Temporary VLF Grabber near Bielefeld at DL4YHF or DF0WD, loc JO42FD.
Only active during 'special events'. Refreshes every few minutes when active. Details below .
Current status: Unknown. Frequently modified for testing; 2011-02-06.
Time markers indicate the 'center' of each FFT (since
there may be exaggerated overlap).
For example, with 60 minutes FFT window duration, the topmost line of the spectrogram appears 'late' by at least 30 minutes.
The image may look blurred after the program was started due to zero-padded FFT input .
More info about this grabber on the DL4YHF website .
Other VLF grabbers :
9 kHz band by Paul Nicholson Pontese observatory