Analytical formulation for the micro-Doppler spectrum for rotating targets in the near-field

The analysis of the Doppler signal returned by rotating targets is of great interest in the framework of target recognition and equipment monitoring. An analytical expression of such a signal already exists for the far-field case, based on the Jacobi-Anger expansion. An extension of this analytical expression is proposed for the near-field case. The solution involves a closed-form expression of each harmonic complex coefficient. An error analysis is carried out.