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

Tue Sep 15 11:51:19 EDT 2020

I am quite impressed by the overall performance neverthelss as it detected
most of the small-scale (intensity-wise) variations at a 5-10 nT level.

I'd be very excited if I could see the sensors distributed over a large
region to observe large-scale convections and magnetic perturbations at a
high-spatial resolution which has never been done at any level.

[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 15, 2020 at 11:45 AM Phil Erickson <phil.erickson at gmail.com>
wrote:

> If it is picking up a 10 nT level secular change, that is fabulous for a
> reasonable cost sensor!  Maybe Jules has a ground induced current nearby?
> Anyhow, temperature sensitivity at a more precise level is I'm sure all
> part of the calibration needs, so we'll find out later...
>
> Phil
>
> On Tue, Sep 15, 2020 at 11:40 AM Kim, Hyomin <hmkim at njit.edu> wrote:
>
>> Ah, yes I agree - the secular change seems to be a little off. I
>> paid more attention to the small scale variations which look to be
>> similar. This is a mystery to me. Maybe our sensor is not so precisely
>> calibrated, say, to ambient temperature or something? Or we found another
>> magnetic anomaly near where Jules lives!!
>>
>>
>> [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 15, 2020 at 11:34 AM Phil Erickson <phil.erickson at gmail.com>
>> wrote:
>>
>>> Hi Hyomin,
>>>
>>>  You have a more expert eye than I do, so I read your statements as
>>> "uncalibrated axes", which of course is entirely correct for this RM3100
>>> data.  I just don't know how to separate the geophysical (latitudinal
>>> difference) from the instrumental (positional axes are not exactly the
>>> same).  I was reacting mostly to the 24 hour secular change in each
>>> component.  Is it reasonable to assume that is much less sensitive for
>>> horizontal vs vertical components?
>>>
>>> 73
>>> Phil
>>>
>>> On Tue, Sep 15, 2020 at 11:27 AM Kim, Hyomin <hmkim at njit.edu> wrote:
>>>
>>>> Hi Phil,
>>>> At a first glance I thought the Z traces matched well as the relative
>>>> values appear to be similar in that axis. If I am not wrong, Bz is oriented
>>>> toward the center of the earth for the USGS mags. I believe the USGS mag is
>>>> quite precisely oriented whereas our mag is not. Thus any slight offset in
>>>> orientation can be seen noticeably as Bz has the biggest values? Also, the
>>>> latitudinal difference between his place and Fredericksburg could be
>>>> another factor?
>>>>
>>>> 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 15, 2020 at 10:39 AM Phil Erickson via TangerineSDR <
>>>> tangerinesdr at lists.tapr.org> 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
>>>>>>>> --
>>>>>>>> TangerineSDR mailing list
>>>>>>>> TangerineSDR at lists.tapr.org
>>>>>>>> http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> ----
>>>>>>> Phil Erickson
>>>>>>> phil.erickson at gmail.com
>>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> ----
>>>>> Phil Erickson
>>>>> phil.erickson at gmail.com
>>>>> --
>>>>> TangerineSDR mailing list
>>>>> TangerineSDR at lists.tapr.org
>>>>> http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>>>>>
>>>>
>>>
>>> --
>>> ----
>>> Phil Erickson
>>> phil.erickson at gmail.com
>>>
>>
>
> --
> ----
> Phil Erickson
> phil.erickson at gmail.com
>
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