Egypt Primary 6 Communication Technology, Week 9: Sensors that work from far away

Sensors and safe gaming

Week 9 · Theme 2 Digital Safety and Security Precautions, Lessons 1–2 Explorer in Action; How to Deal with Electronic Games · 3 lessons

Sensors that work from far away

ICT P6 Term 1, Theme 2: pp. 44–53

GoalExplain remote sensing with three examples and say how explorers protect their work.

New words

remote sensing · learning about something without touching itsensor · a device that detects something and turns it into numbers or picturesmachine learning · a way for computers to learn patterns from examplesback-up · an extra copy of your files kept safe in another place

Explanation

Remote sensing means getting information about something without touching it. This is useful when a place is dangerous or impossible to reach. A sensor sends out or receives waves and changes them into numbers or pictures. Infrared pictures can help find shapes under the ground. Radar sends radio waves to measure the speed of cars. Sonar sends a sound into the sea and listens for the echo, to find fish and to map the sea floor. An explorer who studies the past can use satellite pictures, a global positioning system (GPS) and maps of the Earth to look for old shores and old villages. Remember machine learning from Week 3: the explorer shows a computer places where old villages are known, and the computer learns to spot similar places. Explorers also protect their work: they make back-ups, use strong passwords and security software, name their sources, and ask permission before they publish pictures.

Sensor	What it does	Example
infrared	shows shapes below the ground	old walls under a field
radar	measures speed with radio waves	the speed of cars on a road
sonar	uses sound echoes under water	finding fish and mapping the sea floor

Worked examples

boat sends sound→sound hits the sea floor→echo comes back→depth is worked out

A fishing boat sends a sound into the sea. The sound hits the bottom and comes back. The longer the echo takes, the deeper the sea. The boat now knows the depth without touching the floor.

A police radar measures how fast a car drives past. The radar never touches the car. It sends radio waves and reads what comes back.

An explorer gives a computer 50 pictures of places where old villages are known. The computer finds a pattern in them. Then it looks at new pictures and marks 3 places that look similar. People check them.

Class activity

Echo game. With a grown-up in a safe, quiet hall, clap once and listen for the echo. Do it near a wall and then in the middle of the room. Which echo comes back sooner? Draw the two situations with arrows for the sound. Explain how sonar uses the same idea.

Practice

What does ‘remote sensing’ mean?

Which sensor uses sound under water?

Look at the echo times. Which boat is over deeper water? Say the letter.

Boat	Echo takes
A	1 second
B	3 seconds

Name two ways explorers protect their work.