# Doppler radar velocity measurement of coning bullet

This drawing qualitatively explains the results of the Doppler radar velocity measurement for the 7.62 x 51 Nato bullet from its coning motion on the descending part of the trajectory.

While the coning bullet moves its tip towards the antenna, a velocity component subtracts from the radial velocity of the CG (the antenna sees an approaching bullet axis plus a withdrawing CG) and while the bulletīs tip withdraws from the antenna, a velocity component adds to the radial bullet velocity (the antenna sees a withdrawing bullet axis and a withdrawing CG).

Thus, the oscillating nature of the measured velocity (see figure) results from a superposition of the coning motion of the bulletīs longitudinal axis and the displacement of the CG along the trajectory.