</tr>
</table>
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An FMCW radar system with a sawtooth chirp modulation can only measure the target's range but not its velocity if the target is moving. For that purpose, you need a triangular wave chirp modulation as shown in the figure below:
<table>
</tr>
</table>
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A moving target causes addition frequency shifting of the echo signal due to the Doppler effect. The frequency shift due to the target's velocity is given by:
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<math> f_d = \frac{2v_r}{\lambda_0} </math>
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where v<sub>r</sub> is the relative velocity of the target with respect to the radar system and λ<sub>0</sub> = c/f is the free=space wavelength.
== Exploring FM Modulation ==