Lab Name Properties of waves, using experiment allowing the visualization of Analog AM and FM wave signals.
Subject Area Science
Grade 8
Topic Waves
Experiment Title Visualization of analogue AM and FM wave signals showing the frequency and amplitude.
Hardware Linux machines (ex laptop, raspberry pi) and 2 Software Defined Radios (ADALM Pluto).
Software GNU Radio, COSMOS toolkit framework.
Number of Sessions to teach the topic 1-2 sessions
Educational standards to be addressed
  • MS-PS4-3
    Integrate qualitative scientific and technical information to support the claim that digitized signals are a more reliable way to encode and transmit information than analog signals.
COSMOS concepts to be used for the lab Wireless signals, visualization of analogue AM and FM wave signals on the computer screen, relationship between the two, frequency and amplitude.
K12 Educational Goals (How the educational goals are achieved through teaching using the experiment, how the topic is connected to the COSMOS concepts used) Teaching the properties of waves by visualizing analog AM and FM wave signals on the computer screen and observing the difference between the two, frequency and amplitude.
Short Description and Walk-through of the experiment
  1. Teacher will use a short slide-show to introduce & explain the topic of waves, the different types of waves & the properties of waves.
  2. Materials & equipment are set up on student's desks.
  3. Activity:
    1. Students will observe (visualize) and listen to the analog sound being played using amplitude modulation AM and record their observations.
    2. Students will observe (visualize) the analogue sound being played using frequency modulation FM and record their observations.
    3. Students will then compare & contrast the two.
After all students complete their handouts there will be a share out with observations and comments.
Testbed mapping of the experiment The experiment can be extended by executing it into a testbed (ORBIT/COSMOS) through the following steps:
We can configure a particular node to transmit an analog AM signal and another to transmit an analog FM signal and display the information showing the wave form and spectrogram. So, we perform the experiment using nodes on the testbed and we can visualize the wave signals on the computer screen. From this visualization we can observe the relationship between the two.

Experiment Execution

Select a modulation scheme (AM or FM) and press START to begin the experiment. In order to terminate the experiment press STOP.

AM Modulation FM Modulation

Experiment Material

NGSS Lesson Plan
Worksheet
Presentation

© 2018 COSMOS Project. Created by Richard Foster, Parkside Preparatory Academy MS2 Brooklyn, New York