Calculating target speed

[jdkbph]

Forgive me if this is just a misunderstanding on my part... I just got the game and haven't progressed too deeply... but I'm confused by all the discussion about target speed calculation and stop watches and slide rules and all. Unless I've missed something critical in the various discussion threads (there are many and widely dispersed - hence the new topic) there's something very wrong here.

Assuming we're working with a fairly accurate representation of a WWII era USN TDC (eg, Mk4), why are we trying to calculate target speed at all? Target speed is a TDC ouput, not an input.

For instance, a typical approach phase observation might look like this:

Assumption: the classification phase is completed, with the target ID'ed, the initial range and relative bearing fed into the TDC, and an eyeball speed guesstimate used to start the plot.

Observation 1 - relative bearing, range, AoB.

several minutes pass...

Observation 2 - relative bearing, range, AoB.

I should note that periscope exposure on each of these observations was kept to a minimum... in practice less than 20 seconds per. Somewhat at odds with my understanding of the use and function of the SH4 chronometer...?

Anyway... this info is fed into the TDC and plotted on the manoeuvring board after each observation. Given the initial parameters, and the results of the two subsequent observations, target speed is now known (ie, calculated by the TDC) to a reasonable level of accuracy, and will be continually refined with each additional observation.

The only time Speed, as an observed data element, is ever actually used as a TDC input is during the classification phase.

Is this not the case with SH4? Having waited since 1985 (MPS' Silent Service, and everything in between) for a real WWII USN fleet boat sim, it would be quite disappointing to find that they haven't managed to get this right.

JD

[Hitman]

Well to make a long story much shorter: The chronometer in SH4 *should* calculate speed, but it is broken currently in the game.

Assuming we're working with a fairly accurate representation of a WWII era USN TDC (eg, Mk4), why are we trying to calculate target speed at all? Target speed is a TDC ouput, not an input.


That's partially correct. You could/should enter speed estimates in the TDC to start the position keeper function and by observing the difference between the predicted (By the PK) bearing of the target and the actual bearing of it, you could refine the solution. It's the tracking party who would calculate speed by measuring in the CIC with the "speed" ruler the distance between 2 observations at a given time.

Making it all short again: In SH4 playing with manual Torpedo shooting, you currently must calculate the speed on your own and input it in the TDC via the slide out tool on the upper right corner of the screen.

Hope that helps:up:

[KypFisto]

I hope they fix it eventually. I'm reading the 1.2 patch notes and it looks like its not going to be fixed in this particular patch...though I may be mistaken.

[Joe S]

My understanding is that speed is something that must be entered into the TDC. The fire control party would use a manual plot and a manuvering board to come up with speed estimates which would then be entered into the TDC and adjusted as needed to get a good solution. The use of the topwatch is not very practical or realistic. I prefer to mark the locatioin of the target, wait one, two or three minutes or real time and mark the new location, measure the distance travelled and firgure out the speed accordingly. I have a chart prepared ahead of time that shows speed in terms of yards per minute, eg 11 knots = 330 meters per minute. I also have one for yards/minute but dont have it in front of me at this time. Unfortunatly, we dont have an accurate ruler in SHIV but with a little luck you can get a reasonably good speed estimate provided you are far enough from the target when you first see it to have time to do the calculation.

Target speed is the most important component of a good TDC solution. Range is the least important. As for AOB, if you are within 1,500 yards from the target's track, a reasonable estimate of AOB will be good enough. However, if you misjudge the speed by even a few knots, you will usually miss.

I prepared a chart way back in the SHI and sub battle simulator days, that geives the gyro angle lead based on the speed of the target. Range is immaterial. I dont know where it is right now but I doubt that I threw it away. at any rate, The best way to determine speed is to calculate it based on the manual plot. It would be great if the game would automatically note the time of the placement of a map mark. Joe S

[jdkbph]

I wonder why didn't they include a manoeuvring board? I guess we're flying seat of the pants once again with respect to things like distance to track, etc.

JD

[joea]

I don't get it, the chronometer in SH3 was unreliable and made you keep your scope up for a dangerously long time. Why are people clamoring for it?

[Joe S]

I agree with Joea. The chronograph is usefull only to the extent it helps you measure the distance travelled by the target in one , two or three minutes, etc, so you can do a time/distance calculation. If you have to keep the scope up the whole time it is of no practical value. You should only have to keep the scope up for a few seconds to plot the location of the target at the beginning and end of the time period you choose, one,two or three minutes, or whatever. Joe S

[Teh_Diplomat]

This game owns too much to have included, a functional Chronometer :roll:

[XanderF]

I don't get it, the chronometer in SH3 was unreliable and made you keep your scope up for a dangerously long time. Why are people clamoring for it?

Depends on usage. The in-game "manual" TDC did require you leaving it up too long.

However, you could use it to mark time between measurements. Counting out 3 minutes and 15 seconds for a second observation (for the easy "3:15 rule" solution) is a LOT easier with a working stopwatch/chronometer.

Currently, in Sh4, it does nothing at all. You totally have to wing all time measurements, or have your own stopwatch in-hand (but that won't sync with in-game time compression settings like an in-game chrono will, so...)

[panthercules]

I don't get it, the chronometer in SH3 was unreliable and made you keep your scope up for a dangerously long time. Why are people clamoring for it?

Currently, in Sh4, it does nothing at all. You totally have to wing all time measurements, or have your own stopwatch in-hand (but that won't sync with in-game time compression settings like an in-game chrono will, so...)

What? My stopwatch sure seems to work in game, for just measuring elapsed time anyway. I thought that it was only use of the stopwatch for automated speed entry into the TDC that was broken - are you saying the stopwatch isn't accurately measuring elapsed time period? Now I'm going to have to do a time check to compare the stopwatch with a real clock to see if it really is working.

[edit] Well, I just tested it and the stop watch worked just fine - measured out 3'15" on the in-game stopwatch and it matched up perfectly with the clock IRL. Also tested it with time compresssion (up to about 128 or so, at which point the hand was spinning around so fast it was a little hard to tell), and the stop watch kept perfect pace with the time indicator at the bottom right side of the screen. So I'm not sure what you mean by your statement above XanderF ???

[joea]

Guys to be 100% clear...I don't have SH4 and I know the stopwatch works in the game. What I mean is if it is meant to work like in SH3 I think it is not terribly useful.

In SH3 what you do with the notepad is with periscope up and locked on the target you click the stop watch and let it tick ...longer the better...click again and you get the speed and click the tickmark to send in to the TDC.

Now since you have to keep the scope up the whole time locked on target my experience is I am spotted if I try to keep a reasonable time to get a good speed estimate. If I keep it up only for 10 seconds or so the speed is off and I miss. That's what I don't like about it. Now if the chronometer would work if you lock the target, put scope down, up and mark and lock the same target after at least a couple of minutes and "automatically" get the speed that would be great for usability and immersion.

[Joe S]

I have a question: How do you use the in game chronometer? I can bring it up but do not know how to start and stop it, I have been using my own stopwatch so far. Thanks! Joe S

[Joe S]

I finally figured out how to start and stop the watch! thanks! Joe S

[jdkbph]

Guys to be 100% clear...I don't have SH4 and I know the stopwatch works in the game. What I mean is if it is meant to work like in SH3 I think it is not terribly useful.

In SH3 what you do with the notepad is with periscope up and locked on the target you click the stop watch and let it tick ...longer the better...click again and you get the speed and click the tickmark to send in to the TDC.

Now since you have to keep the scope up the whole time locked on target my experience is I am spotted if I try to keep a reasonable time to get a good speed estimate. If I keep it up only for 10 seconds or so the speed is off and I miss. That's what I don't like about it. Now if the chronometer would work if you lock the target, put scope down, up and mark and lock the same target after at least a couple of minutes and "automatically" get the speed that would be great for usability and immersion.



Completely agree. That's the way it was done IRL.

[panthercules]

Well, I never found the auto-speed function in SH3 to work well enough to use anyway, so I never used it, and I agree that anything that makes you have to keep the scope up a long time to use it wouldn't really be very useful for anybody trying to play in a mostly-realistic manner anyway. However, for those who want to let their crew do more of the work it would be nice if they could make the auto-speed-entry thing work in at least some fashion so I hope for those folks that they will get that function fixed in a patch soon - if nothing else, it would remove the frustration of having the manual say something will work a certain way when it doesn't.

[XanderF]

I have a question: How do you use the in game chronometer? I can bring it up but do not know how to start and stop it, I have been using my own stopwatch so far. Thanks! Joe S

Hmmm...maybe I'm doing something wrong, then.

In Sh3, the stopwatch works one of two ways:
- On the notepad, when you go to the 'speed' section, click on the stopwatch icon and let it run for a while
- To use on its own, click it, and it runs. Click it again, and it stops.

Neither works in Sh4. Clicking it...well, you can keep clicking it, it doesn't seem to have any effect. And needless to say, the time function of the torpedo entry gauge/dial/thing in Sh4 doesn't work at all.

Is there some other way to get it working in Sh4?

[panthercules]

I have a question: How do you use the in game chronometer? I can bring it up but do not know how to start and stop it, I have been using my own stopwatch so far. Thanks! Joe S

Hmmm...maybe I'm doing something wrong, then.

In Sh3, the stopwatch works one of two ways:
- On the notepad, when you go to the 'speed' section, click on the stopwatch icon and let it run for a while
- To use on its own, click it, and it runs. Click it again, and it stops.

Neither works in Sh4. Clicking it...well, you can keep clicking it, it doesn't seem to have any effect. And needless to say, the time function of the torpedo entry gauge/dial/thing in Sh4 doesn't work at all.

Is there some other way to get it working in Sh4?

Click only on the stem at the very top of the watch - it will switch to stopwatch mode and start counting off the elapsed seconds with the main big hand and the minutes with the main little hand - then click the top stem again when you're ready to stop - not sure what the little hands in the bottom dial do, but I think they activate when the torpedoes fire or something.

Good luck!