CoAuthors

Justus Leben (Colorado Center for Astrodynamics Research, USA); Ben Hamlington (Old Dominion University, USA)

Classroom demonstrations of nadir and Synthetic Aperture Radar (SAR) altimetry are described that are suitable for outreach demonstrations to the general public and classroom instruction for high school students. Nadir altimetry is introduced using an ultrasonic rangefinder and a programmable microcontroller. The rangefinder incorporates a simple ultrasonic sensor with a microcontroller. The sensor sends out a burst of ultrasound and then listens for the echo when it bounces off an object. The working range of this rangefinder is between 2 centimeters and 3 meters. The microcontroller is connected to a laptop, and the data from the sensor can be read into MATLAB for data visualization and analysis. This inexpensive rangefinder can be used for a variety of simple experiments, such as making range measurement of students walking towards and away from the sensor. A more advanced experiment is described to explore the difference between melting sea ice and melting continental ice in terms of their contribution to sea level change. SAR imaging/altimetry is demonstrated using a short-range "coffee can" radar kit. Sample SAR images and range measurements collected using this system are shown and outreach/education demonstration experiments using the system will be described.