Teaching Scouts How GPS Works

Step 2: Next, pretend to go to the parliament buildings from
your meeting place. Say the parliament buildings are at S2,
W1. Calculated from your meeting place location, the correct
answer should be down 7 (5+2) and over 4 (3+1).
Step 3: Ask them what would happen if the parliament buildings
were actually at S2.5 and W1.5. The answer would be 7.5
and 4.5 respectively. Congratulations; now they understand
how GPS works with all those numbers.
Step 4: You may notice that GPS uses three sets of numbers
(i.e. N45 16.944). The third sets are simply because the earth
is large and we need to go down to this level to determine
the exact location.
The Challenge
Show the Scouts Diagram #2 with the three GPS locations
marked on it, followed by the Google picture directly to the right.
Make sure they understand that the diagrams show the same
three locations, the one below right is simply a satellite picture.
Tell them to write down the following number N45 16.909
W 75 45.722. Using the numbers given to them from the three
locations in Diagram #2, navigate using addition and subtraction
to the point above. This is no different than going from N5
E3 to S2 W1 in our training earlier.
Ask them to put an “X” where they think the mystery location
is, and as you already know, it is the tree. After my Scouts
finished guessing I took my GPS and we walked to that location.
They ended up standing under the tree.
Take a Hike
Now that you know how it works, take them out for a geocaching
hike (three or four caches make a great six hour hike).
Treasure hunting makes it a little more fun than just hiking.
For more information on GPS hiking, go to the geocaching
website mentioned above.m
— Scouter Barry Gervais enjoys leading the 23rd Nepean Scouts
on geocaching hikes. Find another GPS article in the May 2008
issue of the Leader Magazine.
Diagram 2
(Google Map diagram)
(Satellite Map)
NOTE: A pdf version of
diagram 2 is available
for download at
www.scoutinglife.ca.
ScoutingLife.ca | October 2009 39