<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<div class="moz-cite-prefix">On 4/13/2024 1:26 PM, Javier Jimenez
Shaw wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CADRrdKuUTakXNL0srxBBEu4QAFB+6BBsLHM8R7ynf9ZO-GwZJw@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr"><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sat, 13 Apr 2024 at
17:35, Stephen Woodbridge via gdal-dev <<a
href="mailto:gdal-dev@lists.osgeo.org"
moz-do-not-send="true" class="moz-txt-link-freetext">gdal-dev@lists.osgeo.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Thanks, this is NOT the standard Web Mercator
projection. I am aware of EPSG:90013 and EPSG:3857. This
projection is used with HYCOM data that I have extracted
into geotif files so that I can accurately project that
onto EPSG:3857. It took some fiddling with the values to
get to overlay visually correctly. HYCOM data is weird
in that it uses two different projections based on if
the data is above or below some latitude.<br>
</div>
</div>
</blockquote>
<div>I found something like that in the Internet. But I was
not sure it was the right one <a
href="https://polar.ncep.noaa.gov/global/about/"
moz-do-not-send="true" class="moz-txt-link-freetext">https://polar.ncep.noaa.gov/global/about/</a>
It didn't specify the projections, just a short description
as Arctic bi-polar patch north of 47N, and Mercator south of
it.<br>
</div>
</div>
</div>
</blockquote>
<br>
Yes this what is happening with the HYCOM data. The projection
definition in PROJ4 worked quite well for my case of web mapping in
mapserver.<br>
<blockquote type="cite"
cite="mid:CADRrdKuUTakXNL0srxBBEu4QAFB+6BBsLHM8R7ynf9ZO-GwZJw@mail.gmail.com">
<div dir="ltr">
<div class="gmail_quote">
<div><br>
</div>
<div>I do not know if you can specify a projection "in parts"
respect to parallel 47. Maybe in WKT2.<br>
</div>
<div><br>
</div>
<div>Where did you found those parameters for the datum and
projection? They are quite strange.</div>
<div><br>
</div>
<div>For the ellipsoid there are a few already with a similar
radius:</div>
<div><br>
</div>
<div>SELECT * from ellipsoid where semi_major_axis BETWEEN
6371000 and 6371010</div>
<div><br>
</div>
<div><span></span>
<table cellspacing="0" cellpadding="2" border="1">
<tbody>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">7035</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">Sphere</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">PROJ</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EARTH</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6371000.0</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">9001</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:right"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6371000.0</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">1</td>
</tr>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">7048</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">GRS
1980 Authalic Sphere</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">PROJ</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EARTH</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6371007.0</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">9001</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:right"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6371007.0</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">0</td>
</tr>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">ESRI</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">107047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">Sphere_GRS_1980_Mean_Radius</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">Sphere
with mean radius based on GRS80</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">PROJ</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EARTH</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6371008.7714</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">9001</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">0.0</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:right"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">0</td>
</tr>
</tbody>
</table>
</div>
<br>
<div>And datums</div>
<div><br>
</div>
<div>SELECT * from geodetic_datum where ellipsoid_code in
(7035, 7048, 107047)</div>
<div><br>
</div>
<div><span></span>
<table cellspacing="0" cellpadding="2" border="1">
<tbody>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6035</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">Not
specified (based on Authalic Sphere)</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">7035</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">8901</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">1</td>
</tr>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">Not
specified (based on GRS 1980 Authalic Sphere)</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">7048</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">8901</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">1</td>
</tr>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">ESRI</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">106047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">D_Sphere_GRS_1980_Mean_Radius</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">GRS
1980 Mean Radius Sphere</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">ESRI</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">107047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">8901</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">0</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="gmail_quote"><br>
</div>
<div class="gmail_quote">and geographic crs</div>
<div class="gmail_quote"><br>
</div>
<div class="gmail_quote">SELECT * from geodetic_crs where
datum_code in (6035, 6047, 106047)</div>
<div class="gmail_quote"><br>
</div>
<div class="gmail_quote"><span></span>
<table cellspacing="0" cellpadding="2" border="1">
<tbody>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">4035</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">Unknown
datum based upon the Authalic Sphere</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">geographic
2D</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6402</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6035</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">1</td>
</tr>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">4047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">Unspecified
datum based upon the GRS 1980 Authalic Sphere</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">geographic
2D</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6422</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">1</td>
</tr>
<tr>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">ESRI</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">104047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">GCS_Sphere_GRS_1980_Mean_Radius</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">geographic
2D</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">EPSG</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">6422</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:left">ESRI</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">106047</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:italic;font-weight:normal;background-color:rgb(255,255,255);color:rgb(192,192,192);text-align:left"><br>
</td>
<td
style="font-family:"DejaVu Sans";font-size:10pt;font-style:normal;font-weight:normal;background-color:rgb(255,255,255);color:rgb(0,0,0);text-align:right">0</td>
</tr>
</tbody>
</table>
</div>
<div class="gmail_quote"> </div>
<div class="gmail_quote">See that EPSG ones are deprecated.
(surprisingly the ellipsoid EPSG:7048 is not deprecated, but
the datum that uses it is deprecated).<br>
</div>
<div class="gmail_quote"><br>
</div>
<div class="gmail_quote">
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div> On 4/13/2024 4:19 AM, Javier Jimenez Shaw via
gdal-dev wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>If what you need is really EPSG:3857, yes, use
it.</div>
<div><br>
</div>
<div>However I have seen strange parameters on your
projection. The radius of the sphere is the
"average" 3671 km, and you set a false easting and
northing of just 4.4 km. Is that trying to correct
the radius of the sphere? I do not know why you need
that.</div>
<div><br>
</div>
<div>Bas, are they really equivalent?<br>
</div>
<div><br>
</div>
<div>In proj you can convert to WKT1 (see that I added
+type=crs):</div>
<div><br>
</div>
<div><span style="font-family:monospace">projinfo
"+proj=merc +a=6371001 +b=6371001 +lat_ts=0.0
+lon_0=0.0 +x_0=-4448 +y_0=-4448 +k=1.0 +units=m
+over +nadgrids=@null +no_defs +type=crs" -o
wkt1_gdal</span></div>
<div><br>
</div>
</div>
</blockquote>
Ok I get this adding by <span
style="font-family:monospace">+type=crs but how do I add
it to the proj database so I can access it referencing
it by something like EPSG:90014?<br>
<br>
</span></div>
</blockquote>
<div><br>
</div>
<div>
<div>Is a WKT string enough?</div>
<div><br>
</div>
<div>PROJCS["unknown",<br>
GEOGCS["unknown",<br>
DATUM["unknown using nadgrids=@null",<br>
SPHEROID["unknown",6371001,0]],<br>
PRIMEM["Greenwich",0,<br>
AUTHORITY["EPSG","8901"]],<br>
UNIT["degree",0.0174532925199433,<br>
AUTHORITY["EPSG","9122"]]],<br>
PROJECTION["Mercator_1SP"],<br>
PARAMETER["central_meridian",0],<br>
PARAMETER["scale_factor",1],<br>
PARAMETER["false_easting",-4448],<br>
PARAMETER["false_northing",-4448],<br>
UNIT["metre",1,<br>
AUTHORITY["EPSG","9001"]],<br>
AXIS["Easting",EAST],<br>
AXIS["Northing",NORTH],<br>
EXTENSION["PROJ4","+proj=merc +a=6371001 +b=6371001
+lat_ts=0.0 +lon_0=0.0 +x_0=-4448 +y_0=-4448 +k=1.0
+units=m +over +nadgrids=@null +no_defs"]]</div>
<div><br>
</div>
<div>(generated with the projinfo line from prev email)
Using a geographic CRS as described above will make it
nicer, and probably more compatible.<br>
</div>
<div><br>
</div>
<div>You can use it in QGIS for instance. I am not sure how
does it behave in a GeoTIFF, as it has some special tags.
You can try to generate the geotiff with gdal with that
WKT, and see that happens.<br>
</div>
<div><br>
</div>
<div>About adding to proj.db as EPSG:900914, I am not sure
of all the steps. But I would say that you have to create
a datum and a geographic crs (or use one of the above), in
addition to the projection (conversion, parameters, etc)
and the projected crs. And then "compile" the database.<br>
</div>
<div>Is it worth it?</div>
<div>In case you modify proj.db, instead of using EPSG, you
can create your own authority, or use "PROJ" authority. It
will be cleaner.</div>
<div><br>
</div>
</div>
</div>
</div>
</blockquote>
Ok, thanks, I think I can work with this information. I appreciate
the help. <br>
I'm also considering rewriting the extraction utility to totally
avoid using this projection. This might be the better choice long
term.<br>
<br>
Thanks,<br>
-Steve<br>
<blockquote type="cite"
cite="mid:CADRrdKuUTakXNL0srxBBEu4QAFB+6BBsLHM8R7ynf9ZO-GwZJw@mail.gmail.com">
<div dir="ltr">
<div class="gmail_quote">
<div> </div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div><span style="font-family:monospace"> Thanks,<br>
-Steve<br>
</span>
<blockquote type="cite"><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sat, 13 Apr 2024
at 06:17, Sebastiaan Couwenberg via gdal-dev <<a
href="mailto:gdal-dev@lists.osgeo.org"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">gdal-dev@lists.osgeo.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On
4/12/24 11:24 PM, Stephen Woodbridge via gdal-dev
wrote:<br>
> and was able to access it in gdal, mapserver,
postgis, etc with <br>
> "EPSG:900914"<br>
<br>
I used to do that too, but switched to EPSG:3857 its
non-deprecated <br>
equivalent. I would recommend that instead of trying
to keep using a <br>
non-standard projection.<br>
<br>
Kind Regards,<br>
<br>
Bas<br>
<br>
-- <br>
GPG Key ID: 4096R/6750F10AE88D4AF1<br>
Fingerprint: 8182 DE41 7056 408D 6146 50D1 6750
F10A E88D 4AF1<br>
<br>
_______________________________________________<br>
gdal-dev mailing list<br>
<a href="mailto:gdal-dev@lists.osgeo.org"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">gdal-dev@lists.osgeo.org</a><br>
<a
href="https://lists.osgeo.org/mailman/listinfo/gdal-dev"
rel="noreferrer" target="_blank"
moz-do-not-send="true"
class="moz-txt-link-freetext">https://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br>
</blockquote>
</div>
<br>
<fieldset></fieldset>
<pre>_______________________________________________
gdal-dev mailing list
<a href="mailto:gdal-dev@lists.osgeo.org" target="_blank"
moz-do-not-send="true" class="moz-txt-link-freetext">gdal-dev@lists.osgeo.org</a>
<a href="https://lists.osgeo.org/mailman/listinfo/gdal-dev"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://lists.osgeo.org/mailman/listinfo/gdal-dev</a>
</pre>
</blockquote>
<br>
<div
id="m_-2289715080308317683DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br>
<table style="border-top:1px solid rgb(211,212,222)">
<tbody>
<tr>
<td style="width:55px;padding-top:13px"><a
href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient"
target="_blank" moz-do-not-send="true"><img
alt="" style="width: 46px; height: 29px;"
moz-do-not-send="true" width="46"
height="29"></a></td>
<td
style="width:470px;padding-top:12px;color:rgb(65,66,78);font-size:13px;font-family:Arial,Helvetica,sans-serif;line-height:18px">Virus-free.<a
href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient"
style="color:rgb(68,83,234)" target="_blank"
moz-do-not-send="true">www.avast.com</a></td>
</tr>
</tbody>
</table>
<a
href="#m_-2289715080308317683_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"
width="1" height="1" moz-do-not-send="true"> </a></div>
</div>
_______________________________________________<br>
gdal-dev mailing list<br>
<a href="mailto:gdal-dev@lists.osgeo.org" target="_blank"
moz-do-not-send="true" class="moz-txt-link-freetext">gdal-dev@lists.osgeo.org</a><br>
<a href="https://lists.osgeo.org/mailman/listinfo/gdal-dev"
rel="noreferrer" target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br>
</blockquote>
</div>
</div>
</blockquote>
<br>
</body>
</html>