Objects moving at high speed towards you will have their color shifted a little towards the blue end of the spectrum while objects moving away have colors shifted towards the red end of the spectrum. ...Objects moving at high speed towards you will have their color shifted a little towards the blue end of the spectrum while objects moving away have colors shifted towards the red end of the spectrum. A computer compares the outgoing and reflected beam to determine not only how far away the object is (from the time it takes to return), but also how fast it is moving (from the Doppler shift in frequency).
