Improved Earth Grounds, G1 minor storm, space weather in the Media
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 magnet
ometer) 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
(be sure to hit refresh to pick up our latest changes and entries)
Project Documentation, Links and References
Journal Notes:
Sunday, January 1, 2012
Tuesday, January 3, 2012
Wednesday, January 4, 2012
Overnight: PDF, TXT. With chilly temperatures (<10 F) our NMR Tau2 values, related to the decay of the precession or free induction decay (FID) signal, have fallen as low as 0.4 seconds. With summer outside temperatures, the Tau2 values for our NMR working fluid (125 mL (4 Oz) Prestone De-Icer Windshield wiper fluid) are typically over 1.5 seconds.
Sunday, January 8, 2012
Overnight: PDF, TXT. Instrument Health: Polarization chart PDF, FDM FOM chart PDF.
Tuesday, January 10, 2012
Wednesday, January 11, 2012
Friday, January 13, 2012
Saturday, January 14, 2012
Tuesday, January 17, 2012
Overnight: PDF, TXT. Instrument Health: Polarization chart PDF, FDM FOM chart PDF. The air temperature sensor is currently in a LM34 long cable circuit that clamps about 0 F, so two periods of below zero weather show as flat lines. (We are looking at a LM335 circuit that covers a range of about -40 F to +125 F). Note that the fluid temperature is calculated directly from the measured NMR tau 2 times each measurement cycle. Also, amplitude regulation (the PEV servo) was slightly worse during the cold periods. However, the figure of merit (FOM) curves look fine.
Wednesday, January 18, 2012
Overnight: PDF, TXT. Instrument Health: Polarization chart PDF, FDM FOM chart PDF. Ran overnight at a reduced polarization current of 1.2 A (normally 1.5 A). At cooler temperatures, the increased polarization time was still under 1.5 seconds. Next, I want to go back to the old hp 6237B power that we began with (voltage mode only, no auto-switchover to constant current operation) to confirm that the system runs okay in a simpler configuration.
Thursday, January 19, 2012
Friday, January 20, 2012
Saturday, January 21, 2012
Overnight: PDF, TXT. Both the US Space Weather Prediction Center and NRCan Space Weather Forecast (evening PDF ) are calling for a CME related (predicted glancing blow) minor geomagnetic storm tomorrow.
Sunday, January 22, 2012 - G1 Minor storm
Overnight: PDF, TXT. First geomagnetic activity in some months began with a very fast leading edge, but only modest amplitude (<15 nT) sudden magnetic impluse after 1:15 am here in upstate, NY. There was also a far slower negative slope event of about 20 nT just before 7 am local time. It will be interesting to see if that was the CME related event predicted earlier, or if there is more disturbed space weather to come today. Interesting Aurora forecast link: Aurora Forecast, Geophysical Institute, University of Alaska Fairbanks. Afternoon: The local field is active, however magnetic field excursions have generally remained under 40 nT PDF. USGS Space Weather Now has called a G1 minor geomagnetic storm PDF. So far, in our upstate, NY area (in the sub-auroral region), the event has been relatively minor, albeit with some very fast storm like edge transitions in the field.
Monday, January 23, 2012
Overnight: PDF, TXT. NOAA Space Weather Prediction Center, Top News of the Day is predicting a moderate G2 to strong G3 magnetic storm, with a "Coronal Mass Ejection is expected to arrive about 1400 UT (9am EST) Jan 24" PDF.
Tuesday, January 24, 2012 - G1
Overnight: PDF, TXT. The first Geomagnetic Sudden Impulse was observed just after 10 am local time (1500 or -5 UTC). The impulse had a very fast leading edge with about a 25 nT excursion amplitude PDF. While the slope was noteably fast (25 nT / 4 minutes), so far the event has been relatively modest (K4, sub-storm), as magnetic storms go. The event commenced during our normal diurnal down-turn in our local total field. The gentle down-turn in the morning which precedes and follows the 1500 UTC sudden magnetic impulse was attributed to the normal diurnal cycle. The Canadian geomagnetic organization of Natural Resources Canada (NRCan) Tabular Forecast is predicting a more significant impact in the auroral zones (north of our observatory, which falls in the "sub-auroral" zone) PDF. NOAA Space Weather noted early observation of the magnetic impulse (half an hour before the event) by the ACE satellite PDF. 2:30 pm, now G1 PDF, we have storm like patterns, however amplitude swings have still been modest in the total field here in upstate, NY. Evening PDF, So far (our understanding is that watches are warnings are still active, stay tuned), at least as to total field (the "F scalar"), this event has been very minor in upstate, NY. The leading edge of the first impulse had a very high dB/dt, otherwise maximum amplitude fluxuations have been below 40 nT. 7:03 pm local (0003 UTC) PDF.
While we will continue to log daily journal entries as PDFs to have them in our journal records, real-time viewers can review the "live view" magnetogram at the top of the page.
Wednesday, January 25, 2012
Overview of the minor 1/24 - 1/25 magnetic storm PDF. Mark Haun's observations with his FDM PPM in the Seattle, WA area PDF. Since the FDM PPM also writes data to a text file, data can be plotted in any number of styles and programs in post-processing. Here, Mark plotted his data against data from NRCan Victoria. At a one minute sample rate, Mark's observatory did properly record the initial very fast positive going spike.
Afternote: On review of the NRCan OTT record PDF, it appears that we missed the very fast initial positive going spike. This is believed not to be an instrument failure, but rather our failure to go to a more suitable higher sampling rate. Unfortunately, we were still sampling at two minute intervals. The FDM PPM can sample as fast as about once per 10 to 15 seconds, however, we normally sample at 2 minute intervals since it gives a more legible display. We did a similar comparison to NRCan OTT. In the following graph, 1400 UTC to 2400 UTC, we had only 291 data points compared with NRCan's 600 data points. Also, our field was artificially offset to graph on the same scale (I guess we could do dual Y axis in the future). The "roughness" of our data plot shows the need for higher sample rates during fast moving events. However, some small differences may also be attributed to the 200 miles distance between our stations (NRCan OTT is about 200 miles north of our location) PDF.
The overall event, at our location, was very minor (from a geomagnetic total field point of view, here in upstate, NY). However, we did move from 100 nT full scale (vertical scale) to 200 nT for an ~80 nT slow field swing overnight. Perhaps it was more significant as a solar radiation (charged particles) and/or as a radio event. This CNN report "strongest since January 2003" suggests so, anyway. From a total field view, it was less significant locally than the October, 2011 event and several others listed in our past journal entries. Evening: shutting down for a Windows update, here is the recent data PDF, TXT.
There was certainly ample warning from the NOAA SPWC, starting 24 hours before the event. Interested people and organizations should sign up for NOAA space weather alerts at the NOAA SWPC Product Subscription Service. After you sign up for the email notifications (bottom of the SWN page) be sure to go to the "subscription" page to check off which categories of the many types of notifications that are available that you want to receive (or, you get nothing). The number of emails increased significantly nearing and during the event, however it is good to see there will likely be good warning and near real-time updates when a more significant event occurs someday.
Thursday, January 26, 2012
Friday, January 27, 2012
Overnight: PDF, TXT. Since missing some fine details in the recent minor storm, we have shifted our "normal" measurement rate to once per minute from once per two minutes. The display is less visually pleasing on our standard 12 hour graph, we need to look at LabView graphics options to see if we can improve the "readability" for the new faster rate. A FDM PPM can run as fast as ~5 to 10 seconds depending on the polarization time in use and the computer execution speed of the FDM frequency estimator. At a two minute measurement cycle, we were predicting 1,000 to 3,000 hours relay life. Faster measurement times might mean several relay change outs per year (to be determined). With just under 10,000 relays in stock, this is not anticipated to be a problem! (FDM PPM kits come with five relays). We had some FET failures with the original IRFIZ24N due to suspected reverse avalanche failure. So far, no failures with the more robust IRFI1310N (single pulse avalanche energy (EAS ) 420 mJ!).
Carl Olsen reported that he solved a noise problem by sinking a ground rod to provide a dedicated earth ground for his indoor instrumentation (power supply, USB 6008, and computer). Long term readers will recall that I have been noting odd disturbances in our measured NMR tau 2 data that seem to show up on some regular basis. Recently, we went back to a very simple triple output power supply, the hp 6237B for all three supplies (plus/minus negative rails and the polarization supply). At 1.2 A for polarization, it might be marginal with longer NMR tau 1 times in summer temperatures, however it is more than adaquate now. With our simpler setup, I connected the hp 6237B chassis ground connector to a #12 ground wire to our cold water supply entrance point and cast off the house power ground by using a "cheater" three prong to two prong adapter. It is too soon to say anything difinitive, however our % success rate for a fom of 2e-6, has jumped to 89% (similar to Carl's report) and, at least for the recent 12 hours or so, there have been no tau 2 disturbances. This recent polarization time controller chart is among the best we have ever seen! PDF. Caution to US experimenters, there are possible issues with the National Electric Code (NEC) using a dedicated earth ground for your FDM PPM. Perhaps there is an exception for scientific instrumentation, we need to look into this further. On the other hand, it is probably a non-issue for small setups typically running on extension cord type outlet strips (as opposed to making permanent changes to building wiring). Running on a dedicated ground rod appears to remove noise coupling from typical building ground currents (which should be zero, however in the mV microVolt range, our concept of zero ground current is no doubt far below what the code would call "zero" ground current).
Interesting article, "A Perfect Storm of Planetary Proportions, How a solar superstorm could take down power grids everywhere" by John Kappenman in the February, 2012 IEEE Spectrum magazine. The article discusses predicted mass failure of our power grid in the event of a massive geomagnetic storm, similar to what others refer to as a high impact low frequency (HILF) event. Unfortunately, it appears similar to risks in our world ranging from tsunamis and earthquakes to meteor impacts, not a matter of whether it will happen, but when. Governments will need to assess the risk and allocate resources (e.g. for protection systems and spare major high voltage distribution transformers) as this risk fits into the grand collection of global risks. As we have mentioned before, if you hope to record a full HILF event with your FDM PPM kit, you should consider an uninterruptable power supply with one or more large batteries! Speaking of media, there is a segment, "How ‘Space Weather’ Affects Planes And Power Grids" on this afternoon's NPR Science Friday show.
Saturday, January 28, 2012
Instrument health: polarization controller chart PDF, FDM amplitude and FOM PDF. Performance continues to be exceptionally good since we moved over to a dedicated earth ground (our cold water entry to the building). It is still too early to say for sure, however since going back the dedicated ground, we still have not seen the disturbances in our NMR tau2 measurements that seemed to occur at least once a day. Builders should probably consider a dedicated cold water pipe or dedicated ground rod for best performance.
Sunday, January 29, 2012
Monday, January 30, 2012
Overnight: PDF, TXT . There was more discussion of space weather, including geomagnetic storms today on WBUR's morning radio show, "On Point" this morning, The Breathtaking Power And Beauty Of The Sun.
Want to build your own FDM Proton Precession Magnetometer?
Project Documentation, Links and References
QUESTIONS/COMMENTS/notice of typos, etc. send email to joegeller @ gellerlabs dot com
COPYRIGHT © 2009, 2010, 2011 JOSEPH M. GELLER, All rights reserved.