Infrasound Detector

Building an Infrasonic Source for Simulating 'Venus-quakes'

When: August 2020 Where: VN Instruments (for AGU conference)

My first exposure to fast science and prototyping. The breakneck pace at which we wrote code, assembled transducers and performed tests on our newly-built system was exhilarating.

The Project

We were asked if it was possible for our ultrasonic transducers to detect low-frequency oscillations in wind speed. The application? To study how the dense atmosphere on Venus changed in response to a seismic event.

Testing system with a) subwoofer b) transducers c) SIA (ultrasonic testing unit) and the TIVA (MCU used to drive the subwoofer)

Time domain time of flight (20 Hz, amplitude 1) data. Graph on right shows transducers off-axis (cannot see the infrasound wave). Graph on the right is the result with transducers on-axis - we can see the sinusoidal nature of the superimposed infrasonic wave.

Building the source

I wrote embedded code for a TIVA MCU and DAC system to drive an off-the-shelf subwoofer at various frequencies. This was our infrasound source.

Analyzing the FFT Data

We acquired signal data using our ultrasonic system. Then, I used signal processing algorithms to improve SNR and identify sound pressure levels as a function of source frequency (above).

AGU Presentation

I designed a poster and presented our findings (remotely) at the 2020 AGU conference: https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/705097

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