Date: Sun, 17 Mar 2013 21:59:50 +0100
From: Steinar Aanesland <saanes@broadpark.no>
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Subject: Re: LF: A CME hit this morning
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Hi Markus

Thanks for your very interesting comment as usual :)

LA5VNA Steinar
loc:JO59jq



Den 17.03.2013 17:40, skrev Markus Vester:
> Steinar,
>=20
> thanks for this info. I think the signal which was visible in Chris=
' and my =B5Hz grabbers around 12 UT was a qrss transmission from RN3=
AGC.
>=20
> According to my understanding, from the Doppler shift you could est=
imate the vertical velocity of the layer but not the height. At verti=
cal incidence, 0.1Hz / 138kHz  would correspond to 0.36e-6 c ~ 108 m/=
s. However the movement would have to be faster when the same shift w=
as observed with oblique incidence, so the interpretation depends on =
the distance between TX and RX.=20
>=20
> I don't think Doppler on a narrowband signal alone will let you der=
ive the altitude of the layer, although in general LF signals will no=
rmally not be able to penetrate much beyond 100 km above ground. In t=
he "SXV ripples" observations, there was an obvious frequency depende=
nce across the 100 Hz wide spectrum, which seemed to indicate an unus=
ually large delay of about 10 milliseconds. This is still a riddle as=
 it can't easily be explained by vertical multihop propagation. So I =
believe there must have been a horizontally displaced and moving scat=
tering center, perhaps reminiscent of an Aurora reflection. But of co=
urse this is just speculation.
>=20
> Best 73,
> Markus (DF6NM)
>=20
>=20
> From: Steinar Aanesland=20
> Sent: Sunday, March 17, 2013 5:07 PM
> To: rsgb_lf_group@blacksheep.org=20
> Subject: Re: LF: A CME hit this morning
>=20
>=20
> Hi Markus
>=20
> My IC-R75 (X-tal oven) is in REV CW mode and the pitch is 600Hz .
> My frequency scale is calibrated after the time station on 77.5KHz
> (599.90Hz in the waterfall).  LA4ANA's beacon is 7.6Hz over the pit=
ch
> freq in the waterfall. I hope I am not thinking 180 degrees wrong n=
ow,
> but this gives me 137787.6.
>=20
> Markus, is it possible to estimate the hight of reflection layer , =
when
> you know the frequency and the doppler shift ?
>=20
>=20
> LA5VNA Steinar
> loc:JO59jq
>=20
>=20
> Den 17.03.2013 11:15, skrev Markus Vester:
>> Steinar,
>>
>> thanks for reporting this! The 0.1 Hz Doppler shift is remarkable.=
 Is your frequency scale upright or inverted?
>>
>> On a several occasions a few years back, I observed still unexplai=
ned "ripples" on SXV 135.8 kHz, which seemed to indicate a delayed co=
mponent with a similar-sized Doppler shift:
>> http://df6nm.bplaced.net/LF/sxv_ripples/sxv_ripples.htm
>>
>> What is strange is that according your screenshot the shifted trac=
e appeared from 4:15 to 4:45 UT, whereas the Boulder magnetometer sho=
ws a magnetic disturbance starting not before at 6:00:=20
>> http://www.swpc.noaa.gov/rt_plots/bou_12h.html
>>
>> BTW I wonder if LA4ANA's beacon would be detectable on one of our =
137780 Hz microHz grabbers here. Do you know his exact frequency, and=
 whether the carrier is phase continuous?
>>
>> Best 73,
>> Markus
>>
>>
>> From: Steinar Aanesland=20
>> Sent: Sunday, March 17, 2013 10:40 AM
>> To: *rsgb_lf_group@blacksheep.org=20
>> Subject: LF: A CME hit this morning
>>
>>
>> I think I picked it up with my 137Khz grabber. I am monitoring Rob=
ert
>> LA4ANA on 137780. It is ground wave between us, but I think I can =
see an
>> sky wave refection also when the storm hit the earth. What do you =
think?
>>
>> https://dl.dropbox.com/u/16381257/qrss60_multipath.jpg
>>
>=20
>=20
>=20