On the application of non-Hamiltonian unnormalized quaternions of the half-rotation in the strapdown inertial systems

The application of non-Hamiltonian unnormalized quaternions of half-rotation in strapdown inertial systems is considered in the article. Non-Hamiltonian unnormalized quaternions can be zero in contrast to the classical Hamiltonian normalized quaternion, their rates are not constant and depend on the Euler angles of final rotation.