On Mon, Nov 15, 2010 at 6:20 PM, Drax Felton <[email protected]> wrote:
> How? I'd think the Doppler shift of a moving earth under the ionosphere > lag > or the gasses themselves would cause fractional Hz error alone. > > Or some other phenomena I'm like-wise ignorant of. > You are absolutely correct. I normally see ionospheric variations on the order of +/- 200mHz. I saw frequency variations of 800mHz for W8KSE on 80m. Even so, I was within 28mHz of the actual frequency after my data processing. The art to the FMT is looking at the frequency plot and then trying to eyeball where the frequency really is. I look at my frequency plot and remove outliers visually. After that I beat on the data with various statistical analyses, e.g. arithmetic mean and standard deviation, RMS, linear regression, anything I can think of to give me a better picture of what the ionosphere is doing. In the end, I come up with an answer whose accuracy surprises me given all that noise in the data. It is a very cool thing. The FMT is *THE* contest for the serious radio geek like me. -- Brian Lloyd, WB6RQN/J79BPL 3191 Western Dr. Cameron Park, CA 95682 [email protected] +1.767.617.1365 (Dominica) +1.931.492.6776 (USA) (+1.931.4.WB6RQN) _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
