“…The further development of sensors and application of multiple sources has fostered the modernization of the known techniques and algorithms, e.g., JPDA, Joint Probabilistic Data Association [ 15 , 16 , 17 ], as well as inventions of new ones, such as MHT, Multiple Hypothesis Tracker [ 18 , 19 , 20 , 21 , 22 ] or PHD, Probability Hypothesis Density [ 23 , 24 , 25 , 26 ]. With new sensors such as stereo video cameras, tracking smaller objects such as drones and birds has become possible.…”