Editing Rhumb line (section)

===Spheroid===
The formulation above can be easily extended to a [[spheroid]].<ref>
{{Cite journal| doi = 10.1093/mnras/106.2.124| title = On a Problem in Navigation| journal = Monthly Notices of the Royal Astronomical Society| volume = 106| issue = 2| pages = 124&ndash;127| year = 1946| last1 = Smart | first1 = W. M.| bibcode = 1946MNRAS.106..124S| doi-access = free}}
</ref><ref>
{{Cite journal| doi = 10.1017/S0373463300045549| title = Loxodromic Distances on the Terrestrial Spheroid| journal = Journal of Navigation| volume = 3| issue = 2| pages = 133&ndash;140| year = 1950| last1 = Williams | first1 = J. E. D.| bibcode = 1950JNav....3..133W| s2cid = 128651304}}
</ref><ref>
{{Cite journal| doi = 10.1017/S0373463300010791| title = On Loxodromic Navigation| journal = Journal of Navigation| volume = 45| issue = 2| pages = 292&ndash;297| year = 1992| last1 = Carlton-Wippern | first1 = K. C. | bibcode = 1992JNav...45..292C| s2cid = 140735736}}
</ref><ref>
{{Cite journal| doi = 10.1017/S0373463300013151| title = Practical Rhumb Line Calculations on the Spheroid| journal = Journal of Navigation| volume = 49| pages = 112&ndash;119| year = 1996| last1 = Bennett | first1 = G. G.| issue = 1| bibcode = 1996JNav...49..112B| s2cid = 128764133}}
</ref><ref>
{{cite journal
|last1 = Botnev |first1 = V.A
|last2 = Ustinov |first2 = S.M.
|script-title=ru:Методы решения прямой и обратной геодезических задач с высокой точностью
|language = Russian
|trans-title = Methods for direct and inverse geodesic problems solving with high precision
|journal = St. Petersburg State Polytechnical University Journal
|volume = 3
|number = 198
|year = 2014
|pages= 49&ndash;58
|url = http://ntv.spbstu.ru/fulltext/T3.198.2014_05.PDF
}}
</ref><ref>{{ cite journal
| last = Karney
| first = C. F. F.
| year = 2024
| volume = 68
| title = The area of rhumb polygons
| journal = Studia Geophysica et Geodaetica
| issue = 3–4
| pages = 99–120
| doi = 10.1007/s11200-024-0709-z
| doi-access = free| arxiv = 2303.03219
| bibcode = 2024StGG...68...99K
}}</ref> The course of the rhumb line is found merely by using the ellipsoidal [[isometric latitude]]. In formulas above on this page, substitute the [[latitude#conformal latitude|conformal latitude]] on the ellipsoid for the latitude on the sphere.  Similarly, distances are found by multiplying the ellipsoidal [[meridian arc]] length by the secant of the azimuth.