Editing Geographic coordinate conversion (section)

==== Simple iterative conversion for latitude and height ====
The conversion for the latitude and height involves a circular relationship involving ''N'', which is a function of latitude:
:<math>\frac{Z}{p} \cot \phi = 1 - \frac{e^2 N}{N + h}</math>,
:<math>h=\frac{p}{\cos\phi} - N</math>.
It can be solved iteratively,<ref name=osgb>A guide to coordinate systems in Great Britain. This is available as a pdf document at
{{cite web|url=http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents |title=ordnancesurvey.co.uk |access-date=2012-01-11 |url-status=dead |archive-url=https://web.archive.org/web/20120211075826/http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents/ |archive-date=2012-02-11 }} Appendices B1, B2</ref><ref name=osborne>Osborne, P (2008). [http://mercator.myzen.co.uk/mercator.pdf The Mercator Projections] {{webarchive|url=https://web.archive.org/web/20120118224152/http://mercator.myzen.co.uk/mercator.pdf |date=2012-01-18 }} Section 5.4</ref> for example, starting with a first guess ''h''≈0 then updating ''N''.
More elaborate methods are shown below. 
The procedure is, however, sensitive to small accuracy due to <math>N</math> and <math>h</math> being maybe 10{{sup|6}} apart.<ref>[https://web.archive.org/web/20080920155754/http://www.ferris.edu/faculty/burtchr/papers/cartesian_to_geodetic.pdf R. Burtch, A Comparison of Methods Used in Rectangular to Geodetic Coordinate Transformations.]</ref><ref>{{cite journal |last1=Featherstone |first1=W. E. |last2=Claessens |first2=S. J. |title=Closed-Form Transformation between Geodetic and Ellipsoidal Coordinates |journal=Stud. Geophys. Geod. |volume=52 |issue=1 |pages=1–18 |year=2008 |doi=10.1007/s11200-008-0002-6 |bibcode=2008StGG...52....1F |hdl=20.500.11937/11589 |s2cid=59401014 |hdl-access=free }}</ref>
<!-- There are several methods that solve the equation; two are shown. -->