Reading a Seismogram
I have a seismograph of my own construction connected to computer
I get neat recordings but I want to read car and truck patterns.
How can I quantify my readings to "prove " a reading is a car?
You have a hypothesis -- "a seismograph will respond differently
to a car than it will to a truck." Now you need to perform experiments
to determine the validity of your hypothesis. Take data while observing
whether you are detecting a car or a truck. Compare the results and
see if there are any obvious differences -- e.g., different amplitudes,
noise levels, frequencies, etc. You may want to try doing a Fourier
transform of your data to see if certain frequencies are characteristic
of one type of vehicle or the other.
To do this job thoroughly you will want to take account of things like
vehicle speed and road surface.
Once you have done these experiments you may be able to refine your
hypothesis to be something like -- "trucks (18 wheelers) have an
enhanced signal at XXX hertz in the seismograph signal, relative to
cars." Then you can perform more experiments to verify this and even
quantify it -- for example you may find that cars have a signal intensity
less than YYY at XXX Hertz while trucks have a signal intensity of ZZZ
at the same frequency.
There is a lot of work involved but building the seismograph must have
taken a lot of work too! Your problem is very interesting and I would be
interested in hearing how it turns out. Keep us informed!
gregory r bradburn
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Update: June 2012