Sinusoidal Projection

$\begin{figure}\begin{center}\BoxedEPSF{maps/sinu.epsf scaled 600}\end{center}\end{figure}$

An equal Area Map Projection.

$\displaystyle x$	$\textstyle =$	$\displaystyle (\lambda-\lambda_0)\cos\phi$	(1)
$\displaystyle y$	$\textstyle =$	$\displaystyle \phi.$	(2)

The inverse Formulas are

$\displaystyle \phi$	$\textstyle =$	$\displaystyle y$	(3)
$\displaystyle \lambda$	$\textstyle =$	$\displaystyle \lambda_0+{x\over\cos\phi}.$	(4)

References

Snyder, J. P. Map Projections--A Working Manual. U. S. Geological Survey Professional Paper 1395. Washington, DC: U. S. Government Printing Office, pp. 243-248, 1987.