Drones micro-Doppler signatures obtained by FMCW radars are an excellent
procedure for malicious drone detection, identification and classification.
There are a number of contributions dealing with recorded spectrograms with
these micro-Doppler signatures, but very low number of them has analyzed
possibility to calculate echo caused by drone moving parts. In this paper,
starting from already existing mathematical apparatus, we presented such
spectrograms as a function of changing drone moving parts characteristics:
rotor number, blades number, blade length and rotor moving speed. This
development is the part of a wider project intended to prevent malicious
drone usage.