Page 486 - Fundamentals of Radar Signal Processing
P. 486

The  expression  for N  >  1  can  be  simplified  when                           ;  both

               conditions will be true in any scenario where target detection is likely to be
               successful. The result is







                                                                                                     (6.100)

               Furthermore, Eq. (6.100) is exact when N = 1; in this case it reduces to the N =
               1  case  in Eq. (6.99).  For  the N  =  1  case, Eq. (6.81)  can  then  be  used  in Eq.
               (6.99) to write a direct relationship between P  and P  for a single sample of a
                                                                      D
                                                                               FA
               Swerling 1 target



                                                                                                     (6.101)

                     In  an  uncorrelated  fluctuation  model  such  as  the  Swerling  2  or  4  cases,
               each  of  the N samples noncoherently integrated has a different value of SNR.
               Consequently, it is appropriate to average over the SNR in the single-sample CF

               first






                                                                                                     (6.102)

               and then perform the N-fold multiplication of the averaged single-sample CF to
               get the CF of the integrated data





                                                                                                     (6.103)

                     For the Swerling 2 model specifically the exponential PDF can again be
               used for the SNR [Eq. (6.95)], applying it this time in Eq. (6.102) to arrive at






                                                                                                     (6.104)

               and thus






                                                                                                     (6.105)
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