Hands-on Activity: GPS Art

Contributed by: Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

An aerial photograph of a corn field shows a map of the United States, the words "God Bless America," and mazes on the outer edges of the field that have been cut into the field. The design was "mapped out" using inexpensive software, and a farmer then plowed the field accordingly using data loaded in a GPS receiver.
Figure 1. GPS Art.
copyright
Copyright © http://ion.org/newsletter/, Volume 12, Number 4 (Winter 2002-2003).

Summary

Students design their own logo or picture and use a handheld GPS receiver to map it out. They write out a word or graphic on a field or playground, walk the path, and log GPS data. The results display their "art" on their GPS receiver screen.

Engineering Connection

Engineers design GPS technology for many applications. In industry, GPS has uses in agriculture, surveying, map making from aerial photographs, public safety and telecommunications. GPS is used in recreation, sports and transportation on land, water, air and space. Science provides a wide range of applications: archaeology, atmospheric science, environmental, geology, oceanography and wildlife. In some cases, tiny transponders and transmitters are applied to birds, animals, products, shipments and measurement devices to collect data such as location, movement, altitude/depth and speed.

Learning Objectives

After this activity, students should be able to:

  • Use geometry and scaling in order to draw a sketch
  • Use numbers to count, measure, label, and indicate distances and points on a GPS receiver
  • Measure and calculate values from acquired data
  • Understand how technology is needed to explore space

More Curriculum Like This

GPS on the Move

During a scavenger hunt and an art project, students learn how to use a handheld GPS receiver for personal navigation.

Middle School Lesson
Where Is Here?

In this lesson, students are shown the very basics of navigation. The concepts of relative and absolute location, latitude, longitude and cardinal directions are discussed, as well as the use and principles of a map and compass.

Middle School Lesson
Gathering Global Data: Mind Bending GPS Occultations

Students learn about the remote sensing radio occultation technique and how engineers use it with GPS satellites to monitor and study the Earth's atmospheric activity.

Navigating at the Speed of Satellites

In this lesson, students investigate the fundamental concepts of GPS technology — trilateration and using the speed of light to calculate distances.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

  • Solve problems involving scale drawings of geometric figures, including computing actual lengths and areas from a scale drawing and reproducing a scale drawing at a different scale. (Grade 7) Details... View more aligned curriculum... Do you agree with this alignment?
  • Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.). Copying a segment; copying an angle; bisecting a segment; bisecting an angle; constructing perpendicular lines, including the perpendicular bisector of a line segment; and constructing a line parallel to a given line through a point not on the line. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Information and communication systems allow information to be transferred from human to human, human to machine, and machine to human. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • Solve problems involving scale drawings of geometric figures, including computing actual lengths and areas from a scale drawing and reproducing a scale drawing at a different scale. (Grade 7) Details... View more aligned curriculum... Do you agree with this alignment?
Suggest an alignment not listed above

Materials List

Each group should have:

  • GPS Receiver
  • 2 copies of the GPS Art Worksheet (one for each group member)

Introduction/Motivation

The global positional satellite system (GPS) has some very serious uses, such as for navigating ships at sea, airplane landing systems, and search and rescue operations. However, GPS can also be used for fun activities and recreational purposes. For example, have you ever been physically challenged by a maze that has been cut into a corn field? Did you ever wonder how that corn maze was created? Well, today farmers and recreational clubs can use GPS to design and plow mazes into fields. Figure 1 shows an actual corn maze that was designed using GPS and inexpensive software. To design the maze, a GPS engineer made an image of the desired picture using mapping software to produce a set of coordinates which would connect to form a picture — kind of like connecting the dots. These coordinates were then downloaded into driving instructions on the farmer's tractor-mounted GPS receiver. The farmer plowed the maze — that is, connected the dots — following the GPS instructions. Amazing! This activity will show you how to create your own GPS art and have fun while learning more about the global positioning satellite system.

Procedure

Background

The Global Positioning System is a constellation (or set) of at least 24 satellites that continuously transmit faint radio signals toward the earth. These radio signals carry information about the location of the satellite and special codes that allow someone with a GPS receiver to measure distance to the satellite. Combining the distances and satellite locations, the receiver can find its latitude, longitude, and height. GPS satellite signals are free and available for anyone to use. GPS technology is becoming very popular in cars and buses, sporting goods, cell phones, and many other commercial and professional products.

GPS receivers have a permanent memory that remembers its position from the last time that it was turned on, the time, and an almanac of the locations (actually orbits) of the GPS satellites. If your receiver was used relatively recently in a location not too far away, this information will be valid. So, when the receiver is turned on, it will begin looking for the satellites that should be visible at the current time at your location. Once it acquires four satellites, it will begin showing your current location and the current time. At this point, it will show an indication that it is in 3-D navigation mode. The time it takes to get to 3-D navigation will typically be less than one minute, but it can sometimes take a bit longer, especially if you are not out in an open area.

When the receiver is first turned on, it will display some type of satellite visibility page. The Satellite Page shows the satellites that the receiver thinks are currently visible from your location. The GPS constellation of satellites will always have a total of at least 24 satellites; sometimes there are as many as 28 operating at the same time. This means that from any point on earth, there should be at least four available in the sky above you at all times. The GPS satellites travel in orbits around the earth, each with a period of 11 hours and 58 minutes. So depending on the time of day you go outside, your receiver will see different satellites overhead. The same satellites will appear each day but their pattern in the sky will shift four minutes earlier each day. When a new satellite is launched or an old satellite is turned off, the receiver will be notified as soon as it tracks one of the other satellites in the constellation.

Each GPS satellite has a unique number that identifies it, sometimes called a PRN (pseudo random noise code number). The satellite number is shown on the bullseye plot (an actual bullseye-looking diagram in the center of the receiver's screen) and on the bottom of the screen. The bullseye represents the sky above you. Satellites shown in the center are directly overhead, and satellites shown near the outermost ring are near the horizon. North is typically at the top of the screen.

Before the Activity

  • Make enough copies of the accompanying worksheet so that each student has one.
  • Set up all the GPS receivers to the default or common settings. You will need to:
  1. Clear the current track
  2. Set the Units to the factory default or to another common setting that you prefer.
  3. Set the time on all receivers to show either local time or UTC time (Greenwich).

With the Students

  1. Get the discussion going with a question. Ask the students to estimate the largest size letters that a person could write their name (in the sand, for example, or in corn field)? How would they do it? What objects would they use?
  2. Pass out the worksheet for students to use with the activity. To tie into geometry concepts, assign students different types of triangles — acute, right or obtuse — that they have to trace with their GPS receiver in the space indicated on the worksheet. They should keep it simple (straight lines are much easier to follow than curves).
  3. Students should then orient their paper in the direction of either an open field or playground where the activity will be conducted. They should determine the heading or direction of each line segment in their picture.
  4. Have students pick a scale to map their picture to a distance they will walk in the field. Think about how big it has to be for the handheld GPS to be accurate enough to use. They may have to try a couple of different line lengths to determine what works best.
  5. Students should start at the beginning of their picture and mark the starting waypoint.
  6. Tell them to head in the direction indicated by their picture for the distance they want. They should enter additional waypoints at each turn, mapping out their picture.
  7. Tell the students that when they are done, they should be able to see their picture on the receiver's map display. Have them critique their picture: how does it look? How well do the edges and corners meet?
  8. Ask the student to put their waypoints together in a route and try to retrace their picture. Did it work?
  9. After the activity, run the post-activity voting assessment with the students as described in the Assessment / Evaluation section.

Attachments

Safety Issues

Ask students to be very careful with the GPS receivers so as not to cause any damage (especially if they are borrowed!). Remind them to stay in their groups and not to stray too far from their class; they are still novice GPS users!

Troubleshooting Tips

Make sure to have spare batteries as the receivers may use them up quickly.

Have students draw simple letters first, like an "H" or "E."

Students should use the GOTO function to get them back to an intersection.

For best results, students should make their picture large. If it is too small, the errors in GPS will be very noticeable, and they might not get a legible picture.

It is important that students do NOT lift up their pencil or pen while drawing their picture, as GPS receivers continuously track the image path, so the path cannot be broken in their picture.

Assessment

Pre-Activity Assessment

Prediction/Question: Ask the students to predict:

  • Ask the students to predict the largest size letters that a person could write their name (in the sand, for example, or in corn field)? How would they do it? What objects would they use?

Activity Embedded Assessment

Worksheet: Have the students complete the activity worksheet; if time permits, review their answers to gauge their mastery of the subject.

Post-Activity Assessment

Problem Solving: Have the students engage in open discussion to suggest solutions to questions/problems.

  • What scale did students use to map their picture? Was the scale large or small? Why?

Contributors

Matt Lundberg; Penny Axelrad; Janet Yowell; Malinda Schaefer Zarske

Copyright

© 2004 by Regents of the University of Colorado.

Supporting Program

Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under a grant from the Satellite Division of the Institute of Navigation (www.ion.org) and National Science Foundation GK-12 grant no. 0338326. 

Last modified: August 10, 2017

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