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Archiver > TMG > 2011-02 > 1297697352


From: "John Cardinal" <>
Subject: Re: [TMG] Latitude and Longitude Conversion
Date: Mon, 14 Feb 2011 10:29:12 -0500
In-Reply-To: <1544844003.20110213231219@comcast.net>


Eric Haas wrote:
> At 41° N, one second of longitude is about 20m, and one second of
> latitude is about 30m. Using decimal degrees, a change of one in the
> fifth place after the decimal point is about 1/3 of that.

Eric,

What's your point?

The specific example led to a small loss because the original address was
close to an integer degrees-minutes-seconds location. For other values, more
precision is lost. See the example in the SS help pages where storing the
location of the pitcher's mound at Fenway Park resulted in a location near
the dugout approximately* 80ft away. 80ft could mean a lot of searching in a
cemetery.

http://ss.johncardinal.com/usermap.htm#coordinates

John

P.S. I didn't do the math to workout the exact difference between the two
point. I estimated 80ft based on the map scale.



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