stedimeter

[RulezRulez]

Hi guys, is there anyone that would be able to explain to me the principle of operation of stedimeter ? I dont really get it...i would like to know how does it double the picture of the ship..(I can roughly imagine, but i would like to know) , but the main thing is , that I do not understand how is it possible that I don´t need to level the periscope line with the ship water line to get correct results ? It makes the measurement much easier but what is the principle ?

[RulezRulez]

Hi guys, is there anyone that would be able to explain to me the principle of operation of stedimeter ? I dont really get it...i would like to know how does it double the picture of the ship..(I can roughly imagine, but i would like to know) , but the main thing is , that I do not understand how is it possible that I don´t need to level the periscope line with the ship water line to get correct results ? It makes the measurement much easier but what is the principle ?

[bobwill]

You mean for range finding?
Well, it's basic trigonometry. If the height of the ship is known, then you find the degree of the angle from the point of the observer to cover the the target, then you now have an angle and a leg of a right triangle. So, you simply need to calculate the length of the other leg.

[RulezRulez]

No man, you´ve got me wrong...I mean the mechanical function of the device. how the image of the target is moved above the target and so on