ENLARGE Choose Target Entropy (bits) 4 3 2 1.5 1 .75 .5 .25 |
Using a compression algorithm
written by Chris Brislawn of Los Alamos' CIC-3, I performed eight compression
experiments on each of the thirteen signals.
The spectrogram on the right has been compressed with a target entropy of 3 (measured in bits). You can explore what the other levels of compression have done to the spectrogram by choosing the appropriate target entropy to the left. The lightning signature clearly has not been affected. You can begin to see how the compression is "averaging" the time/frequency bins where background noise occurs. This time/frequency-localization becomes more evident with increasing compression levels. This characteristic of wavelet compression preserves the parameters
from each lightning signature (contrast, TEC, lag, etc.) which we would
like to archive.
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