  The spin splitting of conduction band electrons in inversion-asymmetric
InGaAs/InP quantum wells is studied by Shubnikov-de Haas measurements combining
the analysis of beating patterns and coincidence measurements in doubly tilted
magnetic fields. The method allows us to determine the absolute values of the
Rashba and linear Dresselhaus spin-orbit interaction coefficients, their
relative sign and the full Land\'e g-tensor. This is achieved by analyzing the
anisotropy of the beat node positions with respect to both polar and azimuthal
angles between the magnetic field direction and the quantum well normal. We
show that the spin-orbit interaction is dominated by a large Rashba coefficient
together with a linear Dresselhaus coefficient that is 10 $\%$ of the Rashba
coefficient. Their relative sign is found to be positive. The g-tensor is found
to have a marked out-of-plane anisotropy and a smaller but distinct in-plane
anisotropy due to spin-orbit interaction.
