Decrease data usage with Blue hardware
#14
The next firmware comes with a simple stream compression (lzfx). It can save about 10-20% data, measured with my station. The compression is done on the whole UDP packet, so it's an additional reducing of size independently from the other methods which affect single signals only. Other implementations mentioned by kevin should do the same. However, some of them need much more memory, like zlib, which needs more memory than the CPU actually has. Wink   

Additionally there's now an encoding of each signal which cuts out the noise by transmitting just the min/max amplitude and the length of the noise (3 bytes instead of 64 max.). Of course this is not lossless, we loose some information - but if guessed correctly, it's just noise. It can save up to 90% data but also nothing, if the signal is above the noise level. In thunderstorms there's often just a narrow peak in the middle with nothing than noise before and after. A lot of data would be saved here.

Another encoding which saves the differences of consecutive samples will be added later. It will even work in combination with the noise filter from above.

There are already filters integrated, like the spike filter, which doesn't send signals with just a spike mainly caused by on-board interferences from the digital part. Additionally, signals with too low amplitude won't be transmitted at all.

Of course a filter or an encoding based on deeper signal inspection or FFT would be great, this was the plan since we have System RED. But this needs really much time for testing and research. Additionally our CPU is not fast enough for checking all signals all the time, even with the integrated DSP which can speed up such calculations.


There will be a beta firmware for RED systems with the implementations above very soon.
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RE: Decrease data usage with Blue hardware - by Tobi - 2016-01-19, 21:20



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