f discussion of the possibilities obtainable with a parallel search operation. Specifically, we consider a system where the entire q cell uncertainty region is subdivided into say Np(2) equal components each containing q/N p cells with each of Np paths responsible for searching one component in parallel with the remaining Np - 1 paths. Furthermore, since the Np searches progress in parallel under a common control, at any point along the way, all Np alignment examinations must be dismissed before the search can proceed. Referring to these joint events as "global" events, if each parallel path is characterized by a detector with false alarm probability PFA and missed References detection probability B = 1 - PD, the global false alarm probability P FAg and global missed detection probability B 1 1 - PDg are given by BgB1-(Np-1)PFA = (1.308) For small PFA, (1.308) simplifies to PFAg = NPPFA (1.309) As an example of the application of the above, we consider the fixed sin- gle dwell serial PN acquisition system discussed in Section 1.2 implemented now with Np parallel search paths. For Np and q such that q/N p is still much greater than one, then to a good approximation (1.4) and (1.7) can be used to characterize the moments of the acquisition time of the parallel search system if q is replaced by q/N p, PD by PDg, and PFA by P FAg' For example, using the approximate relations of (1.309), the mean acquisition time would become - - - (1.310) Clearly, for small Np and small false alarm penalty time, the acquisition time varies approximately as an inverse linear function of the number of paths. Eventually, as Np gets large enough where the false alarm penalty dominates, no further improvement in mean acquisition time will result. The parallel search idea is obviously applicable to other forms of serial code search such as sequential detection where the improvement in perfor- mance would be obtained by similar replacements of q, PD, D, and PFA by q/Np, PDg, and PFAg, respectively, in the appropriate performance expressions