|
|
|
|
|||||
|
||||||
Subject: Re: milli-radian
From: Paul Hirose (paulhirose@XXX.XXX)
Date: Wed Mar 12 2003 - 22:52:52 EST
"Royer, Doug" wrote:
>
> On to the UTM projection.UTM's have Northing and Easting coordinates.Each
> section of the globe has differant East + West and North + South letters
> designating the desired area to use as a prefix to the Northing and Easting
> coordinates.Grids are marked as 1,000 meter boxes.Resolution is as follows.
> 6 digit Northing and Easting coordinates = 100 meter accuracy
> 8 digit coordinates = 10 meter accuracy
> 10 digit coordinates = 1 meter accuracy
That sounds like MGRS (military grid reference system), not UTM. For
example the Statue of Liberty is at MGRS coordinates 18TWL 807 047 (to
100 m precision) and at UTM coordinates +18 580700 4504700.
MGRS uses the universal transverse Mercator grid; it's basically an
alternate notation for UTM.
The only letter in UTM is the one for latitudinal zone. These zones
are 8 deg high. I'm between 32N and 40N, which puts me in zone S. But
if you know which hemisphere you're in (N or S), the letter is
redundant so is often omitted. My GPS receivers don't even display it.
MGRS is described in the U.S. Army field manual on land navigation:
http://155.217.58.58/cgi-bin/atdl.dll/fm/3-25.26/toc.htm
This manual also defines the mil.
|