AI4WV's blog

I was just wondering what has been done with the data that we've been collecting? I would be interested in seeing what has been learned. It would be interesting to see if the data could be used to model path loss between various parts of the world maybe tying that in with solar activity. I must admit that at the moment I don't know were to start trying to put that kind of a model together, but if anybody has come up with results like that, please share. Maybe people have and I just missed it.
Thanks,
Steve
AI4WV

I am fairly new to wspr, I have been running the software periodically for a couple of weeks, and have started pondering how to relate this information to "real world" scenarios. I have come across a figure of -10dB SNR as a minimum usable signal level to decode PSK31 transmissions. If I look at most the spots where I have been received, I am usually well into the "minus teens or twenties". Has anybody looked at whether there is a predictable correlation between changes in transmit power and changes in received SNR? I transmit at 37dBM (5W). If I were to double my transmit power (3dB increase), would there be a predictable amount of change in SNR at the stations that receive me, or are there too many factors that affect my receive strength at any given station. Ultimately, I would like to see if we could use this wspr data to predict, for example, how much power should I expect to need to use to get a reliable PSK31 signal into Germany, from North Carolina, on 40m with enough strength to be received.