3.3.2.1 Euler's Angles

The angles which specify the relative orientation of the two coordinate systems are called Euler's angles. They are defined by the following rules. First a clockwise rotation around the $ z$-axis is performed. This angle is usually denoted as $ \alpha $. Then a clockwise rotation around the new $ y$-axis follows. This second angle is denoted as $ \beta $. Finally, a clockwise rotation around the new $ z$-axis finishes the transformation. The last angle is denoted as $ \gamma $. The range of these angles are determined as follows:
    $\displaystyle 0\leqslant\alpha\leqslant 2\pi,$  
    $\displaystyle 0\leqslant\beta\leqslant\pi,$ (3.39)
    $\displaystyle 0\leqslant\gamma\leqslant 2\pi.$  

S. Smirnov: