[BC] Lat Long question (Answered)

[RichardBJohnson at comcast.net]

They are not far off from each other for practical
purposes, but if you want to make a FCC filing,
some corrections should occur. Here's the Hammet
and Edison paper on the subject.

http://www.h-e.com/pdfs/de_sbe94.pdf

Note that most of the surveying in the Northeast
is awful (read wrong). There are whole towns
that are not where they purport to be. In fact,
computerization of property boundaries in the
80's disclosed that there is about twice as
much property (area) owned as actually exists!
When you hire a surveyor to survey some land,
they try to reconstruct the original boundaries
and replace the words with geographical
coordinates. It isn't easy!

Even the GPS coordinates need to be
"corrected" because they assume a spherical
earth with its center of gravity in its center,
when, in fact it is pear-shaped, with the CG
displaced off towards the Andes Mountains!

So, unless you are making a FCC filing,
Google-Earth is close enough with the
maximum error being 1.3 seconds in
latitude and 4.4 seconds in longitude.
Move the Google Cursor see how small
a distance that is!

--
Cheers,
Richard B. Johnson
Read about my book
http://www.LymanSchool.org


 -------------- Original message ----------------------
From: "Ronald J. Dot'o Sr." <ron.doto at comcast.net>
> It appears that Google Earth uses NAD 83.
> 
> Ron D
> 
> 
> ----- Original Message ----- 
> From: "Ronald J. Dot'o Sr." <ron.doto at comcast.net>
> 
> 
> >I know that the FCC uses NAD 27 on their applications.  Does anyone 
> >know which NAD Google Earth and M$ Virtual Earth use when you run the 
> >curser over a specific point to get a Lat Long readout?
> >
> > Ron D
>