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Fast-response Pressure Sensitive Paint (PSP) measurements were performed on hemispherical models at transonic flow speeds. Both Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) were used to analyze the spatially and temporally resolved data. POD was used to isolate the dominant behavior in the data and isolate the dominant frequencies by looking at the temporal coefficient spectra. DMD was then used to further investigate specific frequencies. At St = 0.15-0.2, previously investigated "wake breathing" and "wake shifting" modes were found. These modes represent large spanwise symmetric and antisymmetric structures, respectively. Further, at St = 1 and St = 2, DMD showed that the wake of the turret was dominated by smaller convecting structures. The DMD modes were used to estimate the convective velocity in the wake, which was found to be relatively constant across various Strouhal Numbers.

Point pressure measurements were performed on a hemisphere-on-cylinder turret in-flight and in the wind tunnel at the University of Notre Dame. Measurements were performed at a total of 36 different locations on the turret. The pressure coefficients (c p) was analyzed versus viewing angle for each Mach number and were compared with previous experiments and theoretical values based on the potential flow. At transonic Mach numbers, the dominant frequencies of the motion of the local shock over the turret were investigated. The turret wake was also investigated and it was shown that the "smiles" cutouts and the local shock can have a "regularizing" effect of decreasing higher frequency fluctuations while increasing low frequency fluctuations. Unsteady forces acting on the turret were computed from the pressure fields and their dependence on the Mach number and turret geometry was discussed.