Pinpointing Location with GPS Demonstration

Shelley Olds (UNAVCO), Daniel Zietlow (UNAVCO), & David Thesenga (Alexander Dawson School)

This activity is part of the On the Cutting Edge Exemplary Teaching Activities collection

This activity was selected for the On the Cutting Edge Exemplary Teaching Collection

Resources in this top level collection a) must have scored Exemplary or Very Good in all five review categories, and must also rate as “Exemplary” in at least three of the five categories. The five categories included in the peer review process are

Scientific Accuracy
Alignment of Learning Goals, Activities, and Assessments
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This page first made public: Feb 27, 2022

Summary

Using string, bubble gum, and a model of a GPS station, demonstrate how GPS work to pinpoint a location on Earth.

Precisely knowing a location on Earth is useful because our Earth's surface is constantly changing from earthquakes, volcanic eruptions, tectonic plate motion, landslides, and more. Thus, scientists can use positions determined with GPS to study all these Earth processes.

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Context

Audience

This demonstration can be used as an extension to an introductory earth science course.

Skills and concepts that students must have mastered

Students should have a general understanding of GPS.

How the activity is situated in the course

This demonstration can be used at any time in an earth science class, though is particularly useful when discussing how GPS works. This activity needs 5- 15minutes, depending on questions and extensions into an activity about GPS.

Goals

Content/concepts goals for this activity

GPS satellites send a signal with important information that can be used by GPS receivers on the ground.
How long a signal takes to reach a GPS receiver tells us distance between a satellite and GPS.
Measuring position in this way is called trilateration.
We need four satellites to find and pinpoint the precise position.

Higher order thinking skills goals for this activity

Interpret the intersection of spheres in 3-dimensions.

Other skills goals for this activity

Description and Teaching Materials

Pinpointing Location with GPS Demonstration Writeup (Acrobat (PDF) 50kB Nov12 21)

Teaching Notes and Tips

A complete video of the demonstration can be found on the UNAVCO YouTube Channel.

Assessment

Students describe and sketch what have they learned from the demonstration.

The exercise includes sample questions the learner could answer. These can be used for formative assessment of understanding or they can be graded on a simple 2-point scale:

2 points = correct answer with thorough supporting evidence and/or complete description
1 point = answer not completely correct or lacking thorough supporting evidence or description
0 points = incorrect answer