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Multi-channel

A project log for sound-based weather station

Converts weather into microphone-vibrations that DSP on a small computer can resolve into weather data

Dave MerrettDave Merrett 04/07/2016 at 10:260 Comments

Now we're going to get into the complex details. For a given number of resonators, they need to be arranged to make it easy for the sound signal processor to differentiate wind speed, direction and temperature. It makes sense to use an equally-azimuthally-spaced set of resonators. In other words, make it just as hard to sense wind from one direction as compared to any other. If we assume the resonators respond to wind-excitation in a classical cardiod-like pattern, we can expect the response from each ( colour-identified) channel as per image below. This is a hyopthetical 3-channel system I simulated using MATLAB..

Based on this angular response, we can simulate what the frequency spectrum output from each resonater might look like for a given wind direction. Most resonators will also respond at harmonics of their fundamental frequency ( like in bottle demo below), so Ive added these into the spectrum. Plot below is an example of the response when wind slowly rotates around the sensor

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