Sonar based detection is commonly used in many areas. Starting with animals – bats and dolphins use sonar for navigation and hunting. People also use this technology in many areas like in car parking systems (parktronics), in robot navigation. High frequency ultrasound is used in medicine for visualization and anomaly detection. Ultrasound has very wide practical use as it is non-destructive way of seeing things that naked human eye can’t.
Today practically everyone can do simple experiments with ultrasonic modules that cost pennies. You can get modules that work in air that can be used for measuring distances and even for robot navigation that detect obstacles.
Jason, wanted to move things from air to water. As we know ware sonars are also intensively used in many areas like naval navigation or fishing. For his experiments he’s chosen Stellaris Launchpad microcontroller board which sends and listens to audio signals reflected for various obstacles and surfaces in water. He decided to construct chirp signals that were sent from piezoelectric buzzer. Signals were detected with mic and audio amplifier module. The rest work is done by algorithm which detect and visualizes the reflected image. He was able to reach up to 9 feet of effective range. Initial work gave confidence to push things further where he intends to build submersible transducer, increase transmitter power and work on algorithms.