Projection azimutale équivalente de Lambert — Wikipédia

${\displaystyle x=\alpha '\cos(\varphi )\sin(\lambda -\lambda _{0})}$

${\displaystyle y=\alpha '(\sin(\varphi -\varphi _{0})-\sin(\varphi _{0})\cos(\varphi )(\cos(\lambda -\lambda _{0})-1))}$

${\displaystyle \varphi =\arcsin \left({\sin(\varphi _{0})\cos c+{y\cos(\varphi _{0})\sin c \over \rho }}\right)}$

${\displaystyle \lambda =\lambda _{0}+\arctan \left({x\sin c \over \rho \cos(\varphi _{0})\cos c-y\sin(\varphi _{0})\sin c}\right)}$

${\displaystyle \rho ={\sqrt {x^{2}+y^{2}}}}$

${\displaystyle c=2\arcsin \left({1 \over 2}\rho \right)}$