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Build a Geomagnetic Observatory ! GELLER Labs "Backyard Science"
Thoughts on a proton precession magnetometer design - a Proton Magnetometer Project. Build an Earth's field magnetometer.
The FDM MAGNETOMETER1 project is a low cost high performance proton magnetometer (a digital magnetometer) kit under development for universities and amateur scientists to be able to accurately measure and monitor changes in the Earth's total magnetic F field and to observe geomagnetic storms. Magnetic storms can cause large excursions in the field and are of concern to interests ranging from electrical power grids, radio communications, and satellite operations, to aurora watchers and amateur radio operators.
1 Filter Diagonalization Method "FDM" (harmonic inversion), see Jan 21 and Jan 23 entries, based on: Vladimir A. Mandelshtam, Howard S. Taylor, Harmonic inversion of time signals and its applications, Journal of Chemical Physics (1997), Volume 107, Issue 17, 1997, Pages 6756-6769
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Project Documentation, Links and References
Journal Notes:
Monday, July 4, 2011 - Kp4 (a sub-storm level)
Overnight: PDF, TXT, the spikes are vehicle related (e.g., newspaper delivery, garbage trucks, etc. Polarization time controller chart PDF, FDM amplitude and figure of merit (FOM) PDF. The polarization time controller varies the polarization time to maintain a substantially constant precession signal amplitude with changes in ambient temperature. Evening, there was a sudden impulse just after 5 pm local (UTC -4) PDF. 11:53 pm PDF. Very active late evening, early morning PDF.
Tuesday, July 5, 2011 - G1 minor magnetic storm
Overnight: PDF, TXT, longer time frame view of the 7/4 to 7/5 minor geomagnetic storm PDF, Wing Kp PDF.
Wednesday, July 6, 2011 - Thunderstorm
Overnight: PDF, TXT, there were slow changes in an active geomagnetic field overnight.
We closely observed the system during a passing thunderstorm this afternoon. While some of the individual precession waveform envelopes looked pretty ragged from time to time from lightning related EMI/RFI, there was no indication of any storm induced error in the magnetic field data. There might have been a few more auto-retries during the worst of it, however not enough to change the current success rate of about 81%. July 6, 2011 thunderstorm data.
There was an interesting negative going step change in the total field this evening just after 8 pm local (UTC -4) PDF, also seen throughout North America USGS (see around 0000 UTC 7/7/10) PDF.
Thursday, July 7, 2011
Friday, July 8, 2011
Overnight: PDF, TXT Late evening, early morning, there is a geomagnetic event underway after about 11 pm local (0300 UTC) PDF.
Saturday, July 9, 2011
Overnight: PDF, TXT, the geomagnetic field was active until about 2 am (0600 UTC).
Pre-kitsales price: $249.95! (Includes only all parts for the two electronics modules and beta Win7 software, see the link and our articles and docs page for more details.) The FDM Proton Precession Magnetometer kit would make a great summer time project for an advanced hobbyist or amateur scientist or a science student with a mentor having some electronics construction experience. Those without suitable frequency measurement gear or low level AC voltage test equipment can send their assembled modules/boards back for testing and initial calibration for $25 plus shipping both ways (usually USPS Priority Mail). Minor repairs (parts installed in the wrong location, failed chip, etc.) included; major repairs can cost extra. Reasonable technical support by email and/or phone is included! (There are occasionally some days when I am not available.) It would be great to get a few more amateur geomagnetic observatories up and running. I reduced the pre-kit sales price to encourage some more experimenters to try out this interesting project. Want to build one, but something is holding you back? Please tell us your concerns joegeller -at- gellerlabs.com.
Sunday, July 10, 2011
Overnight: PDF, TXT, Our Magnetogram (Total field "F" scalar) 0000-1800 UTC PDF (local is UTC -4), NRCan Ottawa 0000-1800 PDF, USGS 7/9 1807 UTC to 7/10 UTC PDF.
Monday, July 11, 2011
Overnight: PDF, TXT, interesting fast impulse (~10 nT) just before 5 am local (0900 UTC) followed by a negative going triangular waveform (about 0915 UTC, negative peak (~30 nT) about 0957 UTC, ended about 1018 UTC), NRCan OTT PDF, USGS PDF, Wing Kp PDF. A more detailed view PDF (spikes after 7 am (1100 UTC) are vehicle related). Midday, there has been a very fast change in the field (albeit small <10 nT) which I would have otherwise attributed to a newly arrived and parked vehicle PDF, NRCan OTT PDF.
There was some odd EMI/RFI this evening PDF (see the two top plots, the precession waveform with apodization and the precession waveform filtered envelope), probably out of band since it didn't show in the narrow band FDM spectra PDF or log spectra plots PDF. The Polarization controller chart looks fine PDF as does the FDM FOM and amplitude plot PDF. It went away as fast as it was noticed PDF, very odd. There was no apparent affect on the quality of the magnetic measurments.
Tuesday, July 12, 2011
Wednesday, July 13, 2011
Thursday, July 14, 2011
Friday, July 15, 2011
Overnight: PDF, TXT, interesting triangular shaped waveform (just over 10 nT, here in upstate, NY, US) with a negative going rounded recovery, just before 0500 UTC, seen throughout North America, NRCan OTT PDF, USGS PDF.
Saturday, July 16, 2011
Project Documentation, Links and References
Want to build your own FDM Proton Precession Magnetometer?
QUESTIONS/COMMENTS/notice of typos, etc. send email to joegeller @ gellerlabs dot com
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