An apparatus for measuring at least one parameter associated with a fluid flowing within a pipe includes a spatial array of pressure sensors disposed at different axial locations x.sub.1. . . x.sub.N along the pipe. Each of the pressure sensors provides a pressure signal P(t) indicative of unsteady pressure within the pipe at a corresponding axial location of the pipe. A signal processor receives the pressure signals from each of the pressure sensors and determines the parameter of the fluid using pressure signals from selected ones of the pressure sensors. By selecting different pressure sensors, the signal processor can configure the array to meet different criteria. In one embodiment, the array of pressure sensors may be formed on a single sheet of polyvinylidene fluoride (PVDF) that is wrapped around at least a portion of an outer surface of the pipe. This arrangement allows a large number of pressure sensors to be quickly and economically installed.