SUBSIM Radio Room Forums - Is the SH3 Stadimeter using the wrong equation? One geek says yes...

SUBSIM Radio Room Forums (https://www.subsim.com/radioroom/index.php)

- Silent Hunter III (https://www.subsim.com/radioroom/forumdisplay.php?f=182)

- - Is the SH3 Stadimeter using the wrong equation? One geek says yes... (https://www.subsim.com/radioroom/showthread.php?t=108505)

Is the SH3 Stadimeter using the wrong equation? One geek says yes...

Okay so for no reason whatsoever I was googling around looking for any kind of Angle on Bow sorta thing. Like a chart or a method or a wheel or something. Well anyway along the way one of the very few sites that came up that wasn't Subsim.com :rock: was this math geek site where a guy is trying to ask for help in determining the AoB for SH3.

http://www.physicsforums.com/archive...p/t-72987.html

Now he does have some alternate ideas on how to get certain info. But what struck me was this bit:

Quote:

Oh, and also...in the manual for Silent Hunter III, they said that the formula for the distance to your target based on the perceived angle in your periscope from the waterline to the topmost point was this:

range = h/sin(a)

where "a" is the perceived angle. But shouldn't it be tan(a) instead? I mean, at long range it'll give you practically the same thing, but still...it's wrong. The only reason I could see using sin(a) would be so you could approximate small angles reasonably well by simply substituting "a" in for "sin(a)", since for a small enough interval around 0, y = x is reasonably accurate for approximating y = sin(x). Still, the tangent function also goes through zero with slope of 1, too, so I don't really get why they put sin(a) in here, if they meant to on purpose.

Now most of that gives me a reminiscent headache that I had through most of grade 11. I don't fully understand that but I get the idea. So is it possible that the stadimeter is a bit wonky because of this?

Funk,
Now you're giving ME a headache :lost:

What that guy says is correct, the correct formula should use the tan() function. But for our purposes the result is the same. There would be no point using the correct formula, it would yield the same result.

Eg. when tha angle is 1 degree, for a 30m high ship:
- correct formula: distance = 1718.70 m
- wrong formula: distance = 1718.96 m

So the error is few centimetres.

Still I don't know why this approximate formula was used.

Maraz

Well I don't know why they used an American style AoB function in the TDC either. I guess it was something that slipped by.

Its weird... in high school I hated math, hell I flunked Math 11, but it wasn't until I started to play SH3 that I actually started to like math. They should have this game in schools!:yep: