7. The mobile body track identification system according to claim 2 , wherein the likelihood calculation part further includes a track-coupling likelihood calculation part that is configured to calculate a track-coupling likelihood representing a likelihood of connecting tracks included in each of track-coupling candidates in track-coupling candidate/identification pairs ascribed to each of the selected hypotheses, and wherein the most-probable estimation part is further configured to estimate the most-probable hypothesis based on identification likelihoods and track-coupling likelihoods of hypotheses.
2. The mobile body track identification system according to claim 1 further comprising a map storage that is configured to store a probability map defining detection probabilities of identifications of mobile bodies in response to positional coordinates of mobile bodies in the tracking area in advance, wherein the likelihood calculation part includes an identification likelihood calculation part which is configured to specify a position of a mobile body on tracks indicated by each track-coupling candidate at each identification detection time for each track-coupling candidate/identification pair ascribed to each of the selected hypotheses, to read a probability value of detecting the mobile body at the position from the probability map, to calculate an identification likelihood based on the probability value, to integrate identification likelihoods for each track-coupling candidate/identification pair so as to calculate an identification likelihood regarding each of the selected hypotheses, and a most-probable estimation part that is configured to estimate the most-probable hypothesis based on identification likelihoods of hypotheses.