Résumé
This paper provides the mathematical expressions, formulated in classical trigonometric terms, that are required (i) to compute an animal's body orientations and rotations in 3D space from data acquired at high-frequency by on-board accelerometers, magnetometers and gyrometers, (ii) to relate 3D rotations to changes in 3D orientation, (iii) to represent their spherical distributions through kernel density estimation (KDE), and (iv) to reconstruct fine-scale movements. The way the huge amount of data that is acquired by these on-board devices can be more easily managed is also considered.