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Old 04-20-10, 10:02 AM   #1
flakmonkey
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Default calculating speed in sh4?

Ok this may seem a bit of a silly question but just how the heck do you calculate speed in sh4 (using the default/stock method)?

I Id the ship with the manual, use the stadimeter tool to get the range, input the angle on bow using the dial but when i goto the speed part of the tool i keep getting a message saying "cannot estimate speed, need more data", what more data could possibly be needed??

Ive even looked in the game manual (a first for me!) and i seem to be doing everything by the book but its just not working!!
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Old 04-20-10, 10:07 AM   #2
BillBam
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If you are using the Stadimeter to calculate speed you need to take two readings far enough apart to give a good solution. The TDC will calculate this info based on the gap between the two readings, only using one will not work.

You can also calculate from the Nav Map by marking target position, wait 3 minutes (3.25 if in metric) and make a second mark. Using the compass calculate the distance between points and divide by 100 to get speed. For example if the distance is 1000 yards the speed is 10 kts. You can then enter this info maunally into the TDC.
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Old 04-20-10, 10:09 AM   #3
convoy hunter
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That's an easy one.
By using the map count how many meters the target travels for 30 seconds.
Then divide it by 1000 multiply by 120 divide again by 1.85 and you got speed in knots. For practise test it at yor own sub go at 5 kts steady speed and try if you can get a close solution to your speed.
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Old 04-20-10, 10:10 AM   #4
razark
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You need a second range/bearing.

They need to be separated by a certain amount of time, maybe 10 seconds.

They also need to be recent. You can't take two range/bearing readings and wait five minutes to calculate speed.
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Old 04-20-10, 10:13 AM   #5
flakmonkey
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Ahh thanks, the manual doesnt bother to mention the need for a second range reading! Im so used to sh3 and just starting a little timer to calculate the speed
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Old 04-20-10, 10:52 AM   #6
Fish40
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Flakmonkey, you could also see here: http://www.subsim.com/radioroom/show...t=ship+lengths I calculate speed by timeing a vessel crossing the periscope 0 bearing wire. If you know the length of the vessel, calculateing speed is a piece of cake!
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Old 04-20-10, 11:12 AM   #7
flakmonkey
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Nope still doesnt work! Ive taken the range 30+ times and entered the aob again and again and still i get the message about needing more data when i try to get speed!

I cant even use the stopwatch to do it manually, i click on it and nothing happens, short of finding a real life stopwatch im out of ideas, i knew it was a mistake to reinstall this s**t!
Im heading back to shV.
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Old 04-20-10, 12:01 PM   #8
tomoose
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Default Easy peasy

The following is a generic how-to list. There may be some debate about the order of the first few but it works for me.

1. ID target
2. Check target in ID book
3. Adjust AOB (click on red send to TDC button)
4. Take first range reading with stadimeter (click on red "send to TDC" button)
5. Wait at least 10 seconds
6. Take second range reading with stadimeter (click on red "send to TDC" button).
7. Click on Speed button, click on calculate button, (click on red "send to TDC" button).

This will produce a response in the dialogue box stating the targets' speed and course. Adjust AOB to match the stated course if required (use the PK to verify i.e. the PK target course indicator should change to match the AOB you input if you're doing it correctly).
Repeat the process as required.

Note: if you are not clicking on the red "send to TDC" button after each step then nothing is being entered into your TDC ergo "no data". You MUST send the info to the TDC.

This is NOT an exact science and you should not expect it to be. It takes a bit of practice. Conversely you could go with the Dick O'Kane method (do a search of the forums) which apparently simplifies the whole approach and takes the "computer" part out of the equation.

The stopwatch works fine for me, just click on the top winding 'button' of the stopwatch graphic to start and click it again to stop.

Hope this helps.
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Old 04-20-10, 12:42 PM   #9
flakmonkey
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Quote:
Originally Posted by tomoose View Post
The following is a generic how-to list. There may be some debate about the order of the first few but it works for me.

1. ID target
2. Check target in ID book
3. Adjust AOB (click on red send to TDC button)
4. Take first range reading with stadimeter (click on red "send to TDC" button)
5. Wait at least 10 seconds
6. Take second range reading with stadimeter (click on red "send to TDC" button).
7. Click on Speed button, click on calculate button, (click on red "send to TDC" button).

This will produce a response in the dialogue box stating the targets' speed and course. Adjust AOB to match the stated course if required (use the PK to verify i.e. the PK target course indicator should change to match the AOB you input if you're doing it correctly).
Repeat the process as required.

Note: if you are not clicking on the red "send to TDC" button after each step then nothing is being entered into your TDC ergo "no data". You MUST send the info to the TDC.

This is NOT an exact science and you should not expect it to be. It takes a bit of practice. Conversely you could go with the Dick O'Kane method (do a search of the forums) which apparently simplifies the whole approach and takes the "computer" part out of the equation.

The stopwatch works fine for me, just click on the top winding 'button' of the stopwatch graphic to start and click it again to stop.

Hope this helps.

Thanks Tomoose, its amazing how frustrating it is when you think youre doing everything right and nothing works, finally sorted it though
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Old 04-20-10, 01:29 PM   #10
Excelsior82
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Quote:
Originally Posted by flakmonkey View Post
I cant even use the stopwatch to do it manually, i click on it and nothing happens, short of finding a real life stopwatch im out of ideas, i knew it was a mistake to reinstall this s**t!
Uh.. ?
Are you running v1.4 (any mod ?) ?

I'm using stock 1.4 and when I click on the button on the top of the device, I hear it ticking regularly and a set of blue hands that moves along the time.

I use it a lot to know when I can emerge after having spotted an aircraft coming in my way.
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Old 04-20-10, 04:25 PM   #11
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I do use a separate stopwatch as it enhances my role playing. But you can get a cheap digital timer for about 5 bucks these days, or just use your watch.

Here is another quick way to get the speed.

If you know the length of the target ship in meters.
If you can get a good look at the side of the target (AoB 30-150)
If the bearing to the target is +/- 20 degrees from 0/180

1. Lock the periscope to the target. The lock function places the periscope hairline approximately in the center of your target. Close enough for our purposes.

2. Get your timer ready and when ever you are ready to time, unlock the periscope but don't move it.

3. Stop timing when the butt of your target crosses the hairline.

Speed in Knots = Length in meters/time in seconds.

This is a variation of the original, and more accurate:

Speed in knots = 1.94 x Length in meters/time in seconds routine. The locking method just gives you the speed faster and is accurate enough for 1500 meter and shorter shots.
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Old 04-20-10, 05:05 PM   #12
les green01
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i use my stop watch on my cell phone,also the calactor as my math sucks
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Old 04-21-10, 03:25 AM   #13
Phantom II
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Anyone know why SH4 and TMO doesn't specify ship length in the Recognition Manual? Otherwise you could line up the vertical line of your periscope with the front of the ship, start a timer, and measure the time it takes for it to get to the rear. Now if that distance is a known, you can divide it by the time taken to get a value in m/s. And to get a rough knot value, you simply multiply that by 2. (i.e 10m/s = 20kts)
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Old 04-21-10, 06:05 AM   #14
LGN1
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Is it possible to use the 'calculate speed'-feature also in combination with the active sonar, i.e., sending the range and bearing from the sonar to the TDC twice and then asking somehow the speed and course? I tried it, but I could not do it Is it just me or does it not work?

Cheers, LGN1
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Old 04-21-10, 06:39 AM   #15
tomoose
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Default Ship length

Phantom: The ship's length isn't in the ID book?? I'll have to check that. I was under the impression it was (although I'm always looking at the max speed and draft figures). I thought the length was written in there (I know it used to be along the bottom of the book 'page').

LGN1: That's a valid question and on the face of it, it should work given that the active ping has a button to "send to TDC". Having said that I've found the active sonar to give very rough results so even if it did work I'm not sure the speed would be calculated correctly. Additionally if there's ANY warships near your target the ping would be like sending up a flare, LOL.
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