<div dir="ltr">Dear Noel<div><br></div><div>Thanks for your explanation. So it means that <font face="arial, sans-serif">both ellipsoids have the same geocentric coordinates, and I can use Jose's instruction.</font></div>
<div><font face="arial, sans-serif">I have four columns (lats, lons, elevation, and geoid) in an ASCII file. I need to convert all these four parameters into WGS84 system.</font></div><div><font face="arial, sans-serif">How can I apply Jose's instruction? I mean how can I call c</font><span style="font-family:arial,sans-serif;font-size:13px">s2cs for different parameters? I did not know how to input these four parameters.</span></div>
<div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div><div><span style="font-family:arial,sans-serif;font-size:13px">Sorry for this type of question, I hope you do not mind.</span></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div><div class="gmail_extra"><br clear="all"><div><div dir="ltr">cleo</div></div>
<br><br><div class="gmail_quote">On Tue, Aug 19, 2014 at 8:44 PM, Noel Zinn (cc) <span dir="ltr"><<a href="mailto:ndzinn@comcast.net" target="_blank">ndzinn@comcast.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">
<div dir="ltr">
<div style="FONT-SIZE:12pt;FONT-FAMILY:'Calibri';COLOR:#000000">
<div>Cleo,</div>
<div> </div>
<div>FAQ #7 under Altimetry products in the link you provide seems to answer the
question you ask. The FTP link in that paragraph leads you to a
program <a href="http://top2wgs.pro" target="_blank">top2wgs.pro</a> that solves your problem. The program assumes dX = dY
= dZ = 0. I’ve made the same assumption myself with <font face="Times New Roman"><font face="Calibri">TOPEX/Poseidon in a different
context. Then follow Jose’s cs2cs instructions.</font></font></div>
<div> </div>
<div>Thanks for the link.</div><div class="">
<div> </div>
<div>Noel</div>
<div> </div>
<div style="FONT-SIZE:12pt;FONT-FAMILY:'Calibri';COLOR:#000000">Noel Zinn,
Principal, Hydrometronics LLC<br><a href="tel:%2B1-832-539-1472" value="+18325391472" target="_blank">+1-832-539-1472</a> (office), <a href="tel:%2B1-281-221-0051" value="+12812210051" target="_blank">+1-281-221-0051</a>
(cell)<br><a href="mailto:noel.zinn@hydrometronics.com" target="_blank">noel.zinn@hydrometronics.com</a> (email)<br><a href="http://www.hydrometronics.com" target="_blank">http://www.hydrometronics.com</a>
(website)<br></div>
</div><div style="FONT-SIZE:small;TEXT-DECORATION:none;FONT-FAMILY:"Calibri";FONT-WEIGHT:normal;COLOR:#000000;FONT-STYLE:normal;DISPLAY:inline">
<div style="FONT:10pt tahoma">
<div> </div>
<div style="BACKGROUND:#f5f5f5">
<div><b>From:</b> <a title="cleo21drakos@gmail.com" href="mailto:cleo21drakos@gmail.com" target="_blank">Cleo Drakos</a> </div>
<div><b>Sent:</b> Tuesday, August 19, 2014 3:39 AM</div>
<div><b>To:</b> <a title="proj@lists.maptools.org" href="mailto:proj@lists.maptools.org" target="_blank">PROJ.4 and general Projections
Discussions</a> </div>
<div><b>Subject:</b> Re: [Proj] Can I convert the ellipsoids using
Proj?</div></div></div>
<div> </div></div>
<div style="FONT-SIZE:small;TEXT-DECORATION:none;FONT-FAMILY:"Calibri";FONT-WEIGHT:normal;COLOR:#000000;FONT-STYLE:normal;DISPLAY:inline"><div><div class="h5">
<div dir="ltr">Dear Jose<br><br>Thanks for your answer. Can you help me how can I
make certain that both ellepsoids have the same geocentric coordinates.<br>Only
the information I am having is below under the section of How does the GLAS
ellipsoid compare with WGS 84?<br><br>
<div><a href="http://nsidc.org/data/icesat/faq.html#3_all" target="_blank">http://nsidc.org/data/icesat/faq.html#3_all</a>
<div>
<div> </div>
<div class="gmail_extra">
<div> </div>
<div>
<div dir="ltr">cleo</div></div><br><br>
<div class="gmail_quote">On Tue, Aug 19, 2014 at 6:03 AM, Jose Gonçalves <span dir="ltr"><<a href="mailto:jagoncal@gmail.com" target="_blank">jagoncal@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT:1ex;MARGIN:0px 0px 0px 0.8ex;BORDER-LEFT:#ccc 1px solid">
<div dir="ltr">
<div>Cleo<br><br>If cartesian geocentric coordinates are the same and you just
want to express them in a different ellipsoid you can do:<br><br>cs2cs -f %.9f
+a=6378136.30 +rf=298.257 +proj=latlong +towgs84=0,0,0 +to +a=6378137
+rf=298.25722356 +proj=latlong +towgs84=0,0,0<br><br></div>
<div>If there are shift and rotation you can express them in the
+towgs84.<br></div>
<div><br>Regards<br><br></div>
<div>José <br></div>
<div> </div></div>
<div class="gmail_extra"><br><br>
<div class="gmail_quote">2014-08-18 15:13 GMT+01:00 Cleo Drakos <span dir="ltr"><<a href="mailto:cleo21drakos@gmail.com" target="_blank">cleo21drakos@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT:1ex;MARGIN:0px 0px 0px 0.8ex;BORDER-LEFT:#ccc 1px solid">
<div>
<div>
<div dir="ltr">
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif">Dear guys,</div>
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif"> </div>
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif">I have the data
(latitudes, longitudes, and elevations) given in ICESat/GLAS ellipsoid. This
equatorial radius and reciprocal flattening (1/f) on this ellipsoid
are 6378136.30 m and is 298.257 respectively.</div>
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif"> </div>
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif">Now, I want to
convert my data into WGS84 ellepsoid with equatorial radius and reciprocal
flattening (1/f) of 6378137.000000 and 298.25722356 respectively.</div>
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif"> </div>
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif">Can I convert
the ellipsoids using Proj?</div>
<div style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif"> </div><span style="FONT-SIZE:13px;FONT-FAMILY:arial,sans-serif">I hope some of you
can help me.</span><span><font color="#888888"><br>
<div class="gmail_extra">
<div> </div>
<div>
<div dir="ltr">cleo</div></div></div></font></span></div>
<div> </div></div></div>
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