Kp 5, July operation, FDM Proton Precession Magnetometer Instrument Health
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:
Sunday, July 17, 2011
Overnight: PDF, TXT, NRCan OTT PDF. View of the diurnal cycle yesterday and this morning PDF. Compare to a similar view from last year (July 22, 2010) PDF. Notice how our nominal field has dropped over 100 nT in just one year.
FDM PPM magnetometer performance (instrument health). The performance graphs were plotted directly from the .txt file. Polarization Controller Chart PDF, air temperature at the sensor stand (orange curve) is affected by varying degrees of direct sun and full shade by trees during the day, FDM FOM (figure of merit) and amplitude PDF; sample measurement (from a dedicated version of FDM in post processing) FDM narrow band Log Spectra PDF, narrow band Spectra PDF.
Monday, July 18, 2011
Tuesday, July 19, 2011 - Kp5
Overnight: PDF, TXT. Afternoon: ~2 pm (1800 UTC) There appears to be some significant geomagnetic activity beginning, beyond the end of the normal diurnal cycle PDF, warning for K5 now at NOAA Space Weather Now PDF. 1830 UTC Nothing too dramatic so far, a relatively fast positive going change of ~25 nT PDF. Planatary Kp5 (a minor event) (some of the small step changes are vehicle related) PDF. 2109 UTC PDF. 2335 UTC two day view PDF. 0232 UTC Wing Kp is predicting more significant geomagnetic activity PDF, there was small, but relatively fast negative excursion of the total field PDF.
Wednesday, July 20, 2011
Overnight: PDF, TXT, Wing Kp index PDF, the geomagnetic field was unsettled to active overnight. 2234 UTC-The geomagnetic field remained unsettled to active most of the day PDF.
We ordered more NBLNA and SWCTRL PCBs to support FDM magnetometer kit sales today. Although these are "final" quality and style boards, we are still printing prototype quantities at $33 each, so each pre-sales kit begins with $66 in parts cost for just the PCBs! Kits include only all parts to build the NBLNA and SWCTRL modules and software. By the USB 6008 digitizer directly from National Instruments, or on eBay. Supply power supplies (homebrew or eBay surplus) and the other parts as per the articles and docs pages.
Thursday, July 21, 2011
Overnight: PDF, TXT. Afternoon: Interesting unsettled period PDF.
FDM PPM magnetometer performance (instrument health). The performance graphs were plotted directly from the .txt file. Polarization Controller Chart PDF, air temperature at the sensor stand (orange curve) is affected by varying degrees of direct sun and full shade by trees during the day, fluid temperature is computed from the measured fluid NMR tau 2. Note the lag of fluid temperature over air temperature (the working NMR fluid, Prestone De-Icer, is in a 125 mL Nalgene bottle in the powered coil PVC form). FDM FOM (figure of merit) and amplitude PDF.
Friday, July 22, 2011
Saturday, July 23, 2011
Sunday, July 24, 2011
Overnight: PDF, TXT, 2 day view PDF, very quiet overnight, overnight magnetogram shows the beginning of diurnal cycle. The field was lower overnight by about 2.5 to 3 nT from a vehicle parked at ~80 feet (~25 meters) from the sensor coil stand. Here, the field corrected to our normal value on vehicle departure (~1310 UTC) expanded scale PDF, PDF, NRCan Ottawa 1300 to 1320 UTC shows the regional trend in the same time frame (although we generally track the OTT magnetogram, comparison at the 1 nT level is more tenuous since we are 200 miles south of OTT) PDF.
Instrument health: We are presently operating in a servo mode where the polarization time is automatically changed to give a desired precession waveform peak envelope voltage, presently 0.85 V pk. Here is a graph of polarization times used plotted versus the measured NMR Tau 2 for some recent data (about 1600 points at 2 minutes per point) PDF. The scatter of longer Tau 2 values to the upper right is believed to be related to EMI/RFI interference of the precession waveform which causes an error in the Tau 2 decay measurement. Since the measured Tau 2 values are not used in the PEV servo mode, there is no error in the calculated polarization time set. More importantly, there is no evidence of degradation of the F Scalar value during such periods of disturbed Tau 2 calculations.
Monday, July 25, 2011
Tuesday, July 26, 2011
Overnight: PDF.
Wednesday, July 27, 2011
Overnight: PDF, TXT, the geomagnetic field (total field "F" scalar) was very quiet overnight followed by a picture perfect diurnal cycle today PDF.
Thursday, July 28, 2011
Overnight: PDF, TXT. Another very quiet magnetic diurnal cycle through the midday today PDF.
Friday, July 29, 2011
Overnight: PDF, TXT. The week in review, a 7 day magnetogram showing our local diurnal cycle in the total field (the "F" scalar) PDF (spikes and a large positive offset were due to vehicles).
Saturday, July 30, 2011 - K4, Kp5
Overnight: PDF, TXT. Some interesting geomagnetic activity this afternoon after several days of quiet PDF. 5:27 pm (2127 UTC) PDF, 2358 UTC PDF, 0139 UTC PDF today's event might be winding now. NOAA K PDF, Wing Kp PDF.
Sunday, July 31, 2011
Monday, August 1, 2011
Wednesday, August 3, 2011
Thursday, August 4, 2011
Overnight: PDF, TXT, the geomagnetic field was quiet overnight. There was an interesting very fast pulse edge just before 6 pm (2200 UTC) PDF seen throughout North America USGS PDF, NRCan Ottawa 2359 UTC PDF, 9:37 pm local PDF.
All parts are now in stock for a small number of FDM Magnetometer kit sales.
Project Documentation, Links and References
Want to build your own FDM Proton Precession Magnetometer? All parts are in stock now for a small number of "pre-kit" sales.
QUESTIONS/COMMENTS/notice of typos, etc. send email to joegeller @ gellerlabs dot com
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