Supersonic flow from a three-stream non-axisymmetric jet is visualized using time resolved schlieren photography (up to 400,000 frames per second) while pressure on the aft deck plate of the nozzle is simultaneously sampled using kulites. Time series are constructed using the schlieren photographs and conditioned to reduce the effects of signal drift where necessary. The effect of conditioning on the frequency content of the signals and the results of multiple signal cross correlations is examined. Signals constructed from individual points in a spatially down-sampled representation of the flow field are cross-correlated with a reference point, and trends in the subsequent visualization of information propagation in the flow are noted. This process is repeated for band-pass filtered signals to separate the modes of propagation of individual frequency bands.