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seismometer_positioning_system [2016/02/18 18:04] zashi [Seismometer Positioning System] |
seismometer_positioning_system [2016/02/18 18:15] zashi [Seismometer Positioning System] |
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| Or maybe Seismic Local Positioning System? Or Seismic Triangulating Positioning System? | Or maybe Seismic Local Positioning System? Or Seismic Triangulating Positioning System? | ||
| - | Using a system of seismometers (or perhaps accelerometers pressed into service as seismometers) that are networked together, it should be possible, with accurate clocks, to analyze input over, say, a 1-second rolling time window for frequency and amplitude to determine the source (epicenter) of the vibration. The time-window and frequency matching helps ensure the observed vibrations are from the same source. | + | Using a system of seismometers (or perhaps accelerometers pressed into service as seismometers) that are networked together, it should be possible, with accurate clocks, to analyze input over, say, a 1-second rolling time window for frequency and amplitude to determine the source (epicenter) of the vibration. The time-window and frequency matching helps ensure the observed vibrations are from the same source. The venerable Fourier Transform will be used to determine frequencies and amplitudes. |
| Amplitude and timing are used to determine distance. Timing is the primary factor for determining distance--assume speed of sound traveling through soft wood (see table below). Amplitude can be used as a sanity check (e.g. the sensor with the greatest amplitude should be closest). | Amplitude and timing are used to determine distance. Timing is the primary factor for determining distance--assume speed of sound traveling through soft wood (see table below). Amplitude can be used as a sanity check (e.g. the sensor with the greatest amplitude should be closest). | ||
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| Thus, sub milisecond time resolution is required. The multiplicative inverse gives a rough idea of necessary sampling frequency (regards to Nyquist). 167hz. Given the ready availability of of 1000+ Mhz processors, capable of sampling at or around clock speed (E.G. a Raspberry Pi), fast enough sampling and processing to get satisfactory accuracy should not be a problem. | Thus, sub milisecond time resolution is required. The multiplicative inverse gives a rough idea of necessary sampling frequency (regards to Nyquist). 167hz. Given the ready availability of of 1000+ Mhz processors, capable of sampling at or around clock speed (E.G. a Raspberry Pi), fast enough sampling and processing to get satisfactory accuracy should not be a problem. | ||
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| + | ===== Desirable Output ===== | ||
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| + | Once calculations have been made, the data should be presented via some graphical interface (web based, or a TK canvas) that overlays the calculated vibration epicenters on a map of the house. | ||
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| + | The net effect should be a graphical, real-time or near-real-time tracking of foot steps. | ||
