Hi,
On 11/13/2017 06:32 PM, Gregory Beat wrote:
I grew up east of the Iowa/Missouri border, so this boundary dispute was
well-known ... and occurred at same time Joseph Smith (Mormons) was at Nauvoo,
IL (1839-1844).
In 2006, the Iowa-Missouri border was investigated with GPS, as much an archeology
project as locating the historic Sullivan & Brown survey markers.
http://www.theamericansurveyor.com/PDF/TheAmericanSurveyor_MO-IABoundaryLineInvestigation_Mar-Apr2006.pdf
Iowa-Missouri Border War (1826-1849)
http://iagenweb.org/history/soi/soi32.htm
NOAA’s : National Geodetic Survey (NGS) made news in 2009 when media reported
that the Four Corners monument was in wrong place (by 2.5 miles).
Deseret News
https://www.deseretnews.com/article/705299160/Four-Corners-Monument-is-indeed-off-mark.html
NOAA statement and clarification
https://www.ngs.noaa.gov/INFO/fourcorners.shtml
==
I’m in France and I don’t think that any borders in Europe were defined by
astronomical observation, but in the US I believe that at least some of the
state borders were thus fixed. As a second’s error in time will be about a
nautical mile in US latitudes, I wonder if anyone has measured with GPS, how
good the original surveys were?
There is a lovely article about the Dixon-Mason line and how they now
used GPS to measure it accurately. Turns out that Dixon-Mason measured
wrong, but not because they where hacks, they did it very accuratly with
the tools they had, but the mercury of their star-scope was not
completely flat due to gravitational pull from mountains, so when
correcting for that with now known data, they are very accurate with
what they had.
I think there was a thread about it some time back, but you should be
able to find it knowing what o search for.
I learned about what the whole issue was about from start.
Cheers,
Magnus
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