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<DIV><FONT face=Arial size=2>And miss all the fun when the Hubble mirror is out
of focus? Never</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=rikard.sohlberg@home.se href="mailto:rikard.sohlberg@home.se">Rikard
Sohlberg</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=aprssig@lists.tapr.org
href="mailto:aprssig@lists.tapr.org">aprssig@lists.tapr.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Cc:</B> <A title=jingel@skyracer.net
href="mailto:jingel@skyracer.net">'Mikael Engström'</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, August 21, 2007 5:50
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [aprssig] Another kind of
SmartBeaconing?</DIV>
<DIV><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I would like to throw out a
question. <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I use APRS for tracking gliders
(sailplanes). From humble beginnings here in <st1:country-region
w:st="on"><st1:place w:st="on">Sweden</st1:place></st1:country-region>, it has
grown into a big success, almost turning a niche sport/event into a spectator
sport. Watching a sport where the track is anywhere from 150 to
<st1:metricconverter w:st="on" ProductID="500 km">500 km</st1:metricconverter>
(when will you boys go metric… ;.) used to be a problem. Now we have some 25
trackers active in Swedish gliders, and everybody loves it. And, yes, it is
perfectly legal, even when there is no ham onboard. Of course I can’t speak
for all jurisdictions, but at least in <st1:country-region
w:st="on"><st1:place w:st="on">Sweden</st1:place></st1:country-region>, we are
OK.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Now to my problem or question. We
have tried SmartBeaconing and fixed interval beacons. Neither one serves a
glider particularly well. A glider (when it leaves to vicinity of the
airfield), typically circles in a thermal to gain altitude and then flies in a
straight line to get around the track. Tests of SmartBeaconing has shown that
it is not well suited to this kind of motion. In fact, it gives the exact
opposite of what we want, se below. Also, to have an exact fix when the glider
is <st1:metricconverter w:st="on" ProductID="200 km">200
km</st1:metricconverter> away is not needed. What is needed, though is fast
updating at the end of the track. Incredible as it may seem, many competitions
end up with the gliders chasing each other within a few meters (ehh… feet any
one…;-) apart in the race to the finish line. And that is often the case after
flying a track of, say <st1:metricconverter w:st="on" ProductID="300 km">300
km</st1:metricconverter> and 3-4 hours. Speeds are typically up to
<st1:metricconverter w:st="on" ProductID="250 km/h">250
km/h</st1:metricconverter> (mph..?) at the race for the finish
line.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">So after this wordy preamble… What
I see needed is some kind of Geofence/box-type beaconing.
<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">The algorithm being something
like:<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">If (tracker.lat<N60.5 and
tracker.lat >59.8 and tracker.long<E16.5 and tracker.long>15.9) then
beacon every 10 secs<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">If (tracker.distance-to-goal-line
< <st1:metricconverter w:st="on" ProductID="5 km">5
km</st1:metricconverter>) beacon every 2 secs<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> Else<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Beacon every 3
minutes<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I’m not a programmer (any more),
but you are clever guys, you get my idea. When inside the box (including the
starting gate and finish line) beacon often, outside the box fall back to once
every 3 min or so not to clutter up the QRG. <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Does anyone know of some tracker
code/application for this?<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Of course, what would also be
handy would be a Glider specific mode:<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">If(course .changes. more than 15
seconds) stop beaconing ./ When entering a thermal and
starting to circle /.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">When (course .eq. last.course(15
sec))) beacon
./
When leaving the thermal and flying in a straight line
/.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Any one out there doing something
like this? <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Thanks for any thoughts and
ideas.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">73 de
SM0JWX/Rikard<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">(Go metric before
<st1:country-region w:st="on"><st1:place
w:st="on">Burma</st1:place></st1:country-region>,
please…)<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN lang=EN-GB
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P></DIV>
<P>
<HR>
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