On 17 Sep 2014 23:38, "Peter Putnam" <n...@sbcglobal.net> wrote: > > Greetings, > > The link below describes a homemade GPS receiver. > > It is presented in a detailed and elegant manner that is certain to appeal to this reflector's subscribers. > > Peter > > > http://www.aholme.co.uk/GPS/Main.htm
I don't understand the units of signal strength "The L1 carrier is spread over a 2 MHz bandwidth and its strength at the Earth's surface is -130 dBm. Thermal noise power in the same bandwidth is -111 dBm" Then goes on to talk about the signal being 20 dB below the noise. Unless the -130 dBm is over the whole surface area of the earth, which I doubt, the units make no sense to me. The units of signal strength should be V/m, A/m or W/square metre. The noise power should be in Watts or dBm. So taking the difference (19 dB, which is approximately 20 dB) between these figures seems odd to me. Dave _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
