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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 am currently using GDAL 3.1.3 and Mapserver 7.6.2 on a Ubuntu machine. I created a layer using a GRIB2 file as the source data.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When I tested the layer on QGIS 3.20, I noticed that it does not output correctly. When I’m zooming or moving the viewing extent to visualize the layer or data, the style constantly changes. I tested with WMS GetMap requests through a browser
and the output issue is still there. See example GIF here: <a href="https://pasteboard.co/wAmyAUDyEeZs.gif">
https://pasteboard.co/wAmyAUDyEeZs.gif</a> <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I validated the different classes (CLASS) in the style used in the mapfile and everything seems to be in order. From what I understand, Mapserver seems to do some interpolation, but I can’t quite understand how it affects the output on
that scale. I investigated and checked if the source file was the issue, but from what I see it doesn’t seem like it’s the case, as I tested with other data from another source file in NetCDF, and the issue is still there.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I created a test case to show you the issue here:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span lang="FR-CA" style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="FR-CA">Sample mapfile: <a href="https://pastebin.com/KC3UkR4m">
https://pastebin.com/KC3UkR4m</a><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA"><o:p> </o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>GRIB2 Source file (available here: <a href="https://dd.weather.gc.ca/model_hrdps/continental/grib2/00/001/">
https://dd.weather.gc.ca/model_hrdps/continental/grib2/00/001/</a>) for the source data (using following patterns) : /CMC_hrdps_continental_PTYPE_SFC_0_ps2.5km_*.grib2/<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Do you have an idea what could be the issue or how the interpolation works, and how to solve this issue?
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks a lot in advance for your answer(s)!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="FR-CA">Félix Laframboise<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Félix Laframboise, B.Sc.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Développeur géospatial / Geospatial developer<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Systèmes de données géospatiales et ouvertes<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Geospatial and Open Data Systems<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Service Météorologique du Canada<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Meteorological Service of Canada<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR-CA" style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Environnement et Changement Climatique Canada<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA">Environment and Climate Change Canada<o:p></o:p></span></p>
<p class="MsoNormal"><a href="mailto:felix.laframboise@ec.gc.ca"><span style="font-size:10.0pt;font-family:"Courier New";color:blue;mso-fareast-language:EN-CA">felix.laframboise@ec.gc.ca</span></a><span style="font-size:10.0pt;font-family:"Courier New";mso-fareast-language:EN-CA"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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