☰ Year plan · Communication Technology

Tools for exploring

Week 1 · Theme 1 The Role of ICT in Our Lives, Lesson 1 Explorer in Action · 3 lessons
2

GPS, radar and hidden things

ICT P4 Term 1, Theme 1: pp. 8–13
GoalExplain what GPS, a magnetometer and ground-penetrating radar find.
New words
GPS · a way to find where something is, using satellitesmagnetometer · a tool that notices metal under the groundradar · a tool that sends signals and listens for them to bounce backburied · hidden under the ground
Explanation

Once explorers know the area, they need three more helpers. GPS uses satellites to tell you where a place is, like a dot on a map. A magnetometer notices metal that is buried, because metal changes the magnetic field around it. Ground-penetrating radar works like an echo. If you shout in a big empty hall, the sound bounces back to you. Radar sends a signal down into the ground and listens for the signal to bounce back from buried things. The echo tells the explorer that something is down there, even before anyone digs.

ToolWhat it doesAbove or below ground?
GPSfinds a placeabove ground
Magnetometernotices buried metalbelow ground
Ground-penetrating radarfinds buried objectsbelow ground
Worked examples
signalsphonemap
Karim’s family drives to a village they do not know. A phone with GPS shows a blue dot for their car on a map. The satellites help the phone work out where the car is.
signal goes downburied objectecho comes back
Omar claps in a big empty hall and hears the echo come back. Radar does the same under the ground: it sends a signal, waits, and the echo shows that something solid is buried.
metal✓metal✓cloth✗wood✗
A magnetometer notices metal, but not cloth or wood. Under a sandy playground it would notice a metal key and a coin. It would not notice a teddy or a log.
Class activity

Echo and treasure. Part 1: with a grown-up nearby, clap once in a big room, then once in a small room. Which room gives the bigger echo? Part 2: on paper, draw a map of a room. Mark a hidden treasure with an X. Write three clues for a partner, such as “from the door, walk five steps to the window”. Does your partner find the X?

Practice
1
Which tool notices metal under the ground?
2
Radar sends a signal down and listens. What does the echo that comes back tell the explorer?
3
What does GPS use to find a place?
4
Look at the picture. Which things would a magnetometer notice? Say the letters.
ABCD