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<p>Hi,</p>
<p>my aim is to calculate the fitovolume of a shrub vegetation area.
To do that I calculate the DSM, classify a point cloud with ground
(2) and low vegetation (3) and then create a DTM.</p>
<p>I use 2 different pipelines (see below) to do that modified from
<a href="https://github.com/manaakiwhenua/pycrown/issues/18">this
post</a>. But I have 2 issues:</p>
<ul>
<li>When I calculate the difference between DSM and DTM I get
negative values</li>
<li>The pixels of the DTM are horizontally displaced with respect
to the DSM by half a pixel.</li>
</ul>
<p>Does anyone know why I am getting these negative values using
this pipelines? Is anything wrong in the pipelines I`m using?<br>
<br>
<br>
Raúl.<br>
<br>
Pipeline for DSM:<br>
<br>
[<br>
"nubeRecortadaPdal_1.laz",<br>
{<br>
"type": "filters.range",<br>
"limits":"returnnumber[1:1]"<br>
},<br>
{<br>
"type": "writers.gdal",<br>
"filename": "nubeRecortadaPdal_1_mds.tif",<br>
"output_type": "idw",<br>
"gdaldriver": "GTiff",<br>
"resolution": 0.05, <br>
"nodata": -9999,<br>
"radius": 0.07,<br>
"window_size": 50,<br>
"data_type": "float32"<br>
}<br>
]<br>
<br>
Pipeline for DTM:<br>
<br>
[<br>
"nubeRecortadaPdal_1.laz",<br>
{<br>
"type":"filters.overlay",<br>
"dimension":"Classification",<br>
"datasource":"D:/Datos/clasificadasVector.gpkg",<br>
"layer":"ndviRandomForest",<br>
"column":"Id"<br>
},<br>
{<br>
"type":"filters.range",<br>
"limits":"Classification[2:2]"<br>
},<br>
{<br>
"type": "writers.gdal",<br>
"filename": "nubeRecortadaPdal_1_mdt_ndviRf.tif",<br>
"output_type": "idw",<br>
"gdaldriver": "GTiff",<br>
"resolution": 0.05, <br>
"nodata": -9999,<br>
"radius": 0.07,<br>
"window_size": 100,<br>
"data_type": "float32"<br>
}<br>
]</p>
<br>
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