Re: VLF: Tonite...

[Markus Vester <markusvester@aol.com>]

Good decode from March 7 / 8 here as well, using only 4.4 hours of data:

ebnaut-rx V0.5
input file 03080424.wav
sample rate 0.514405 per second
rx frequency 8270
file start time 2017-03-08 02:11:35.900
polynomial 16K21A
crc size 16
number of chars 8
block size 64
symbol period 30.000
number of symbols 1344
list length 200000
start offset -13888.000
freq offset 0.100000
cores 2
padded 13887.893 seconds at start
padded 10505.343 seconds at end
initial reference phase -55.5
---------------------------------------------
found xxxxxxxx
list rank 0
reference phase  180  180  180  180
carrier RMS 9.103e+003 noise RMS 8.388e+002
carrier S/N 20.71 dB in 24.8 uHz
carrier Es/N0 -10.57 dB
carrier Eb/N0 4.12 dB
info bit period 884.21 seconds
symbol error rate 896/1344 = 66.667 %
Es/N0 from symbol errors -20.0 dB
Eb/N0 from symbol errors -5.3 dB
Shannon capacity 14.5 bits/hour
Shannon efficiency 28.0 %
symbols file 03080424-symbols.csv
elapsed 16 seconds


And another transmission started today at 18 UT, apparently same format as before but a different message. This one was decoded already after 3.6 hours:

ebnaut-rx V0.5
input file 03091924.wav
sample rate 0.514405 per second
rx frequency 8270
file start time 2017-03-09 17:11:35.800
polynomial 16K21A
crc size 16
number of chars 8
block size 64
symbol period 30.000
number of symbols 1344
list length 200000
start offset 2912.000
freq offset 0.100000
cores 2
skipped 2912.102898 seconds to start
padded 27305.339 seconds at end
initial reference phase -31.9
---------------------------------------------
found xxxx xxx
list rank 0
reference phase  180  180  180  180
carrier RMS 1.182e+004 noise RMS 2.568e+003
carrier S/N 13.26 dB in 24.8 uHz
carrier Es/N0 -18.03 dB
carrier Eb/N0 -3.33 dB
info bit period 884.21 seconds
symbol error rate 1021/1344 = 75.967 %
Es/N0 from symbol errors -20.0 dB
Eb/N0 from symbol errors -5.3 dB
Shannon capacity 2.7 bits/hour
Shannon efficiency 150.4 %
symbols file 03091924-symbols.csv
elapsed 15 seconds
---------------------------------------------
found xxxx xxx
list rank 0
reference phase -150 -150 -150 -150
carrier RMS 1.182e+004 noise RMS 2.568e+003
carrier S/N 13.26 dB in 24.8 uHz
carrier Es/N0 -18.03 dB
carrier Eb/N0 -3.33 dB
info bit period 884.21 seconds
symbol error rate 1012/1344 = 75.298 %
Es/N0 from symbol errors -20.0 dB
Eb/N0 from symbol errors -5.3 dB
Shannon capacity 2.7 bits/hour
Shannon efficiency 150.4 %
symbols file 03091924-symbols.csv
elapsed 28 seconds

73, Markus (DF6NM) 



-----Ursprüngliche Mitteilung-----
Von: Paul Nicholson <vlf0403@abelian.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mi, 8. Mrz 2017 20:15
Betreff: Re: VLF: Tonite...

Stefan wrote:

> f = 8270.100000 Hz
> Start time: Tuesday 07.Mar.2017 22:20:00.3
> Symbol period: 30 s
> Characters: 8
> CRC bits: 16
> Coding 16K21A

A good signal here:

carrier Eb/N0: 11.9 dB
carrier S/N: 28.50 dB in 24.8 uHz

Signal peaks at time offset +0.12 seconds

--
Paul Nicholson
--

03080424_sym.png
Description: PNG image

03091924_sym.png
Description: PNG image