<HTML dir=ltr><HEAD><TITLE>[Proj] Geodesic distances away from the ellipsoid</TITLE>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=2>Jay,</FONT></DIV>
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<DIV dir=ltr><FONT size=2>There is an old ESSA or NOAA publication that directly addressed "The Great Ellipse" and also included all the math for hyperbolic lattice computations as well as for Rho-Rho systems. I don't remember the exact title, but it was mainly addressed to the Hydrographic Surveyor. My guess is that's exactly what you are looking for. It's somewhere in my office library on campus, but I won't get there until Monday. Call me and remind me after 10:00 AM and I'll look it up, I think I know the bookcase it's in. I'll bet John Stigant and Noel have a copy, too.</FONT></DIV>
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<DIV dir=ltr><FONT size=2>Cliff</FONT></DIV>
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<DIV dir=ltr><FONT size=2>Clifford J. Mugnier, C.P., C.M.S.<BR>Past National Director (2006-2008),<BR>Photogrammetric Applications Division</FONT><BR><FONT size=2>American Society for Photogrammetry and Remote Sensing </FONT><BR><FONT size=2>and </FONT><BR><FONT size=2>Chief of Geodesy,</FONT><BR><FONT size=2>CENTER FOR GEOINFORMATICS </FONT><BR><FONT size=2>Department of Civil Engineering </FONT><BR><FONT size=2>Patrick F. Taylor Hall 3223A</FONT><BR><FONT size=2>LOUISIANA STATE UNIVERSITY </FONT><BR><FONT size=2>Baton Rouge, LA 70803</FONT><BR><FONT size=2>Voice and Facsimile: (225) 578-8536 [Academic] </FONT><BR><FONT size=2>Honorary Life Member of the </FONT><BR><FONT size=2>Louisiana Society of Professional Surveyors </FONT><BR><FONT size=2>Member Emeritus of the ASPRS </FONT><BR><FONT size=2>Member of the Americas Petroleum Survey Group</FONT><BR><FONT size=2>======================================================</FONT><BR><A href="https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.lsu.edu/exchweb/bin/redir.asp?URL=https://email.ls" target=_blank><U><FONT color=#0000ff size=2>http://www.asprs.org/resources/GRIDS/</FONT></U></A><BR><FONT size=2>======================================================</FONT></DIV>
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<FONT face=Tahoma size=2><B>From:</B> proj-bounces@lists.maptools.org on behalf of Jay Hollingsworth<BR><B>Sent:</B> Fri 20-Mar-09 11:56<BR><B>To:</B> proj@lists.maptools.org<BR><B>Subject:</B> [Proj] Geodesic distances away from the ellipsoid<BR></FONT><BR></DIV>
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<P><FONT size=2>At the risk of asking a dumb question, do any of the geodesic<BR>algorithms allow calculation of the geodesic distance if the path is<BR>not on the ellipsoid? Like in an airplane or satellite whose path<BR>could be assumed to be a constant height above the ellipsoid?<BR><BR>Or do you have to define an ellipsoid matching the satellite orbit<BR>and use the normal equations on that ellipsoid? If so, how would you<BR>define an ellipsoid for a long airplane flight?<BR><BR>I've poked around and nothing has jumped out at me. I assume<BR>aero-engineers guys figured this out long ago....<BR><BR><BR>Jay Hollingsworth<BR><BR>Seabed Portfolio Manager and<BR>Principal Data Architect<BR>Schlumberger Information Solutions<BR>phone: 713 513 8854 fax: 713 513 2093<BR><BR>_______________________________________________<BR>Proj mailing list<BR>Proj@lists.maptools.org<BR><A href="http://lists.maptools.org/mailman/listinfo/proj">http://lists.maptools.org/mailman/listinfo/proj</A><BR></FONT></P></DIV></BODY></HTML>