Abstract: The present invention provides a LIDAR 100 including a correlation signal generation unit 110 for generating two or more different correlation signals, a signal transmission/reception unit 130 for outputting a part of the two or more correlation signals as a transmission signal St, and receive a signal returned by reflecting from a target 140 among the output transmission signals St as a received signal Sr, a delay time adjustment unit 150 for delaying a reference signal by an appropriate delay time using the reference signal Sref, and a delay time decision unit 180 for determining whether a signal obtained by adding the received signal and the delay reference signal together has an SNR higher than a threshold, thus to determine whether the delay time delayed by the delay time adjustment unit 150 is appropriate or not, and a processing unit 190 for confirming characteristics of the target 140.