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<p style="margin-top:0;margin-bottom:0">Adding on to Adam's comments:<br>
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<p style="margin-top:0;margin-bottom:0">It also helps a lot to read the paper on SMRF:</p>
<p style="margin-top:0;margin-bottom:0"><a href="https://www.researchgate.net/publication/258333806_An_Improved_Simple_Morphological_Filter_for_the_Terrain_Classification_of_Airborne_LIDAR_Data" class="OWAAutoLink" id="LPlnk50701" previewremoved="true">https://www.researchgate.net/publication/258333806_An_Improved_Simple_Morphological_Filter_for_the_Terrain_Classification_of_Airborne_LIDAR_Data</a></p>
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<p style="margin-top:0;margin-bottom:0">Which has the range of values for slope, window, elevation threshold and scaling factor that are effective for different types of areas. They can serve as good starting points for parameterizing the filter and save you
a lot of time.</p>
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<p style="margin-top:0;margin-bottom:0">Cheers,</p>
<p style="margin-top:0;margin-bottom:0">Best,</p>
<p style="margin-top:0;margin-bottom:0">Steve<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> pdal <pdal-bounces@lists.osgeo.org> on behalf of adam steer <adam.d.steer@gmail.com><br>
<b>Sent:</b> Wednesday, April 3, 2019 4:54:10 PM<br>
<b>To:</b> Silvia Franceschi<br>
<b>Cc:</b> pdal<br>
<b>Subject:</b> Re: [pdal] First steps using PDAL in osgeo4W</font>
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<div dir="ltr">Hi Silvia
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<div>Bradley will have a more precise answer about the relationship between PCL and PDAL; PDAL’s filters.pmf (
<a href="https://pdal.io/stages/filters.pmf.html#filters-pmf">https://pdal.io/stages/filters.pmf.html#filters-pmf</a>) is also an implementation of the PMF you found in PCL (Zhang et al 2003)</div>
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<div>I usually use filters.smrf: <a href="https://pdal.io/stages/filters.smrf.html#filters-smrf">https://pdal.io/stages/filters.smrf.html#filters-smrf</a> …which is is based on: <a href="https://pdal.io/references.html#pingel2013">https://pdal.io/references.html#pingel2013</a></div>
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<div>Parameters for ground extraction might need to change based on what the data contain, eg houses or large sheds or forests or a mix.</div>
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<div>It’s really worth taking the time to step through the PDAL workshop materials, I go through them all the time to find stuff even though I’ve taught the material before! </div>
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<div><a href="https://pdal.io/workshop/index.html">https://pdal.io/workshop/index.html</a><br>
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<div>…and maybe this page on constructing a ground classification pipeline will help: <a href="https://github.com/adamsteer/f4g-oceania-pdal/blob/master/workshop/3-pipelines.md">https://github.com/adamsteer/f4g-oceania-pdal/blob/master/workshop/3-pipelines.md</a></div>
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<div>Cheers</div>
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<div>Adam</div>
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-- <br>
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<div>Dr. Adam Steer</div>
<div><a href="http://spatialised.net" target="_blank">http://spatialised.net</a></div>
<div><a href="https://www.researchgate.net/profile/Adam_Steer" target="_blank">https://www.researchgate.net/profile/Adam_Steer</a><br>
<a href="http://au.linkedin.com/in/adamsteer" target="_blank">http://au.linkedin.com/in/adamsteer</a></div>
<div><a href="http://orcid.org/0000-0003-0046-7236" target="_blank">http://orcid.org/0000-0003-0046-7236</a><br>
+61 427 091 712 :: @adamdsteer</div>
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<div>I won’t turn up in a suit: <a href="http://www.spatialised.net/business-penguins/" target="_blank">http://www.spatialised.net/business-penguins/</a></div>
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