Page 164 - ITU Journal Future and evolving technologies – Volume 2 (2021), Issue 2
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ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 2





                                                                      Mr-UAVs
                                       6000
                                                                      Helicopters
                                                                      Fixed wing UAVs
                                       5000                           Small fixed wing planes
                                      Max. velocity (m/s)  4000       Cruise missiles
                                                                      Large fixed wing planes
                                                                      Fighter jets
                                                                      Birds
                                                                      Ballistic missiles
                                       3000
                                                                      Rockets & artillery
                                                                      HGVs
                                       2000
                                       1000
                                         0
                                           0    10   20    30   40    50    60   70
                                                      Length of central section (m)
                           Fig. 9 – Visualization of the length of the central section and maximum velocity of training targets.




                      Reflected laser beams
                                             Transmitted laser beams












                                      (a)

                                                                                 (b)
                   Fig. 10 – (a) Re lected laser beams to provide spatial diversity, (b) laser beam transmitted and re lected towards the source.

                                                                5.2 Localization and tracking of the target


                       ℳ =    (NB) (M (Tr) , C (Tr) ),  (15)    The (  ,   ,   ) coordinates of the intersection of the laser
                         1
                                                                beams are unique as shown in Fig. 5(a. If one or more








                                                                laser intersections are blocked by a target, the coordi‑

                      ℳ =    (LDA) (M (Tr) , C (Tr) ),  (16)    nates of the blocked intersection positions provide the lo‑
                        2





                                                                calization  of the target at  a given time instance. As the



                      ℳ =    (KNN) (M (Tr) , C (Tr) ),  (17)    target moves, the localization information is also updated
                        3
                                                                in time. The center of the target is the center position of

                       ℳ =    (RF) (M (Tr) , C (Tr) ).  (18)    the blocked laser intersections and mesh. For example in
                         4
                                                                Fig. 5(b, the center of the target is at the third blocked in‑
                                                                tersection of    = 2 laser mesh. The tracking and mapping
                                                                of the target’s trajectory are obtained as the blocked laser
          The interpolated target’s data and the classi ier models






          areusedtoestimatetheparticular class ofthetargetusing  intersection positions are updated as the target  moves.









          the prediction function given as                      The overall  SDCLT process of a target is given in Algo‑
                                                                rithm 2. In Algorithm 2 at lines 4 and 5, a detection test










                      (est,ℳ q )  =predict(ℳ , M (eval) ),  (19)  is carried out   /   G    <    to determine the presence of
                                         



                                                                a target for each steering position. Once a target is de‑




                                                                tected, the shape features of the target are extracted (that
          where    = 1, 2, 3, 4 stands for the model used, and  are provided in Table 1 . Next, the target is classi ied and
             (est,ℳ q )  is the estimated class from the    th  model. The  categorized based on the extracted features. The localiza‑
          predictions are made using the relevant predict functions  tion and tracking of the target are also carried out at dif‑
          speci ic to the models deployed.                      ferent steering positions (discussed in Section 5.2 . The

                                                                                                          )
                                                                extraction of features, classi ication, and localization, and
                                                                tracking of the target are provided at lines 6 to 9 of
                                                                Algorithm 2.
          150                                © International Telecommunication Union, 2021
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