[TangerineSDR] Fwd: another 24hour RM3100 run and comparison with Fredericksburg
Julius Madey
hillfox at fairpoint.net
Tue Oct 13 20:39:48 EDT 2020
I think that would work. Have to finish some assembly here and then
come up with a schedule.
Jules
On 10/13/2020 5:13 PM, Dr. Nathaniel A. Frissell Ph.D. wrote:
>
> Hi Hyomin and Jules,
>
> If I’m available, I’d like to join you as well. I’d really enjoy
> getting to meet Jules in person.
>
> 73 de Nathaniel
>
> *From:* Kim, Hyomin <hmkim at njit.edu>
> *Sent:* Tuesday, October 13, 2020 5:02 PM
> *To:* Julius Madey <hillfox at fairpoint.net>
> *Cc:* TAPR TangerineSDR Modular Software Defined Radio
> <tangerinesdr at lists.tapr.org>; John Gibbons <jcg66 at case.edu>; David
> Witten <wittend at wwrinc.com>; Dr. Nathaniel A. Frissell Ph.D.
> <nathaniel.frissell at scranton.edu>
> *Subject:* Re: [TangerineSDR] Fwd: another 24hour RM3100 run and
> comparison with Fredericksburg
>
> Hi Jules - Thanks for your tip. Would you be willing to come down here
> to install it together? It would be fun!
>
> All - It appears that the magnetometer I have is behaving well.
> However, it would be better if I have about >2 sets so I can check
> whether all the sensors are consistently behaving (which is extremely
> important for such a largely spaced network configuration). Do we have
> a timeline for more testing sets? If not, I will visit Jenny Jump to
> install the sensor again with a better temperature management scheme
> as Jules suggested.
>
> Sorry for my slow response. I am quite swamped by my teaching workload
> this semester (somewhat unexpected...).
>
> Cheers,
>
> Hyomin
>
> NJIT logo <https://www.njit.edu/>
>
>
>
> *Hyomin Kim*
> Assistant Professor
> Physics
> Center for Solar-Terrestrial Research
> Institute for Space Weather Sciences
> hmkim at njit.edu <mailto:hmkim at njit.edu> • (973) 596-5704
> https://web.njit.edu/~hmkim/
> 104 Tiernan Hall, 161 Warren Street, Newark, NJ 07102
>
> On Mon, Oct 5, 2020 at 6:07 PM Julius Madey <hillfox at fairpoint.net
> <mailto:hillfox at fairpoint.net>> wrote:
>
> Hyomin,
> During your run, the temperature of the 3100 was probably
> reasonably constant so your result is consistent with basic 3100
> specs. Keeping the temperature constant over 24 hours should give
> you a close alignment with future JJ station measurements. Good news.
> I can house your rm3100 in the same way I did mine or, I think I
> have enough extra parts now from Dave to make one up and send it
> down .... possibly drive it down since you're about 150 road miles
> from here, which I can do in three hours.
> Jules
>
> On 10/5/2020 5:31 PM, Kim, Hyomin wrote:
>
> Hi Dave, Jules and Nathaniel,
>
> Sorry that it took me so long to work on the data that was
> retrieved from Jenny Jump. The two sensors (Bartington and our
> mag) were placed inside a solenoid which was then placed
> inside a mu-metal case. Long story short, there is NO reason
> to believe that our magnetometer behaves in a different way
> compared to the other. They trace the artificially generated
> fields well. The only thing that needs to be addressed later
> is that the given field was so big that the output signals
> were saturated - the fields inside the solenoids should have
> been decreased to avoid saturation. My oversight that I had to
> leave the site in a rush. However, both sensors traced the
> fields in the same way. I hope I will have more time to stay
> at Jenny Jump next time to monitor the signals more carefully
> as the NJIT system has now been fixed.
>
> Please share this during the Tangerine meeting tonight as I
> will not be able to attend it this time due to the conflict
> with my lecture which is expected to be longer than last week...
>
> Hyomin
>
>
> NJIT logo <https://www.njit.edu/>
>
>
>
> *Hyomin Kim*
> Assistant Professor
> Physics
> Center for Solar-Terrestrial Research
> Institute for Space Weather Sciences
> hmkim at njit.edu <mailto:hmkim at njit.edu> • (973) 596-5704
> https://web.njit.edu/~hmkim/
> 104 Tiernan Hall, 161 Warren Street, Newark, NJ 07102
>
> On Tue, Sep 22, 2020 at 9:45 PM Julius Madey via TangerineSDR
> <tangerinesdr at lists.tapr.org
> <mailto:tangerinesdr at lists.tapr.org>> wrote:
>
> Dear John,
> Yes, temperature information was posted a while back. PNI
> initially claimed that there was no temperature effect due
> to the essentially self compensating scheme used for field
> measurement. After I measured as much as a 7-10nT per
> degree C tempco in some controlled oven experiments and
> sharing that data with PNI, PNI eventually replied that
> engineering had measured a maximum of +/- 2nT per degree C
> for the inductors alone but had not characterized the
> complete sensor.
>
> The data I have taken so far is not complete but indicates
> that the tempco (1) may not be equal on all axes,
> including differences in sign and (2) may not be assumed
> to be equal for any two units and (3) may not be linear
> with temperature, making algorithmic correction of the
> recorded data difficult.
>
> Hence, my attempts to achieve temperature stabilization to
> better than 1 degree C over 24 hours for the recordings
> I've been doing (sensor in a housing that can be easily
> buried sub surface).
>
> Have also done some experiments with an insulated chamber
> containing a thermal mass, equivalent to a low pass
> filter, to achieve stabilization.
>
> Another approach is a temperature controlled oven set to a
> few degrees above expected maximum local ambient temp but
> that requires power, which complicates long cable runs.
>
> At just 19-20 inches below grade in my shaded woodlot, 24
> hour temperature stability has been within 0.7C. Another
> 12-16 inches for the next install should bring that to a
> diurnal variation of perhaps 0.1C in this location.
>
> Jules K2KGJ
>
>
> On 9/22/2020 7:52 PM, John Gibbons wrote:
>
> All,
>
> I have not kept up on this thread due to other
> commitments, but I don't see any mention of the
> temperature data and plotting correlated to the data
> acquisition of the 3 axis magnetometer (or more likely
> I missed it).
>
> I believe that the RM3100 uses ferrite core inductors
> for the 3 axis magnetic pickups and ferrites
> definitely have a tempco (voice of experience...).
> Even a 1 Deg C may have an impact on the mu of the
> ferrite at the 1nT measurement levels.
>
> You've probably already done this (if so please point
> me to it) but has this been looked at / tested for /
> quantified?
>
> John N8OBJ
>
> John C. Gibbons
>
> Director - Sears Undergraduate Design Laboratory
>
> Dept. of Electrical Engineering and Computer Science
>
> Case Western Reserve University
>
> 10900 Euclid Ave, Glennan 314
>
> Cleveland, Ohio 44106-7071
> Phone (216) 368-2816 <tel:216-368-2816> FAX (216)
> 368-6888 <tel:216-368-6888>
> E-mail: jcg66 at case.edu <mailto:jcg66 at case.edu>
>
> On Mon, Sep 21, 2020 at 4:18 PM Julius Madey via
> TangerineSDR <tangerinesdr at lists.tapr.org
> <mailto:tangerinesdr at lists.tapr.org>> wrote:
>
> Forgot to mention that one thing to keep in mind
> is the difference in raw data processing between
> the absolute value sliding 1minute average plots I
> do with a spreadsheet with the more complex
> algorithm delta B plots from Intermagnet. I'm not
> sure how the 10nT anomaly would appear if the same
> Intermagnet processing algorithm was used.
> Hyomin ?????
>
> On 9/15/2020 10:38 AM, Phil Erickson wrote:
>
> Hi Dave,
>
> The X and Y traces return after 24 hours to
> nearly the same relative value in both the
> reference and RM3100 traces. The Z trace does
> not. Ionospheric currents flowing in the E
> region should not affect Z exclusive of X and
> Y under most any geometry I can think of, so I
> wondered whether the uncalibrated RM3100 was
> likely causing this. (I have never
> professionally calibrated a magnetometer, so
> Hyomin might need to comment here.). In other
> words, I always assume there is some
> measurement systematic until it has been
> completely ruled out before assigning it to
> geophysical variation.
>
> 73
>
> Phil W1PJE
>
> On Tue, Sep 15, 2020 at 10:34 AM David Witten
> <wittend at wwrinc.com
> <mailto:wittend at wwrinc.com>> wrote:
>
> @Phil,
>
> Correlation is great, and surely some
> further calibration issues may remain.
> But these sensors are NOT colocated -
> (200-300+ mi apart?) . Wouldn't it be
> suspicious if they did correlate
> perfectly? If they did, shouldn't we ask
> if we do really need an extensive array of
> these sensors? Presumably there will
> always be some local variation at this
> scale? (don't know, just asking)
>
> Dave Witten, KD0EAG
>
> On Tue, Sep 15, 2020 at 7:21 AM Phil
> Erickson <phil.erickson at gmail.com
> <mailto:phil.erickson at gmail.com>> wrote:
>
> Hi all,
>
> There appears to be a 10 nT drift in
> the Z component for the RM3100 that is
> not in the Fredericksburg traces. Is
> that slow systematic bias expected?
> Maybe things are not calbrated over
> that time frame quite yet?
>
> 73
>
> Phil W1PJE
>
> On Mon, Sep 14, 2020 at 10:49 PM David
> Witten via TangerineSDR
> <tangerinesdr at lists.tapr.org
> <mailto:tangerinesdr at lists.tapr.org>>
> wrote:
>
> I don't believe that my previous
> post carried the file K2KGJ provided.
>
> ---------- Forwarded message ---------
> From: *Julius Madey*
> <hillfox at fairpoint.net
> <mailto:hillfox at fairpoint.net>>
> Date: Mon, Sep 14, 2020 at 4:26 PM
> Subject: another 24hour RM3100 run
> and comparison with Fredericksburg
> To: Kim, Hyomin <hmkim at njit.edu
> <mailto:hmkim at njit.edu>>, David
> Witten <wittend at wwrinc.com
> <mailto:wittend at wwrinc.com>>, Dr.
> Nathaniel A. Frissell Ph.D.
> <nathaniel.frissell at scranton.edu
> <mailto:nathaniel.frissell at scranton.edu>>,
> Dave Larsen <kv0s.dave at gmail.com
> <mailto:kv0s.dave at gmail.com>>
>
> All,
> I was hoping to record a
> relatively short term event but
> missed one about 10 days ago.
> However, there was a good run on
> the 12th with an ~30nT excursion
> on the Y axis lasting about an
> hour. In the attached pdf, the
> three axes of the RM3100 again
> track the Fredericksburg
> magnetometer station data quite
> closely. The RM3100 plotted data
> points are simple running 60second
> averages and not the more complex
> filtering algorithm used by
> Intermagnet stations for their 1
> minute data points.
>
> The vertical axes scales on all
> plots are as close as I could
> match them by eye in cutting and
> pasting.
>
> I believe the value to the right
> on the Intermagnet plot is the
> mean for the 24 hour period. I
> did not try to compute a 24 hour mean.
>
> One of the products for the future
> for general interest would be a
> running plot like those available
> on Intermagnet.org. I guess we can
> dream a bit.
>
> Jules - K2KGJ
>
> --
> TangerineSDR mailing list
> TangerineSDR at lists.tapr.org
> <mailto:TangerineSDR at lists.tapr.org>
> http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>
>
> --
>
> ----
> Phil Erickson
> phil.erickson at gmail.com
> <mailto:phil.erickson at gmail.com>
>
>
> --
>
> ----
> Phil Erickson
> phil.erickson at gmail.com
> <mailto:phil.erickson at gmail.com>
>
> --
> TangerineSDR mailing list
> TangerineSDR at lists.tapr.org
> <mailto:TangerineSDR at lists.tapr.org>
> http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>
> --
> TangerineSDR mailing list
> TangerineSDR at lists.tapr.org
> <mailto:TangerineSDR at lists.tapr.org>
> http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20201013/c38cd638/attachment-0001.html>
More information about the TangerineSDR
mailing list