RADAR

RADAR is an activity developed by Learning Undefeated to help students explore wave properties through the lens of radars.

In this activity, students are introduced to radar and the Doppler effect as well as how it applies to plane detection and air traffic control. Students will use a constructed radar box to model the data collected by radar systems. Students will use the provided equipment to identify the object of a shape they cannot see by using the equipment to measure the distance to the object from a sensor. Students will also collect simulated data of an object in motion to see how the same equipment can relay information of not only distance but movement and direction as well. Students will see how this applies to the Department of Defense and understand the need for updated radar systems to detect fast-moving and low-flying vehicles.

Learning Objectives

Standards Alignments + Connections

Next Generation Science Standards Connections

HS-PS4-5. Communicate technical information about how some technological devices use the principles of wave behavior and wave interactions with matter to transmit and capture information and energy.

Texas Essential Knowledge and Skills Connections

PHYS.7.D. Investigate behaviors of waves, including reflection, refraction, diffraction, interference, resonance, and the Doppler effect

Virginia Science Standards of Learning Connections

PH.5C. Wave interactions are a part of everyday experiences

Activity Components

Pre-Laboratory Engagement

In the activity, students will build on concepts of wave properties as well as discuss how the how sound waves differ from waves on the electromagnetic spectrum.

Students should be familiar with the speed of sound and the speed of light as well as common examples along the electromagnetic spectrum.

Recommended Activities/ Resources

Wave Properties

Electromagnetic Spectrum

Conversation Starters:

What information can be sent over waves?
What kind of waves do common technology (WiFi, cellular calls, etc) use?

Activity

At any given moment there are about 5,000 commercial airplanes in the sky over the United States. Those who live close to an airport may see some of these planes, but many fly above clouds and beyond our field of vision. Air traffic controllers, ATCs, based in traffic control centers and at each airport have the responsibility of directing planes from an area of up to 200 miles wide to ensure that our crowded airspace does not result in crashes. So how do the ATCs keep track of all the planes, ensuring minimum distances between each, without being able to see hundreds of miles away? Radar!

Radar, which stands for radio detection and ranging, uses electromagnetic waves to “see” what the eye cannot. The electromagnetic waves, usually radio or microwaves, sent by a transmitter near the control center are reflected by metallic objects, water, and landforms. A receiver and processor then measure the reflected wave to determine an object’s location and speed. Because all electromagnetic waves, radio or microwave, travel at a constant speed, by measuring the time it takes for a signal to return, the distance of the object can be measured.

To measure the speed of an object, radar often depends on the Doppler effect. This effect is the difference between the observed frequency and the emitted frequency of a wave. By measuring the received wave that bounced off of an object and comparing it to the emitted wave that the transmitter sent, we can determine how fast an object is moving and in which direction, or its velocity.

Radar has applications outside of air traffic as well. Doppler radar can also detect water, making it an essential tool for meteorologists to see coming storm systems and to track their strength. Variations like SONAR, which uses sound, and LIDAR, which uses high-frequency light, have been used to better detect the ocean floor, forest canopies, and more.

To build the modeled radar system used in this activity, use the following files to construct one.

Assembly Guide
Radar Box Files
- Requires 3D printer and lasercutter

Post-Laboratory Extension

After this lesson, we recommend continuing the conversation about hypersonic vehicles and the challenge to detect them. The following activity uses hypersonics as a context to apply optics content.

Reflecting on Hypersonics

More Hypersonics curriculum from Air & Space STEM Outreach is available here.

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