1. A target tracking apparatus configured to track each target on the basis of an N-dimensional (N is 1 or 2) angular observation value for each target detected by each of n (n is an integer equal to or greater than 2) N-dimensional angular sensors, and an N-dimensional track for each target obtained by subjecting each of the N-dimensional angular observation values to angular tracking comprising: a first determination device configured to determine which combination of N-dimensional tracks is for the real target from combinations of N-dimensional tracks for the target; a second determination device configured to determine which combination of N-dimensional angular observation values is for the real target from combinations of N-dimensional angular observation values for the target; a determination selection device configured to analyze an observation environment for the target, select the determination of the first determination device when the observation environment is an environment other than a dense environment, and select the determination of the second determination device when the observation environment is a dense environment; and a track generation device configured to calculate distance information on the basis of a combination of N-dimensional tracks for which it is determined by the first determination device that the tracks are for the real target or on the basis of a combination of N-dimensional angular observation values for which it is determined by the second determination device that the angular observation values are for the real target, and add the calculated distance information to the N-dimensional track or the N-dimensional angular observation value for each target to thereby generate an (N+1)-dimensional track for each target.