Subject: margins of error
Date: Feb 06, 2001 @ 05:22
Author: Michael Donner ("Michael Donner" <m@...>)
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marathon again
for possibly the first reported multi library day in history
 
& if anyone was wondering
it is not possible to do a quintilibrary day at all on a monday in monroe county because big pine is closed on mondays
moreover the feat would be much easier to accomplish traveling up from key west than down from key largo
for causes previously mentioned
 
but about the glhemaokpa error margins plural
  since there were actually at least 5 of these also
 
the first
& most disturbing & possibly largest one concerns the reliability of the usgs topo again
  yes jack it is idmtwy deja vu all over again
but i am inclined to trust them here yet again
even after having been bamboozled by them there
because the exercise of pinpointing the quintipoint just where they did was in this case so comparatively simply & straightforward
 
since the point is defined as a certain public land survey corner corresponding to a projection westward & northward of the north & west boundaries of palm beach county to a rectilinear corner junction within the lake
& since i could find no evidence that the lake itself has ever been surveyed
it would seem to follow that the latitude of the quintipoint would be absolutely determined by the latitude of the palm beach county north boundary where it enters the lake just south of port mayaca
& that its longitude would be absolutely determined by the longitude of the palm beach county west boundary where it enters the lake just east of clewiston
 
& the truth is that i didnt really do all my homework here
  tho i meant to & then forgot
which includes double checking these coordinates on the important correlative quads
namely port mayaca & clewiston west
even while i am pretty sure there has been no screw up
 
second
it really is not possible to define the point from usgs topos down to anything more precise than whole seconds of lat & long
tho i tried foolishly to determine them down to hundredths of a second
 
that is
the honest target area was only about a 100 foot square rather than a 1 foot square
 
third
a gps gives only a high probability of being correct within about a 30 foot radius
 
fourth
our 2 gps receivers were not fully synchronized & actually disagreed in the end by a couple hundred feet i believe
tho i was trusting & going with bills more than toms
since tom couldnt even say which nad he was using
& was probably using
 
must stop
m


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