U-Boot Periscope Telemeters

[Pisces]

Originally Posted by Nikdunaev

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Oh, so you are the one who invented it?
Very interesting indeed. I think a lot of people now believe it is historical.

I am the one that invented the speed trick.
(from the old days: https://www.subsim.com/radioroom/sho...&postcount=135) And the other scratch mark just under 15 degrees, for magnification adjustment. If I was unclear, I am not the person that made the RAOBF mod. That was a collective effort of Hitman, JoeGrundman and OneLifeCrissis. They don't seem to be around here much. Unless they visit subfora that I don't visit.

Do you know why the whole device was simulated in Silent Hunter the way it was then?
Why the tick counting, instead of linking it to the stadimeter, which is simulated already anyway?
Why are the two marks and the Kurswinkel ring fixed?

I have no clue what modding difficulties they encountered while trying to make this. My knowledge is skin deep. But I'm sure this was motivated by that. Lack of available resources in modifying the GUI to move the way he wanted it/work like the historical device. It must have been the best way to replicate it.

How did the real thing function in terms of scope magnification?
Did you have to divide everything by four in low power, like with the American stadimeter?

Much of how it works can be learned on the following site. It is a gold mine if you want to know more about everything connected to target acquisition, tracking and torpedo guidance (from both sides of the war): http://tvre.org/en/ They have an English and a Polish language version.

Did you have to divide everything by four in low power, like with the American stadimeter?

As mentioned in my above first quote. The magnification trick uses the mark at 14.5-ish degrees. If you calculate the sine of that angle, you get 0.25. In other words, one quarter. If you line up the low-zoom size to the mark, you get the high-zoom size at the index at the top. For correction of the AOB width in low zoom it is a bit more complicated, and I actually forgot. Maybe you can find it in the archives if you search for my name in OLC's threads. The top link should be a start in the right direction.

https://www.subsim.com/radioroom/sho...&postcount=222
And finally: https://www.subsim.com/radioroom/sho...&postcount=263

!!! Be aware though, the precise values and steps relied on that older mod. For use in current RAOBF/GUI mods make sure to consult the documentation of the mod. It's scales may differ.