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A periscope is an instrument for ... This allowed a tank commander to obtain a 360-degree field of view without moving his seat, including rear vision by engaging the ...
At depths below periscope depth submarines determine their position using: Dead reckoning course information obtained from the ship's gyrocompass , measured speed and estimates of local ocean currents, this could also be considered an estimated position as long as the ocean current is computed in.
The hyperfocal distance has a property called "consecutive depths of field", where a lens focused at an object whose distance from the lens is at the hyperfocal distance H will hold a depth of field from H/2 to infinity, if the lens is focused to H/2, the depth of field will be from H/3 to H; if the lens is then focused to H/3, the depth of ...
This is the maximum depth at which a submarine is permitted to operate under normal peacetime circumstances, and is tested during sea trials.The test depth is set at two-thirds (0.66) of the design depth for United States Navy submarines, while the Royal Navy sets test depth at 4/7 (0.57) the design depth, and the German Navy sets it at exactly one-half (0.50) of design depth.
[57] [139] When surfaced or at periscope depth, the Collins-class boats can use a Kelvin Hughes Type 1007 surface search radar, which is situated in a retractable mast on the fin. [10] [139] The fin of Sheean. The CH093 attack periscope mast is extended, and one of the panels for the distributed sonar array can be seen at the bottom right of ...
With increasing magnification, the depth of field – the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image – decreases. The depth of field reduces quadratic with the magnification, so compared to 7× binoculars, 10× binoculars offer about half (7² ÷ 10² = 0.49) the depth of field.
The periscope is out of focus, and the image does not provide sufficient encylopedic value. Mostlyharmless ( talk ) 07:52, 10 August 2008 (UTC) [ reply ] Not promoted .
Then the Echo slowed and came to periscope depth and went active on his fathometer on a short scale which was not suitable for the depth of water. The Echo then went deep, turned toward the Bashi Channel, and increased speed to 16 knots (30 km/h; 18 mph).