PROBLEM TO BE SOLVED: To expand an application range by improving detection accuracy and a measurement range of Doppler imaging in comparison with prior arts.SOLUTION: A Doppler imaging system generates the same two log-step multicarrier signals as a log-step multicarrier signal which is a multicarrier signal having a plurality of frequencies arranged at an exponential function interval, couples the two log-step multicarrier signals in the front/rear inverted direction around an origin on a time axis, generates log-step multicarrier signal symmetric with respect to the origin, and transmits the signal to a target object as a transmission signal. The Doppler imaging system receives a reflection signal from the target object, and measures and images at least one of a position and a speed of the target object by performing measurement processing of Doppler imaging on the basis of the received reflection signal and the transmitted symmetric log-step multicarrier signal.
