I have questions about how fluid dynamics may be used in general, particularly flow visualisation and extraction of flow parameters. I currently use a DNS code to propagate a wake near the fluid surface (fixed), from which I extract snapshots of the surface velocity field at particular integrals which then is used as input to some remote-sensing models to simulate a radar image of the surface. I'm doing this for a simulated ship wake, and so what you see is some of the larger flow structure which is present at the surface. So, taking the instantaneous surface velocity profile, I get a snapshot of that flow/profile, analogous to a photograph. What I'm interested in is whether that snapshot of the flow/structure can be used to extract (qualitative or quantitative) information about the flow. I have to assume that no time series is available, and so whether/what information about the flow is extractable from that single snapshot image. I also have to assume that there is no other information available, apart from the length scale of the image. Any ideas? I’m sorry if this is unclear, but I’m not a fluid dynamicist and so I’m not familiar with the terminology or practices involved with CFD or flow visualisation. If you’ve any questions, please ask.