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Digital High Sensitivity Infrasound Monitor - Real Geophysics Research on a budget

Infrasound Monitor Presentation Paper #1 Construction Instructions

Full documentation and software on the Downloads page above

I have been working on a new geophysics project for the past three years, a compact infrasound monitor based on a digital, i2c enabled diferential pressure sensor. I feel this is a beauty. Very open-ended with lots of opportunities for students of all levels - primary to postgrad - to redesign and test replacement components. This is also real science, in a little studied area. Well suited to networking in small or large areas. Oh - and cheap! see Blog (above) for current status. A paper has been published in IOP Phys Ed.

As examples of real data see Blog post for 27/7/2017 - Mean Acoustic Power - Sabic Gas Flare

or

Demonstrating f.f.t. wavelet transform of a helicopter trace the Blog post for 8/12/2019 -- Chopper!

This rig capable of resolving to better than 1 3-millionth of an atmosphere will cost less than £100 and provide plenty of valuable experience in computing, physics, electronics, and signal processing to a small team for a year or so.

Infrasound is a little studied area of geophysics/environmental science ripe for further investigation. The only U.K. detector I can find reference to is possibly one run by A.W.E. at Blacknest though precious little information is extant. A national network of school & college infrasound detectors could potentially generate useful scientific data as well as remarkable educational benefits.

Code and instructions may be downloaded here - link.

Rig Alpha: Loftspace - pitched tile roof wind-filter
Current InfraSound Plot
ΔP 0.01-10Hz - updates hourly (54.53°N 1.08°W +100m)
Current InfraSound Plot
Acoustic Power 0.01-10Hz - updates hourly (54.53°N 1.08°W +100m)
Current InfraSound Plot
Weekly Infrasound Acoustic Power 0.01-10Hz - updates hourly (54.53°N 1.08°W +100m)
Rig Beta

20/7/21 Rig Beta, mobile version equipped with a real time clock being used to investigate Infrasound levels in cars.

Rig Gamma: Outdoors - 15m porous hose on flat roof
Current InfraSound Plot
ΔP 0.01-10Hz - updates hourly (54.53°N 1.08°W +100m)
Current InfraSound Plot
Acoustic Power 0.01-10Hz - updates hourly (54.53°N 1.08°W +100m)
Current InfraSound Plot
Weekly Infrasound Acoustic Power 0.01-70Hz - updates hourly (54.53°N 1.08°W +100m)
Rig A: Archived plots ... Rig B: Archived plots .. Rig G: Archived plots

The above are simple daily data plots. These are generated on the fly by the Pi used to monitor the sensor, and should be used for quick observation of output. The idea being that the data be downloaded from the PI for more detailed analysis. I have written a general analysis tool in python for this - examples below and on the Blog page (above).

infrasound
v1 2018
infrasound monitor redcar beach
v2 - Redcar Beach 2019, purple usb powerbank, yellow Pi case, Orange sensor unit, black foam wind-filter
Police Helicopter Infrasound
Helicopter within 1km, foam block windfilter, 20 -> 30 min

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Current InfraSound Plot
Infrasound Monitor raw data Aug -11th 2017

Current InfraSound Plot
Infrasound Monitor 'demeaned' -dayplot Aug -11th 2017

Current InfraSound Plot
Infrasound Monitor acoustic power dayplot Aug -11th 2017

Current InfraSound Plot
Infrasound Monitor spectrum Aug -11th 2017