<div dir="ltr">Dear Proj community, <div><br><div>i am looking at transforming data into GDA2020 MGA zone 54 : </div><div><p style="margin:0px;white-space:pre-wrap">+proj=utm +zone=54 +south +ellps=GRS80 +units=m +no_defs +type=crs</p><p style="margin:0px;white-space:pre-wrap"><br></p><p style="margin:0px;white-space:pre-wrap">But it seems this projection is associated with a transformation grid</p><p style="margin:0px;white-space:pre-wrap"><a href="https://www.icsm.gov.au/datum/gda-transformation-products-and-tools/transformation-grids">https://www.icsm.gov.au/datum/gda-transformation-products-and-tools/transformation-grids</a><br></p><p style="margin:0px;white-space:pre-wrap"><br></p><p style="margin:0px;white-space:pre-wrap">I have therefore dowloaded the corresponding .gsb transformation files</p><p style="margin:0px;white-space:pre-wrap"><a href="https://github.com/icsm-au/transformation_grids">https://github.com/icsm-au/transformation_grids</a><br></p></div><div><br></div><div>However when I apply the transformation, it appears the process does not use the transformation files and generate data with planimetric and vertical offsets.</div><div><br></div><div>How can I make sure the transformation grid are applied and what file makes the link between proj code and transformation files - is this stored in proj.db ? </div><div><br></div><div>Thanks for your help !</div><div>Best regards, </div><div><br></div><div>Pierre C</div></div></div>