VLF,
The mails are coming in quickly now.
Some background: Paul Nichsolson (well known at least from the last
years VLF tests) has probably the most sensitive RX antenna on VLF in
the UK. He works a lot with PC analysis of weak VLF signals. A few
weeks ago he informed me that there is a Mike Smith in USA who has an E
field receiver for VLF and set up Paul's software for analysis. They
are always recording the VLF data to a HDD to have the chance to
re-process it later and add some special filters and so on. Also they
distribute their data stream via the net and so Paul can analyse the
the signal from Mike at home in UK.
In this test they try to pick my signal out of the noise over a
transatlantic distance, with further statistic data (proofing that this
signal is not by accident (or guesswork ;-) ). It will neither be a
"message" nor a spectrogram but just a peak coming out of the noise on
EXACT the frequency (+- 1 uHz or so). Quite exciting what they seem to
work out right now. If this test will be successful and we will have
that peak, then we will have some further informations on how many dBs
are missed to transmit a short message, like "K" or so, which comes a
bit closer to the usual work done by hams ;-)
I will forward surther informations about Mikes locator and further
deteils of his RX system if i will get some...
Attached you'll find the latest mail and information status.
73, Stefan/DK7FC
-------- Original-Nachricht --------
Mike,
Attached spectrum for first 2 hours of Stefan's transmission.
8970 peak now at about 4 sigma.
That peak is not there before 17:00.
I am analysing the signal recorded from the coherent stream
vlf27f here via vtvorbis and vtwrite to my local disk.
Don't want to run this on your vlf01 host as it will hammer
the disk and risk upsetting vttime. We haven't tested that yet!
All the CPU fans on both my quad core machines are full on as
I work through the data...
There are at least 6 computers involved in this test, not
counting Stefan's SpecLab PC. Timestamped signal streams are
crossing back and forth all over the place... fingers crossed
it all holds up...
Have to check now to make sure your 8970 peak is not some
cross-talk between the two channels of the coherent pair vlf27f
...later a scan of your local raw timed data will eliminate that
possibility for sure. But for now I can check the relative
phase between the two channels, we should see variation...
--
Paul Nicholson
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