 AM
OLC is completely right, here's a more detailed explanation of why range sometimes matters:

http://www.subsim.com/radioroom/showthread.php?t=121744

Sea Hawk
06-10-09, 08:40 AM
This is an experiment that I did which shows similar results

http://www.subsim.com/radioroom/showthread.php?t=151500

Laufen zum Ziel
06-10-09, 09:47 AM
Thanks OLC & all.

Pisces
06-10-09, 10:36 AM
However I noticed that in stock SH3 calculation of range is not a vital thing to make in order to get a hit :hmmm:

As distinct from OLC Gold where it is very important to maintain range monitoring for accurate further calculations and repeated range adjustment is adviced just before the launch of the torp.Infact, for the notepad procedure, I think the initial range is used to set up the scale of the firing triangle (initial range to target, target track, torpedo track).With it, and the estimated AOB, it has 2 sides of the triangle. It just doesn't know how long the target track is. That is why you do the speed option, to let the target move along it's track.Now you have a change in bearing and that closes the open end of the triangle, thereby also fixing the speed (target moved along it's track in that many seconds) The notepad-way has all the important things in the wrong sequence, making the important speed calculation based on uncertain data like range and estimated AOB. Not a reliable method.

Theoretically, it should be possible to (first measure range, then...) just set the AOB to 90 degrees and accept whatever speed value comes out when the bearing was locked and moved. Aslong as you can enter it in the dial. But since it is probably a huge value it is likely not possible. Also, the time to impact would be wrong, and you still need a quick range update to correct for gyroangle. And the speed and AOB setting is only valid at that last instant so absolutely not practical. .... So forget what I just said, I'm talking in 'Nutty Professor'-mode here. It won't be in the exam. ;)

Leandros
06-10-09, 11:15 AM
I am trying to mature my transfer to manual targeting by following the various discussions here. So far - more and more confused....!

Please answer this one: If one is lying still, perpendicular to the target's course and one knows it's speed and the selected torpedo's speed.....isn't it then simply to have a table to calculate the fore-angle one needs to launch the torpedo...?.....regardless of the distance....?

onelifecrisis
06-10-09, 11:20 AM
I am trying to mature my transfer to manual targeting by following the various discussions here. So far - more and more confused....!

Please answer this one: If one is lying still, perpendicular to the target's course and one knows it's speed and the selected torpedo's speed.....isn't it then simply to have a table to calculate the fore-angle one needs to launch the torpedo...?.....regardless of the distance....?


Only if you're firing the torpedo straight ahead (that's what a gryo-angle of zero means).

If you enter the correct range then the TDC will calculate the required gryo angle and then you can fire immediately (instead of having to wait for the target to reach the bearing you've calculated) and the torpedo will turn to meet its target.

Another benefit of entering the speed, AOB and range into the TDC is that you don't have to be perpendicular to your target.