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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Position from a Clock with Photo Diode
From: Peter Fogg
Date: 2005 Jun 7, 08:00 +1000
From: Peter Fogg
Date: 2005 Jun 7, 08:00 +1000
> From: Brooke Clarke > > Suppose that a clock that keeps UTC time to within 1 second has a photo > sensor with an analog output to a computer. The clock is indoors but > the room has a window to the outside so although the clock is in the > shadow of the Sun it does see a daily brightness curve. > > How accurately can the clock determine where it is in the world? > It will have a hard time working out its longitude. As to latitude, presuming the variance due to weather can de discounted, could the question be reformulated as: how accurately can the principle of an annalemma be used for determining latitude? Or another variation, could the times of sunrise and sunset be used over a period to determine latitude? As you may have noticed, these aren't so much answers as more questions. The general idea sounds plausible.
