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Re: Anomalous dip. was: [NAV-L] Testing pocket sextant.
From: Marcel Tschudin
Date: 2006 Jun 17, 15:29 +0300
From: Marcel Tschudin
Date: 2006 Jun 17, 15:29 +0300
On 6/17/06, Bill <billyrem42@earthlink.net> wrote:
Tracking (just barely) so far. Given the mass of stone etc extending up 200
to 400 meters and predominant wind coming off the land, what happens to the
tops of 430 meter buildings in your scenario?. BTW, Franks height of eye
was closer to 4 meters.
Bill, to calculate the dip for 4m just multiply the values for 10m by 2/3 corresponding approx. to the square root of 4/10. Please note that the dip provided is related to a true horizon (at sea level) and not to an artificial horizon of a shoreline. It wasn't my intention to calculate the observed situation. I just wanted to give an idea on the effects of a strong inversion (before ducting starts). Once ducting starts things become even "worse". The following Web pages from Andy Young may give an idea on this
and here his beautiful simulations
or the link he provides on his page to those real observations
Marcel
