VLF/ULF: A nice whistler again... | some vlfrx tools stuff

[DK7FC <selberdenken@posteo.de>]

This morning, while listening the E field from my tree i suddenly heared 
a nice strong whistler again.
I extracted the short section using
vtread -T2019-08-11_06:24,+62 /raw | vtcat -p | vtmix -c0,0,1 | vtfilter 
-a th=4 -h bp,f=2800,w=5000 | vtresample -r12000 -g100 >  
whistler11082019.vt
Since i have access to the database at DL0AO, i produced the same file 
there:
vtread -T2019-08-11_06:24,+62 /raw | vtcat -p | vtmix -c0,0,1 | vtfilter 
-a th=4 -h bp,f=2800,w=5000 | vtresample -r12000 -g100 >  
whistler11082019_0ao.vt
Using scp i transferred the two files over to my notebook. There i 
equalised the audio levels of both recordings using
vtfilter -g8  whistler11082019_0ao.vt > whistler11082019_0ao2.vt
Afterwards, the files were combined using
vtjoin whistler11082019.vt whistler11082019_0ao2.vt whistler11082019_FCAO.vt
and finally a MP3 file was generated using
vtcat -S56 whistler11082019_FCAO.vt | vtraw -ow | lame -b64 - - >  
whistler11082019_FCAO.mp3
Now one can listen to the whistler event (6 seconds, attached) using 
headphones, where the signal of DK7FC is on the left ear and the signal 
of DL0AO is on the right ear.
73, Stefan

whistler11082019_FCAO.mp3
Description: audio/mpeg