Make sure that everyone is using the same datum.
Common datums include NAD27 CONUS, NAD83 and WGS80. Make sure
everyone is using the same datum that is marked on your map.
To check the datum on a U.S. Geological Survey map, look in
the lower-left corner.
sure that everyone is using the correct UTM zone.
Otherwise, your position will be about 350 miles
off. This is usually not a problem unless someone is using a
GPS that was previously used in a different state.
your map and interpolator
any position on your map.
which 1000 meter grid your mark is in. Ours is in 524000, 3747000. Note that the Easting
number is always read first, then the Northing. Also note
that two digits are large and the rest are small. This makes
it easier to read.
lay your interpolator
over your map.
which 100 meter square your mark is in. Add that to your
coordinates from step 3. Ours is in 524200, 3747300.
6. For an
little more accuracy, you can estimate the position within
the square to the nearest 10 meters. For example: our mark
appears to be halfway past the 100 meter markers. The result
would be 524250, 3747350.
you probably won't read the entire UTM position, remember
that when you are recording your information for later use,
it is not complete without the grid and datum. Our final
coordinate is 11S 524250, 3747350 NAD27 CONUS.
It looks confusing but, as you just learned, it's rather
simple. You may have noticed that many of our mission
contain the UTM information in this format.
There is a way of reading UTM in a short format. In order the
lessen the chance of mistakes being made by tired rescue
members, RMRU does not use this format. It also
rounds your position off to the nearest 100 meters, which is
usually not accurate enough for rescue work. However, you may
find someone who does and would like to know what they are
the UTM coordinate simply take the middle three digits of
each number and combine them. You must realize that there is
actually a zero in front of the Easting. Our coordinate of 0524250, 3747350 becomes 242473. I guess some people
found the UTM too simple and wanted to make it more