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<div class="moz-cite-prefix">On 30/11/20 8:45 am, Andrea Mazzoleni
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAGKKSfUmyj2W6eHiU9u1fWY41oqZiaVVxRZZLzkQRoe+yt5dqA@mail.gmail.com">
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<div><span class="gmail-gI"><span></span></span></div>
<div><span class="gmail-gI"><span>Hi,</span></span></div>
<div><span class="gmail-gI"><span><br>
</span></span></div>
<div><span class="gmail-gI"><span>I bought a tracking device
that supports GPS dualband (also called dual frequency)
for high precision mapping, and I'm wondering if I can put
this information in the "source" tag.<br>
</span></span></div>
<div><span class="gmail-gI"><span><br>
</span></span></div>
<div><span class="gmail-gI"><span>The intention is to make
future mappers consider the device precision when doing
corrections.<br>
</span></span></div>
</div>
</blockquote>
<p>Sigh.</p>
<p>If the intention is to indicate the error/accuracy/uncertainty
then tag/state that. The better GPS devices give indications of
this error/accuracy/uncertainty.</p>
<p>As the error/accuracy/uncertainty varies with the topography,
satellites presently in view and the capabilities of the GPS
device a statement of the GPS device capabilities revel little
about the actual on the ground situation at the time of survey.
Some of these error/accuracy/uncertainty can be reduced by taking
many GPS tracks over several days/week/months and obtaining an
average that excludes outliers. If possible take tracks of home
to/from work and compare them to see how much they vary day to day
... they should give an idea of problem.<br>
</p>
<p>In some locations the topography gives reflected signals that
produce false GPS tracks, in these areas imagery may well be
better than survey by consumer GPS even with dual band and many
constellations are used. <br>
</p>
<p><br>
</p>
<br>
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