responding time uncertainty to be resolved could typically be quite large. In order to represent a reasonable compromise between the time required to search through this code phase uncertainty region and the accuracy within which the final alignment position is determined, the amount by which the local PN code generator is stepped in position as the search proceeds must be judiciously chosen. It is typical in practice to require that the received and local PN code signals be aligned to within one- half a code chip period (T/2) before relinquishing control to the fine syn- chronization (tracking) system. In accordance with this requirement, the time delay of the local PN code signal would be retarded (or advanced) in discrete steps of one-half a chip period and a check for acquisition made after each step. Thus, if T = NuT is the time uncertainty to be resolved, then q = 2N would be the number of possible code alignments (in serial search parlance, these are referred to as cells) to be examined during each search through the uncertainty region. In the more general case where the local code update size is arbitrary, we shall still use q to denote the num- ber of cells to be searched. The time to acquire, TACQ, i.e., the time to declare a true hit, is a random variable and, in general, depends on the initial (at the beginning of the search) code phase position of the local PN generator relative to that of the received code. The most complete statistical description of this random vari- able would be given by its probability density function, whose determina- tion would ultimately allow computation of the probability of successful synchronization for the single dwell serial synchronization system. Although the probability of successful synchronization provides the most complete sta- tistical description of system performance, one is often content with mea- suring performance in terms of the first two moments of the probability density function of TACQ, namely, the mean acquisition time, TACO, and the acquisition time