[time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

[Mark Sims]

I am adding Truetime XL and XLi support to Lady Heather.   

Pretty much all GPS receivers report sig levels in dBc or SNR type values in the range of around 20 .. 50.   The Truetime XLi reports them in dBW with a range of around -196 to -145 dBW).   Does anybody know how to convert the dBW values into something more in line with standard dBc or SNR values?  The conversion does not need to be exact, it just needs to be reasonable looking...