Archive for the ‘detection’ Category
The EM fountian bowl!
I’ve just got this photo from Øystein Lia, the project leader for the Electromagnetic Fountain at NLI Engineering. A retired parabol antenna dish stemming from Tryvann, Oslo, that will form the fountain bowl. It looks quite small, but is in fact 2.5m in diameter.
Listening to the Electrosmog detector
THIS page describes how to identify the sources of electromagnetic radiation as heard using the Electrosmog detector that I used in my field survey for the Electromagnetic Fountain, and gives sound sample examples of them (listed below).
– Background Hiss (MP3, 79 KB)
– GSM (MP3, 45 KB)
– DECT (MP3, 111 KB)
– TETRA (MP3, 77 KB)
– 3G (MP3, 104 KB)
– WiFi
(It also demonstrates how to extend the sensitivity of the sniffer.)
Sniffing in Stavanger – Little EMV sniffer
This EMV sniffer was put together by Erich Berger and Martin Howse during the Maxwell City Workshop I took part in at Atelier Nord in 2007. It is based on kit components that can be purchased here.
Sniffing in Stavanger – Zap Checker
Here’s a video of the Zap Checker detector in action where the Electromagnetic Fountain is planned to stand.
Frequency range: covers 1 MHz to 8 GHz.
Output: Audio Jack and needle display.
Antenna: Internal
Calibration: Can be calibrated for different signal ranges and for digital and analog signals.
Sniffing in Stavanger – Electrosmog Detector in the Rain!
Here’s a video of the Electrosmog Detector in action in the rain. Its much more noisy.
Sniffing in Stavanger – Electrosmog Detector
Here’s a video of the Electrosmog Detector in action during location scouting for the Electromagnetic Fountain in Stavanger.
Frequency range: 50 MHz to 3000 MHz
Conditions: very humid, sunny period between heavy rain.
Amplitude modulation explained
Here’s a tutorial from Radioteacher explaining Amplitude Modulation:
Sound analysis
I have been using Aleksander Refsum Jensenius’s max/msp sound analysis software to analyze digital and analogue signals that I have recorded with my detectors. When I see the sound rendered from different perspectives – loudness (spectral energy), brightness (spectral centroid), noisiness (spectral flatness), sonogram, pitch (estimated), onsets and as musical notation – in this way, I get to know more about the character of each of the various field recordings. The screenshot below is one moment of detecting the electromagnetic activity when I make a call on my mobile phone.
From this exercise I hope to glean some ideas about how to treat the data that will come in from the fountain’s detectors, and how this will control the various water valves of the fountain.
The digital signals are on-off and squirty – like premature ejaculations, while the anaolg signals are continuous and surgey and can be more kind of slowly orgasmic. What I am currently thinking of is passing each peak of the digital signals sequential to the small valves close to the circumference of the fountain bowl. As the peaks happen so fast, I figure that this is the best way of signal distribution – it allows for time for the mechanics of the each of the valves to respond before getting new input. Right now it seems like either the pitch or noisiness signal analysis methods would be the most useful way of controlling the valves. Pitch/peak opens a valve and sends a water jet into the air, the height controlled by its value, and then the valve closes fast to get a “drop”.
If you want to try this out, download the sound of my mobile (unedited from dv cassette/7.89mb) and then open/run it in Aleksander’s sound analysis patch. There’s a osx stand alone version, (1.6mb), so you don’t need to have max/msp installed on your mac.
Sniffer Sounds
From 11-12 March I’ll be leading a workshop for young people at the Amandus Film Festival in Lillehammer, Norway. Small groups, equipped with detectors and mini-dv cam-corders will explore electromagnetic Lillehammer, recording the sound of the invisible city directly on to tape as an alternative “concrete” sound for film. We’ll then look at the various recordings, discuss them a bit, and pick out interesting parts of the recordings. These will be shown on the last evening, together with the results of Ivar Smedstad‘s video group and will be loaded up to the Sniffer Sounds blog.