Calculating Speed - Correctly??

[Phoenix3000]

Hi all,

After getting rid of the stuttering gremlins and finally having a smooth-ish installation of SH4 I decided to begin from the beginning using all realism settings except for external camera (for the eye candy).

I quite understand the TDC and can accurately track a course and locate distance etc. but the main problem I have is accurately finding speed of the target.

For example, with a cargo merchant in calm seas, using the bow wave and travel across the periscope you can roughly guess a good speed - say 6 knots - in bad weather it's a lot harder!

But, when faced with naval ships - especially destroyers, cruisers and battleships etc. that can go up tp 30 knots it is much more difficult!

Countless times I have a good target track and waiting to shoot 90 degrees off their port or starboard, but the speed gets me most of the time. :damn:

The 'manual' says to click on the chronometer for as long as possible and by magic it works out a good estimate of the speed - this has never worked - I guess one of the restrictions with high realism settings.

So, without a nomograph (like SH3) I find it extremely difficult to to get the speed - a crucial part of the puzzle, without getting so close that every escort is on top of me.

Can anyone please advise?

What has (and hasn't) worked for others here?

Cheers!

Px3000

[PeriscopeDepth]

If you've got the time, plot the bearing and range of the target over several points and use time X speed = distance. If you're short on time (which is most of the time engaging TFs) get as good as a solution as you can by just guessing, and a minute later check the targets actual bearing against the position keeper computed bearing. Assuming you have a decent range/AOB estimation and the ship hasn't changed course speed will be your only variable. If the computed bearing is close to observed bearing, you know you have a good solution, if the observed bearing is in front of the computed bearing you know your speed estimate is too slow and so on. The position keeper is your friend.

PD

[rdhiggins]

Yup the speed is what killed me in the beginning.....

However what I do now is kinda 2 part. Basically I follow Neal's advice by reviewing the recognition manual and dividing it in half based on the total knots that the vessel can actually go.

Next I place the periscope or TBT crosshairs in front of the vessel by the water line until the vessel passes into the T of the crosshairs. Then I click on the stopwatch or chronometer. When the vessel clears the T then I click on the stop. Based on the seconds I have an estimate if I believe it is going fast, medium, or slow.

I follow this logic and most of the time the bad guy is at the bottom swimming with Davey Jones. :arrgh!:

[Drokkon]

It sounds like they shipped it without the chronometer working. Hopefully it will be patched soon. I'm supprized it wasn't done in the first patch.

[Platapus]

Y
Next I place the periscope or TBT crosshairs in front of the vessel by the water line until the vessel passes into the T of the crosshairs. Then I click on the stopwatch or chronometer. When the vessel clears the T then I click on the stop. Based on the seconds I have an estimate if I believe it is going fast, medium, or slow.

You posted "based on the seconds". Can you share what numbers of seconds you are using to estimate what speed please?

This sounds like a good technique to use and I would truly like to understand it.

[PeriscopeDepth]

Also check this out http://forums.ubi.com/eve/forums/a/tpc/f/6421019045/m/1831087345

PD

[rdhiggins]

Sorry. The seconds that I stated is the estimate based on how fast the enemy ship is traveling. If the stopwatch states 15 seconds from end to end, (and also review the wake in the periscope) then I will estimate that the enemy ship is moving slow.

If the stopwatch stated 40 seconds then I would estimate that the ship is traveling fast.

Hope this helps!

[joea]

I think you mean the opposite but yea.

[wetwarev7]

As stated above, if you have time, plot the ships position on the map, wait either 3 or 6 or 30 or 60 mintues and then plot the position again. the speed is roughly:

3 minutes: 20Xdistance=speed
6 minutes: 10Xdistance
30 minutes: 2Xdistance
60 mintues: 1Xdistance.

Any of these will give you a halfway decent estimate of speed. Obviuosly, the longer the time, the more accurate the estimate.

[Nightmare]

As stated above, if you have time, plot the ships position on the map, wait either 3 or 6 or 30 or 60 mintues and then plot the position again. the speed is roughly:

3 minutes: 20Xdistance=speed
6 minutes: 10Xdistance
30 minutes: 2Xdistance
60 mintues: 1Xdistance.

Any of these will give you a halfway decent estimate of speed. Obviuosly, the longer the time, the more accurate the estimate.
3 minutes wasn't accurate enough for me. I tested it out on the torpedo training mission and it always came 1 knot faster than the target's actual speed. This usually meant I was hitting the bow of target.

I've found 5 minutes to be accurate enough and have had 70% hit accuracy so far.
5 minutes: 12xdistance=speed

However I wish the ruler on the nav map was more exact. I have to guess because the distance marked between the two points is very rarely at that tenth of an nm mark. Example: ruler says .5nm but it's really closer to .58nm

[gnirtS]

Agree the ruler could do with another decimal place on its measuring.

Metric is "more accurate" due to this at the moment.

[DJSatane]

THIS needs to be fixed in next patch without question.

[JackChen]

I guess, the best thing is firing some torps in a spread or salvo, so you can get a better chance.

During the Falklands War, the ARA Admiral Belgrano was sunk with a spread - 2 out of 3 torps. Oddly enough, they prefered the tried and test straight running torps like the Mk 14 we have on the US Subs.