[TangerineSDR] Fwd: another 24hour RM3100 run and comparison with Fredericksburg

Tue Oct 13 23:33:34 EDT 2020

Sounds good. Looking forward to it!
We also have to coordinate with Gil or Chris (another NJIT engineer) who
will escort us there.

Hyomin

[image: 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 • (973) 596-5704
https://web.njit.edu/~hmkim/
104 Tiernan Hall, 161 Warren Street, Newark, NJ 07102

On Tue, Oct 13, 2020 at 8:40 PM Julius Madey <hillfox at fairpoint.net> wrote:

> 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> <hmkim at njit.edu>
> *Sent:* Tuesday, October 13, 2020 5:02 PM
> *To:* Julius Madey <hillfox at fairpoint.net> <hillfox at fairpoint.net>
> *Cc:* TAPR TangerineSDR Modular Software Defined Radio
> <tangerinesdr at lists.tapr.org> <tangerinesdr at lists.tapr.org>; John Gibbons
> <jcg66 at case.edu> <jcg66 at case.edu>; David Witten <wittend at wwrinc.com>
> <wittend at wwrinc.com>; Dr. Nathaniel A. Frissell Ph.D.
> <nathaniel.frissell at scranton.edu> <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
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> [image: 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 • (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> 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
>
>
>
>
>
>
> [image: 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 • (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> 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 <216-368-2816> FAX (216) 368-6888 <216-368-6888>
> E-mail: jcg66 at case.edu
>
>
>
>
>
> On Mon, Sep 21, 2020 at 4:18 PM Julius Madey via TangerineSDR <
> 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> 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>
> 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> wrote:
>
> I don't believe that my previous post carried the file K2KGJ provided.
>
> ---------- Forwarded message ---------
> From: *Julius Madey* <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>, David Witten <wittend at wwrinc.com>, Dr.
> Nathaniel A. Frissell Ph.D. <nathaniel.frissell at scranton.edu>, Dave
> Larsen <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
>
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>
>
>
> --
>
> ----
> Phil Erickson
> phil.erickson at gmail.com
>
>
>
>
> --
>
> ----
> Phil Erickson
> phil.erickson at gmail.com
>
>
>
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