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Part
1: Using a GPS receiver to determine track
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Go
to an unobstructed outside location and use your GPS receiver to acquire a
3-D Navigation status (lock onto at least four satellites) on the Satellite
Page. Without
using the GPS receiver, try to orient yourself due north (track 0°). Move to the Compass
Page (or Position Page).
Start walking straight ahead and note the track and compass readings on
your GPS receiver. Compare your approximation of due north to the compass.
Use this information to adjust your orientation, if necessary, to due
north.
| Note: The compass and
track will adjust after
walking several steps. |
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Move
to the Position Page. Facing
north, walk a straight path for 30 steps while observing the values for
the compass tape and track. Stop, turn 50° to the right, and continue walking for 30 steps,
noting the values for the compass
tape and track. Discuss how
the compass tape and track will change if you were to stop, make a 70° turn to the left from your current position, and
continue walking.
Part 2: Using a GPS receiver to walk the
perimeter of a square
| Directions to the teacher: Give each group of students enough space to
complete the following tasks without interfering with each other.
Also, use a marker to designate the starting point for each group. |
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Devise
a plan, using the GPS receiver, to walk the perimeter of a square with
side length of at least 50 steps, with your initial orientation due north.
This plan should include a labeled sketch of your proposed path, indicating
the vertices (including your starting point), the number of steps you plan
to walk for each side of the square, and the track at each vertex (see
Figure 1).
Figure
1.
Sketch of square path.
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Move
to the Map Page to clear your
map log and change your map setting to North
Up. Move to the Position Page, and at a designated starting point, use your plan and
the GPS receiver to walk your planned square, marking a waypoint
at each vertex (including your starting point) and noting your track
and trip along your route.
(Note: Trip will register once
you walk a tenth of a mile.)
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To
clear a map (clear a log):
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Move
to the Map Page and
arrow right to OPT.
Press Enter.
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Arrow
to Track Setup and
press Enter.
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Arrow
down to Clear Log and
press Enter.
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Arrow to Yes
and press Enter.
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To
make changes in the Map Setup:
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Move
to the Map Page and
arrow right to OPT.
Press Enter.
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Arrow
to Map Setup and press Enter.
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Arrow
down to Map: and press Enter.
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Use
the up arrow key to toggle to North
Up. Press Enter.
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Arrow
down to Route: and
press Enter.
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Toggle to Yes.
Press Enter.
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To
mark a waypoint:
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Move
to the Main Menu Page. Waypoint
should be highlighted. Press Enter.
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Arrow
to New and press Enter.
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Use
the Up Arrow and Right
Arrow to name your waypoint. Press Enter
to save the name.
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To
change the symbol, press Enter.
Select the desired symbol then press Enter.
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To
change the display, press Enter.
Toggle to Name with Symbol
then press Enter.
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Highlight
Done, and press Enter.
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Again, highlight Done, and press Enter.
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After
you have traversed your path, move to the Map
Page to see a map of your walked path. Evaluate your path by relating
your map to your track readings and walking actions. Explain any
discrepancies between your planned and walked paths. (Note: If a map does
not appear on the screen, change the map scale to 0.2 mi.)
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With
the class, share how your group completed this task, including how your
group used the GPS receiver readings to determine angle measurements.
Part 3: Using a GPS receiver to walk the
perimeter of an equilateral triangle
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Devise
a plan, using the GPS receiver, to walk the perimeter of an equilateral
triangle with side length of at least 50 steps. This plan should include a
labeled sketch of your proposed path indicating the vertices (including
your starting point), the number of steps you plan to walk for each side
of the triangle, and the track at each vertex (see Figure 2).
Figure
2.
Sketch of equilateral triangle path.
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Move
to the Map Page to clear your
map log and waypoints. Move to the Position
Page, and at a designated starting point, use your plan and the GPS
receiver to walk your equilateral triangle, marking a waypoint at each vertex (including your starting point) and noting
your track and trip along your route. After walking the first two sides of the
triangle, press GOTO on the receiver and select the waypoint marked
as your starting point. The GPS receiver will calculate the bearing (or
track) from your current position (third vertex) to your starting point.
Compare this reading to the last track in your plan.
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To
clear a waypoint:
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Move
to the Main Menu Page. Waypoint
should be highlighted. Press Enter.
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Arrow
to Delete and press Enter.
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Arrow to Yes
and press Enter.
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After
you have traversed your path, move to the Map
Page to see a map of your walked path. Evaluate your path by relating
your map to your track readings and walking actions. Explain any
discrepancies between your planned and walked paths.
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With
the class, share how your group completed this task, including how your
group used the GPS readings to determine angle measurements.
Part 4: Using a GPS receiver to walk the
perimeter of an isosceles triangle
Part 5: Using a GPS receiver to walk the
perimeter of a scalene triangle
| Note: The following task is appropriate for students
studying trigonometry. |
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Devise
a plan, using the GPS receiver, to walk a scalene triangle with the first
side measuring 50 steps north, the second side measuring 30 steps, and the
included angle measuring 120°
(see Figure 3).
| Hint: Students can use the formula sin(A-B) = sinA*cosB –
cosA*sinB to calculate the last track. |
Figure
3.
Sketch of scalene triangle path.
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Move
to the Map Page to clear your
map log and waypoints. Move to the Position
Page, and at a designated starting point, use your plan and the GPS
receiver to walk your scalene triangle, marking a waypoint at each vertex (including your starting point) and noting
your track and trip along your route.
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After
you have traversed your path, move to the Map
Page to see a map of your walked path. Evaluate your path by relating
your map to your track readings and walking actions. Explain any
discrepancies between your planned and walked paths.
Part 6: Using the GPS receiver to determine
walking speed
| Note: Students will need to apply the distance formula to
calculate how long, in time, they will need to walk. They can use the
clock displayed at the bottom of the Position
Page to note their start time and stop time. |
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To
Reset trip:
- On the Position
Page arrow down to distance displayed below the word TRIP. Press Enter. The
word Reset appears on
your screen. Press Enter
again.
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Revise
your plan, reset the trip, and
repeat the above task. Comment on your group’s accuracy.
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Devise
a plan, using the GPS receiver, to walk .1 mi. at an average speed of 3
mph while reaching the speed of 5 mph at some point during your
walk.
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Reset
the trip, and implement your
plan. Evaluate your implementation, and if necessary, discuss ways to
improve your plan.
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Reset
the trip, and implement and
evaluate your revised plan.
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Devise
a plan to walk a 100-step trip, walking the first 50 steps at 2 mph, with
a speed for the last 50 steps that will yield an average speed of 4 mph
for the entire trip.
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