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<div class="moz-cite-prefix">On 23/6/22 11:45, Alex Sims wrote:<br>
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cite="mid:ME4P282MB0839EC5FEB89A9631A12CEA7A6B59@ME4P282MB0839.AUSP282.PROD.OUTLOOK.COM">
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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’ve now got a relatively (<$100 +
postage) Mouse GPS. It is amazingly accurate. That’s the good
news.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Now I can see a whole bunch of streets,
buildings etc out by 1-5 meters as *<b>some</b>* features were
traced without correcting the image offset. Also found my
cheap GPS and an OSX machine are not a great combination. GPSD
gets confused and ends up with mojibake most times. Virtual
serial port is fine in screen, QGIS etc.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Still fun<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Alex</p>
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<p>An error of 1-5 meters ... that would be 'acceptable' at least
for most. <br>
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<p>I take it you have the GPS antenna in the centre of the street
when you state the error, trust you don't get run over? <br>
</p>
<p>If your doing this by car then you need to travel in both
directions and take the middle of the two traces. <br>
</p>
<p>Having gathered GPS tracks to and from work over some weeks they
do vary quite considerably with some 'outliers' so you need to be
very careful if you only have one trace. <br>
</p>
<p>Statistically to reduce the uncertainty at least 6 measurements
should be taken, that would be 6 in one direction and 6 in the
other direction... </p>
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<p>The newer GPS stuff uses more than one constellation of
satellites .. and that has improved the accuracy. <br>
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