Excellent diagnostic method and implementation.
Thanks also for applying the method to the ULF experiments, and to 3kHz
propagation in general. I don’t remember seeing a measurement of the type that
you have made, near the rather unique region of ~ 2.5 kHz to 4 kHz and at these
distances in which modal and polarization effects can be substantial. Very
Even the fact that the method is apparently robust at 3kHz to the path
disturbance caused by the aggregate lightning; and to the anisotropy of the
lightning is interesting and valuable. The accuracy of commercial lightning
geolocation for example couldn’t be extrapolated directly to a prediction of
robustness of your method to the path disturbance caused by aggregate
lightning; and to anisotropy of the lightning even with 172 sferics. Thank you
for a collection of valuable observations and findings
From: [email protected]
[mailto:[email protected]] On Behalf Of Paul Nicholson
Sent: Saturday, January 28, 2017 9:21 AM
To: [email protected]
Subject: Re: ULF: EbNaut over 3 wavelengths on ULF
On the 26th there was stormy weather all day near Marseille, not exactly
Heidelberg but it's a start. It's in the right quadrant but longer distance.
(It made me think of Garlaban and I ended up reading La lettre de Lili des
Bellons à Marcel Pagnol - moving and beautiful.)
I used vttoga to collect timings of all the sferics received at Todmorden,
Bielefeld and Cumiana during 10:00 to 14:00. Then I used vtspot to determine
which sferics originated in the region
of Marseille. This produced a list of 172 sferics to analyse.
I inspected each one using vtplot and discarded the scruffy ones, keeping the
vtcmp -m pd360 then compared the phase angles from the three rx channels during
I concluded that the relative phase of the channels was just as expected for
this quadrant at 3kHz. That means the propagation cannot be doing anything too
surprising with the polarisation at this frequency.