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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>How far off do they differ? Could be an issue of units I suppose.<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 can give an example of one in ArcGIS vs. PostGIS that would help a bit.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If you can also provide a sample to data you are working with that would help and your resulting query in PostGIS.<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>Amy O'Keefe<br><b>Sent:</b> Friday, November 20, 2020 11:49 AM<br><b>To:</b> PostGIS Users Discussion <postgis-users@lists.osgeo.org><br><b>Subject:</b> [postgis-users] using postgis for bathymetry data<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:black'>I have xyz bathymetry data from a port which I'm trying to calculate the volume of regions for. My results in ArcGIS always seem to differ from that in PostGIS - I have no idea which is more accurate or how each calculates its final result. I've loaded the exact same raster into postgis and use the intersect query to extract the required polygon of interest, before extruding it and then taking the volume. I'm quite new at this, so I'm afraid I'm going the wrong way about it </span><span style='font-family:"Calibri",sans-serif;color:black'><o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:7.5pt;font-family:"Calibri",sans-serif'><br><br>This email and any attachments are confidential and intended solely for the use of the addressee and may contain information which is covered by legal, professional or other privilege. If you have received this email in error please notify the system manager at <a href="mailto:postmaster@ulster.ac.uk">postmaster@ulster.ac.uk</a> and delete this email immediately. Any views or opinions expressed are solely those of the author and do not necessarily represent those of Ulster University. <br>The University's computer systems may be monitored and communications carried out on them may be recorded to secure the effective operation of the system and for other lawful purposes. Ulster University does not guarantee that this email or any attachments are free from viruses or 100% secure. Unless expressly stated in the body of a separate attachment, the text of email is not intended to form a binding contract. Correspondence to and from the University may be subject to requests for disclosure by 3rd parties under relevant legislation. <br><b>The Ulster University was founded by Royal Charter in 1984 and is registered with company number RC000726 and VAT registered number GB672390524.The primary contact address for Ulster University in Northern Ireland is Cromore Road, Coleraine, Co. Londonderry BT52 1SA</b> </span><o:p></o:p></p></div></div></body></html>