Abstract
In order to clarify the location of projectile after penetrating into sand, an originally developed "Magnet-Coil" method using electromagnetic induction was applied. It allows us the multi-point measurement of the location of a moving magnet in opaque media like sands. We have already confirmed that it has sufficient measurement accuracy in the case of straight penetration. However, in our previous experiments, it was found that the penetrating projectile meandered. Therefore, in this study, we conducted free fall experiments in consideration of eccentricity and gradient of falling object and tried to formulation of output signal of coil. As a result, theoretical equations were formulated for the output voltage induced by attitude and trajectory of the magnet.
