<div dir="ltr">Hi Jules - Thanks for your tip. Would you be willing to come down here to install it together? It would be fun!<div><br></div><div>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. </div><div><br></div><div>Sorry for my slow response. I am quite swamped by my teaching workload this semester (somewhat unexpected...). </div><div><br></div><div>Cheers,</div><div>Hyomin</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><table style="border-collapse:collapse;width:525px;border-spacing:0px;background-color:transparent;color:rgb(35,38,54);font-family:Poppins,sans-serif;font-size:16px"><tbody style="border:0px;padding:0px;font-size:0.9em"><tr><td style="padding:5px;font-size:0.9em;font-stretch:normal;line-height:1.5;color:rgb(255,0,0);border-width:0px 3px 0px 0px;border-bottom-style:initial;border-bottom-color:initial;border-top-style:initial;border-right-style:solid;border-left-style:initial;border-top-color:initial;border-right-color:rgb(204,0,0);border-left-color:initial;width:180px;vertical-align:middle"><a href="https://www.njit.edu/" style="background-color:transparent;color:rgb(51,122,183)" target="_blank"><img src="https://assets.njit.edu/uicomponents/NJIT-email-logo.png" alt="NJIT logo" style="border:0px;display:block;vertical-align:middle;width:150px;height:auto;max-width:150px"></a></td><td style="padding:5px 5px 5px 10px;font-size:12px;font-stretch:normal;line-height:16px;border:0px;font-family:Arial,Helvetica,sans-serif"><strong style="color:rgb(111,111,111);font-size:13px">Hyomin Kim</strong><br><font color="#6f6f6f">Assistant Professor</font><br><font color="#6f6f6f">Physics<br></font><font color="#666666">Center for Solar-Terrestrial Research<br>Institute for Space Weather Sciences</font><br><font color="#666666"><a href="mailto:hmkim@njit.edu" target="_blank">hmkim@njit.edu</a> • <span style="white-space:nowrap">(973) 596-5704</span><br><a href="https://web.njit.edu/~hmkim/" target="_blank">https://web.njit.edu/~hmkim/</a><br>104 Tiernan Hall, 161 Warren Street, Newark, NJ 07102<br></font></td></tr></tbody></table></div></div></div></div></div></div></div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Oct 5, 2020 at 6:07 PM Julius Madey <<a href="mailto:hillfox@fairpoint.net">hillfox@fairpoint.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<font face="Arial">Hyomin,<br>
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. <br>
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.<br>
Jules<br>
<br>
</font><br>
<div>On 10/5/2020 5:31 PM, Kim, Hyomin
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Hi Dave, Jules and Nathaniel,</div>
<div>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. </div>
<div><br>
</div>
<div>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...</div>
<div><br>
</div>
<div>Hyomin</div>
<div><br>
</div>
<div><br>
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<td style="padding:5px;font-size:0.9em;font-stretch:normal;line-height:1.5;color:rgb(255,0,0);border-width:0px 3px 0px 0px;border-bottom-style:initial;border-bottom-color:initial;border-top-style:initial;border-right-style:solid;border-left-style:initial;border-top-color:initial;border-right-color:rgb(204,0,0);border-left-color:initial;width:180px;vertical-align:middle"><a href="https://www.njit.edu/" style="background-color:transparent;color:rgb(51,122,183)" target="_blank"><img src="https://assets.njit.edu/uicomponents/NJIT-email-logo.png" alt="NJIT logo" style="border: 0px; display: block; vertical-align: middle; width: 150px; height: auto; max-width: 150px;"></a></td>
<td style="padding:5px 5px 5px 10px;font-size:12px;font-stretch:normal;line-height:16px;border:0px;font-family:Arial,Helvetica,sans-serif"><strong style="color:rgb(111,111,111);font-size:13px">Hyomin Kim</strong><br>
<font color="#6f6f6f">Assistant
Professor</font><br>
<font color="#6f6f6f">Physics<br>
</font><font color="#666666">Center
for Solar-Terrestrial Research<br>
Institute for Space Weather Sciences</font><br>
<font color="#666666"><a href="mailto:hmkim@njit.edu" target="_blank">hmkim@njit.edu</a> • <span style="white-space:nowrap">(973) 596-5704</span><br>
<a href="https://web.njit.edu/~hmkim/" target="_blank">https://web.njit.edu/~hmkim/</a><br>
104 Tiernan Hall, 161 Warren Street,
Newark, NJ 07102<br>
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<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Tue, Sep 22, 2020 at 9:45
PM Julius Madey via TangerineSDR <<a href="mailto:tangerinesdr@lists.tapr.org" target="_blank">tangerinesdr@lists.tapr.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div> <font face="Arial">Dear John,<br>
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.<br>
<br>
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.<br>
<br>
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).<br>
<br>
Have also done some experiments with an insulated chamber
containing a thermal mass, equivalent to a low pass
filter, to achieve stabilization. <br>
<br>
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.<br>
<br>
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.<br>
<br>
Jules K2KGJ<br>
<br>
<br>
</font><br>
<div>On 9/22/2020 7:52 PM, John Gibbons wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)">All,</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)">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).</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)">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.</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)">You've
probably already done this (if so please point me to
it) but has this been looked at / tested for /
quantified?</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><br>
</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)">John
N8OBJ</div>
<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><br>
</div>
<div>
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<div>
<div>
<div>John C.
Gibbons<br>
</div>
Director -
Sears
Undergraduate
Design
Laboratory<br>
</div>
Dept. of
Electrical
Engineering
and Computer
Science</div>
</div>
Case Western
Reserve
University <br>
</div>
<div>10900
Euclid Ave, <span style="font-size:12.8px">Glennan 314</span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px"><br>
</span></div>
</div>
<div><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px">Cleveland,
Ohio
44106-7071</span><br style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px">
<span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px">Phone </span><a href="tel:216-368-2816" value="+12163684572" style="color:rgb(17,85,204);font-family:Helvetica;font-size:12.8px" target="_blank">(216) 368-2816</a><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px"> FAX </span><a href="tel:216-368-6888" value="+12163686888" style="color:rgb(17,85,204);font-family:Helvetica;font-size:12.8px" target="_blank">(216) 368-6888</a><br style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px">
<span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px">E-mail:
</span><a href="mailto:jcg66@case.edu" style="color:rgb(17,85,204);font-family:Helvetica;font-size:12.8px" target="_blank">jcg66@case.edu</a><br style="color:rgb(0,0,0);font-family:Helvetica;font-size:12.8px">
<br>
</div>
</div>
</div>
</div>
</div>
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</div>
</div>
</div>
</div>
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</div>
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<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Mon, Sep 21, 2020
at 4:18 PM Julius Madey via TangerineSDR <<a href="mailto:tangerinesdr@lists.tapr.org" target="_blank">tangerinesdr@lists.tapr.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div> <font face="Arial">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.<br>
Hyomin ?????<br>
</font><br>
<div>On 9/15/2020 10:38 AM, Phil Erickson wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Hi Dave,
<div><br>
</div>
<div> 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.</div>
<div><br>
</div>
<div>73<br>
</div>
<div>Phil W1PJE</div>
<div><br>
</div>
<div><br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Tue, Sep
15, 2020 at 10:34 AM David Witten <<a href="mailto:wittend@wwrinc.com" target="_blank">wittend@wwrinc.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">@Phil,
<div><br>
</div>
<div>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)<br>
</div>
<div><br>
</div>
<div>Dave Witten, KD0EAG</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Tue,
Sep 15, 2020 at 7:21 AM Phil Erickson <<a href="mailto:phil.erickson@gmail.com" target="_blank">phil.erickson@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">Hi all,<br>
<div><br>
</div>
<div> 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?</div>
<div><br>
</div>
<div>73</div>
<div>Phil W1PJE</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On
Mon, Sep 14, 2020 at 10:49 PM David
Witten via TangerineSDR <<a href="mailto:tangerinesdr@lists.tapr.org" target="_blank">tangerinesdr@lists.tapr.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">I don't believe that my
previous post carried the file K2KGJ
provided.<br>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">----------
Forwarded message ---------<br>
From: <strong class="gmail_sendername" dir="auto">Julius Madey</strong>
<span dir="auto"><<a href="mailto:hillfox@fairpoint.net" target="_blank">hillfox@fairpoint.net</a>></span><br>
Date: Mon, Sep 14, 2020 at 4:26
PM<br>
Subject: another 24hour RM3100
run and comparison with
Fredericksburg<br>
To: Kim, Hyomin <<a href="mailto:hmkim@njit.edu" target="_blank">hmkim@njit.edu</a>>,
David Witten <<a href="mailto:wittend@wwrinc.com" target="_blank">wittend@wwrinc.com</a>>,
Dr. Nathaniel A. Frissell Ph.D.
<<a href="mailto:nathaniel.frissell@scranton.edu" target="_blank">nathaniel.frissell@scranton.edu</a>>,
Dave Larsen <<a href="mailto:kv0s.dave@gmail.com" target="_blank">kv0s.dave@gmail.com</a>><br>
</div>
<br>
<br>
<div> <font face="Arial">All, <br>
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. <br>
<br>
The vertical axes scales on
all plots are as close as I
could match them by eye in
cutting and pasting.<br>
<br>
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.<br>
<br>
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. <br>
<br>
Jules - K2KGJ<br>
</font> </div>
</div>
</div>
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</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr">----<br>
Phil Erickson<br>
<a href="mailto:phil.erickson@gmail.com" target="_blank">phil.erickson@gmail.com</a><br>
</div>
</blockquote>
</div>
</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr">----<br>
Phil Erickson<br>
<a href="mailto:phil.erickson@gmail.com" target="_blank">phil.erickson@gmail.com</a><br>
</div>
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