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<DIV><SPAN class=960062103-02012008>Oh-yes, and of course right after I click
send, a different set of Google search parameters turn up the following...
Who needs snow if they are pulling data from multi-path amplitudes of soil
content... I'll have to get out a broom and shovel to clear the deck
and re-run when I return from the next trip...</SPAN></DIV>
<DIV><SPAN class=960062103-02012008></SPAN> </DIV>
<DIV><SPAN class=960062103-02012008><A
href="http://www.springerlink.com/content/m76550834v2n4242/">http://www.springerlink.com/content/m76550834v2n4242/</A></SPAN></DIV>
<DIV><SPAN class=960062103-02012008></SPAN> </DIV>
<DIV><SPAN class=960062103-02012008>-Kenneth</SPAN></DIV>
<DIV><SPAN class=960062103-02012008></SPAN> </DIV>
<DIV><SPAN class=960062103-02012008></SPAN> </DIV>
<DIV><SPAN class=960062103-02012008></SPAN> </DIV>
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT
face=Tahoma>-----Original Message-----<BR><B>From:</B> dprglist-bounces@dprg.org
[mailto:dprglist-bounces@dprg.org]<B>On Behalf Of </B>Kenneth
Maxon<BR><B>Sent:</B> Tuesday, January 01, 2008 9:19 PM<BR><B>To:</B>
dprglist@dprg.org<BR><B>Subject:</B> [DPRG] Further Quandries on
GPS...<BR><BR></FONT></DIV><FONT id=role_document>
<DIV> </DIV>
<DIV><SPAN class=124190303-02012008>Hello DPRG...</SPAN></DIV>
<DIV> </DIV>
<DIV><SPAN class=124190303-02012008>Here is one for further conversation in the
"Hmmm...?" realm...</SPAN></DIV>
<DIV><SPAN class=124190303-02012008></SPAN> </DIV>
<DIV><SPAN class=124190303-02012008>It was up to a fair 8-deg today and although
there is a significant snow pack on the ground the sun was bright and the sky
was clear for a few hours so ProtoBot ventured back out into the back yard for
more GPS expiremental data gathering.</SPAN></DIV>
<DIV><SPAN class=124190303-02012008></SPAN> </DIV>
<DIV><SPAN class=124190303-02012008>This time I made sure that ProtoBot was a
full 12 ft away from the house and this time, the house does not have a
1/2"~3/4" glaze of ice hanging on it. There is however a 3/4" layer
of solid ice under the snow back that ProtoBot is sitting on. I
pulled a bonehead move and forgot to take my hand held Garmin + adapter &
extension cord out to verify the readings, however, surprisingly ProtoBot still
recorded erronous readings, like it was doing inside and in the previous outdoor
trial up along side the house.</SPAN></DIV>
<DIV><SPAN class=124190303-02012008></SPAN> </DIV>
<DIV><SPAN class=124190303-02012008>I have taken time to swap out the GPS module
/ antenna combination on ProtoBot with the spare unit that I'll be using on an
upcoming project. And given that ProtoBot's last round of testing
performed in a similar (although less drastic from an error standpoint) manner
than did the comercial Garmin unit, I still have a quandry here.
Yes, I am still wondering *IF* this could be coming from multipath off of the
ice layer. I theroise that it is not as the 10" of snow pack sitting on
top of the ice should be enough to completely disburse the energy, and
all of the sattelites reported by the module as being used in the actual
position calculation had a good signal strength reading.</SPAN></DIV>
<DIV><SPAN class=124190303-02012008></SPAN> </DIV>
<DIV><SPAN class=124190303-02012008>I don't know that anyone on this list will
have input, however it is an interesting quandry that I am working through and I
thought it might be of interest to the group, as there are others in this group
that activly use GPS on their robots.</SPAN></DIV>
<DIV><SPAN class=124190303-02012008></SPAN> </DIV>
<DIV><SPAN class=124190303-02012008>Of course I'll post futher when I get to the
bottom of the issue... </SPAN><SPAN
class=124190303-02012008>-Kenneth</SPAN></DIV>
<DIV><SPAN class=124190303-02012008></SPAN> </DIV>
<DIV><SPAN class=124190303-02012008>BTW, Ron, the package arrived, thank
you. You didn't have to return it but since you did I'll put it to good
use in the next project. (IE, you've saved me from some eBay
surfing). -Thanks...</SPAN></FONT></DIV></BODY></HTML>