[linux-dvb] How do I turn the signal/noise, siganl strength into meaningful values?

[Barry Scott]

Using the FE_READ_SIGNAL_STRENGTH, FE_READ_SNR and FE_READ_BER
I get numbers but need to understand how to turn them into useful to 
humans values.

I'm using AverMedia 771 DVB-T card and Pinnacle PCTV-SAT on 2.6.11 for FC3.

First observation is that FE_READ_SIGNAL_STRENGTH values seen to be 
smaller for larger signals.
Second observation use that FE_READ_SNR always duplicates bits 0-7 in 
8-15, why?

What are the units what is the scale?

Barry