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Subject: Re: horizon visibility puzzle
From: Hal Mueller (hal@XXX.XXX)
Date: Wed Jun 20 2001 - 16:24:35 EDT
At 12:17 PM -0700 6/20/01, Paul Hirose wrote:
>You are ashore, 777 meters above sea level, looking toward the ocean.
Horizon distance is 58.4 nm from your location, or 108.2 km. There's
a point out on the ocean, call it A, which is on the line containing
your position and the hilltop. "A" is the farthest point on that
line that you can see (and it's the farthest point that someone at
sea level can see you).
>In your line of sight, 35 kilometers away, is a hill 401 meters high.
Horizon distance is 42.0 nm from this hilltop, or 77.8 km.
>Can you see the ocean over the top of this hill?
Point A is
(108.2 - 35) km from the hilltop, or 73.2 km. You can see the
hilltop from Point A. Thus, the hilltop blocks your view from your
ashore location.
---- Hal Mueller hal@XXX.XXX Mobile Geographics LLC http://www.mobilegeographics.com/ Seattle, Washington (206) 297-9575 Get CelestNav 2.2.2! http://www.mobilegeographics.com/celestnav/
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