GWX - getting range at PD with 10X scope?

[MarkShot]

When I was playing stock SH3, I had some handy tables which allowed you work out range based on mast height (from the ID book) and ticks on the scope for 4X, 6X. This approach was somewhat easier than the game approach using the stadimeter. Anyway, does anyone know if there are any tables for a 10X attack scope?

Thanks.

[dmlavan]

I had the same question about a month ago, and searched unsuccessfully on numerous websites and forum postings. I'd be willing to make a table on my own and share if I knew how to convert the tick marks/mils and range via an equation.

[danmir]

Hey,

I just purchased SHIII about 5 days ago, and installed GWX. I'm new here, so hey all. I've been lurking here the last week or so, figuring out the lingo. Took me a while to "get" AOB. And apologies in advance for noob questions coming!

I, too, was wondering about the scale, so I tried to puzzle it out. I took empirical data at the 10x mag, and charted it in excel. Basically I took measurements with the stadometer at 15, 13, 12, 11, 10, 9, 8, 5 ticks. I'm at work now, I did the charting at home, but the excel sheet linear estimation of the degrees per tick was about 0.156 degrees per tick.

I thought about this, and I have concluded that in GWX at 10x magnification, there are 0.15 degrees per tick. Reason?

- At 1.5x mag, they are 1 degrees per tick. You can verify this yourself, and it makes sense it would work this way.
- At 10x mag the scope tick scale does not stretch or anything.
- Key info: 1.5 / 10 = 0.15
- 1 degree tick gets subdivided by the ratio of the magnification, thus 0.15 degrees per tick
- I think the game engine funny rounding/flooring for the displayed angle moved my measured data slightly off accounting for the 0.156 linear estimation.

What I did find puzzling though was at the even marks, the measured angle would increment right at the marks, where if it was rounding as I would expect, it would be stable at the even marks and sensitive at the odd number marks. Ie @ 8, 8*0.15 = 1.2 degrees. at 7.8*0.15=1.17~=1.2, 8.2*0.15=1.23~=1.2. If it were rounding, i would expect it to be stable at 1.2 degrees at 8 ticks, but its 1.1 just under 8, 1.2 just over. From this I must conclude the displayed degrees aren't rounded; it is floored.

However, even though it displays the floored angle, I think it still uses a more precise angle for range calcs. I have noticed moving it up and down just a bit on the range measurement for which it gives the same angle on the display does give different ranges.

Assuming the top ticks follow the same scale, this leads to some interesting possibilities of measuring the apparent angular length of the ship, knowing range, and the actual length of the ship, you could compute the AOB.

AOB = acos(apparent_length/actual_length)
apparent_length ~= range * sin (angular_length)

AOB ~= acos(range*sin(angular_length)/actual_length)

AOB ~= acos(range*sin(horizontal_ticks*0.15)/actual_length)

[Sailor Steve]

Thanks, danmir, and WELCOME ABOARD!!!

[Puster Bill]

Originally Posted by danmir

Assuming the top ticks follow the same scale, this leads to some interesting possibilities of measuring the apparent angular length of the ship, knowing range, and the actual length of the ship, you could compute the AOB.

AOB = acos(apparent_length/actual_length)
apparent_length ~= range * sin (angular_length)

AOB ~= acos(range*sin(angular_length)/actual_length)

AOB ~= acos(range*sin(horizontal_ticks*0.15)/actual_length)

You could do that, or you could just just use one of these:

http://www.subsim.com/radioroom/show...ighlight=wheel





As I understand it, Hitman (the kind fellow responsible for these wheels) is now working on a template for a wheel to calculate AOB based on length vs. mast height measurements.

[jmr]

Despite being submerged at periscope depth in rough seas the stadimeter is pretty darn useless given the amount of up and down heaving the boat does. Interestingly enough the rocking of the boat at periscope depth in rough seas in SHIV has been toned down greatly making the stadimeter a breaze to use under any sea condition.

Greyrider made several periscope ranging charts which I have saved on my hard drive. If you PM me your email address I can send them to you. However, the charts were made with the 6x max zoom for the periscope and if you're using GWX the max zoom has been upped to 10x so you'll have to use the SHIII Minitweaker to reset it back to 6x.

edit: Oh yeah whiz wheels are cools too!

[MarkShot]

Interesting solution. I never thoughts about setting it back to 6X. A fairly simple and straight forward approach!