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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Siddarth,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Do you know what spatial reference system your raster data is in?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Do this:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>SELECT ST_AsText(rast::geometry), ST_SRID(rast)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>FROM your_raster_table LIMIT 1;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>You should see coordinates that resemble your geometry data (and all the coordinates should be less than 180) and srid should be 4326.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If you see big numbers, then your raster DEM is not in long lat. If the srid reads something other than 4326, then your data is not in WGS long lat, but good news is that is fine.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Figure out what SRID it’s in – might need to read the data source you got it from.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If your raster data is not in long lat, transform your geometry data to the same spatial ref sys.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>SELECT ST_Value(rast,1, p.geom)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>FROM your_raster_table AS r INNER JOIN (SELECT ST_Transform( ST_SetSRID( ST_Point(long,lat), 4326) , <srid of raster>) <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'> AS geom) AS p ON r.rast && p.geom;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> postgis-users [mailto:postgis-users-bounces@lists.osgeo.org] <b>On Behalf Of </b>Siddarth Madala<br><b>Sent:</b> Thursday, June 24, 2021 12:33 PM<br><b>To:</b> PostGIS Users Discussion <postgis-users@lists.osgeo.org><br><b>Subject:</b> Re: [postgis-users] OSM and US DEM in PostGIS<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>I have loaded the OSM data and uploaded the rasters into the database. However I cannot find a way to query all data within a radius of a (long, lat) coordinate pair while seeding each returned part of the data with its corresponding elevation value from the rasters. Any query with ST_DWithin or similar does not return any rows even though the database is populated. It could be a projection issue. If you would be able to point me in the direction of any tutorials/walkthroughs of how to do this, I would appreciate it.<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Sun, Jun 20, 2021 at 9:45 PM James Keener <<a href="mailto:jim@jimkeener.com" target="_blank">jim@jimkeener.com</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><div><p class=MsoNormal>Can you explain the issue you're having and what you've tried? I've loaded the DEM data into postgis before and have been able to query it and use it in QGIS.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Jim<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Sun, Jun 20, 2021 at 3:57 PM Siddarth Madala <<a href="mailto:sidmadala@gmail.com" target="_blank">sidmadala@gmail.com</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><p class=MsoNormal>I was looking for some assistance with the following problem. My use case of PostGIS is to store the United States' OpenStreetMap (OSM) data. This is a solved problem with a significant amount of documentation available. However, my use case differs in that I want to add US DEM elevation rasters to the database to enable my application to query and receive a graph seeded with these elevation values depending on my users' location. This problem has almost no good documentation, and most solutions are outdated or fail on my test server. Other services that provide elevation on demand are either too costly or do not provide a small enough resolution for my use case. Thus, I hope that anyone can aid me in the setup and deployment on this bespoke database.<o:p></o:p></p></div><p class=MsoNormal>_______________________________________________<br>postgis-users mailing list<br><a href="mailto:postgis-users@lists.osgeo.org" target="_blank">postgis-users@lists.osgeo.org</a><br><a href="https://lists.osgeo.org/mailman/listinfo/postgis-users" target="_blank">https://lists.osgeo.org/mailman/listinfo/postgis-users</a><o:p></o:p></p></blockquote></div><p class=MsoNormal>_______________________________________________<br>postgis-users mailing list<br><a href="mailto:postgis-users@lists.osgeo.org" target="_blank">postgis-users@lists.osgeo.org</a><br><a href="https://lists.osgeo.org/mailman/listinfo/postgis-users" target="_blank">https://lists.osgeo.org/mailman/listinfo/postgis-users</a><o:p></o:p></p></blockquote></div></div></div></body></html>