GPS Basics (PCEC)

Summary:

The global positioning system (GPS) is an orbiting satellite-based system that determines the position of a GPS receiver in three dimensions, anywhere on or above the Earth, 24 hours a day. Currently, the U.S. Government allows the public to receive signals from 24 GPS orbiting satellites. They are aligned from the horizon to straight overhead.

Grade Level:

7 and up

Recommended Setting:

Indoor and outdoor classroom

Outdoor Activity:

No

Location:

Potlatch Conservation Education Center at Cook’s Lake, Casscoe

Contact:

Education Program Coordinator, 870-241-3373

Duration:

3 hours

Suggested Number of Participants:

20 - 25

Special Conditions:

One adult supervisor per 10 students; outdoor activities—weather-permitting.

Objectives:

  • Learn how to use a GPS unit in the classroom before applying it outdoors.
  • Use the unit in a field exercise.

Key Terms*:

Bearing

Course

Current destination

Final destination

Heading

Location (lat/lon)

Location (selected)

Pointer

To course

*See glossary for definations

Materials:

GPS unit with fresh batteries

Student GPS handbook

Background:

Knowing how to use a compass leads to an easier understanding of GPS. Imaginary lines divide the Earth, circling east to west and north to south. Those circling the Earth from east to west are called latitude while those ranging from the North Pole to the South Pole are called longitude. These will be the coordinates for marking or finding a position.

Procedure:

  1. Introduce latitude and longitude, how they are read and where they begin and end.
  2. Hand out GPS units to participants.  Instruct them on the safe handling procedures.  Give detailed instruction on the unit’s functions and controls.  Provide a handbook with written instructions for later reference in the field.
  3. After discussing the practical applications in the classroom, participants will go outside and use their GPS to find pre-located positions at Cook’s Lake.

Modifications:

After returning to school, participants can use their new GPS knowledge to map out practice courses on campus. This could include hiding geocaches and having other participants locate them. (Adapted from Arkansas Game and Fish Commission GIS “GPS Basics.”)

Review:

  • Upon what system is the GPS based?
  • What is the system of coordinates used with the GPS?
  • When using a GPS unit, what are two things important to carry with you?

Resources:

Outdoor Guide to Using Your GPS, Steve Featherstone, www.creativepub.com

Glossary:

Bearing – the horizontal direction of one point with respect to another or to a compass; direction of a fixed point or the path of a moving object from a point of observation

Course – path or direction of travel

Current destination – place set for the end of a journey or where something is sent; place or point aimed at

Final destination – in orienteering, desired ending location of the compass or GPS user

Heading – in orienteering, the direction selected when using a compass or GPS

Location (lat/lon) – point in physical space that something occupies on Earth's surface; also the siting or positioning of something

Location (selected) – a position or point in physical space that something occupies on Earth's surface; also the siting or positioning of something

Pointer (GPS) – directional arrow on a GPS compass screen that shows the travel direction when locating a previously marked position

To course – develop a travel course to reach a destination using compass points and/or GPS lat/long readings