1. A seismic survey method that comprises: determining visibility values of a target event as a function of seismic source and receiver positions, wherein said determining the visibility values of a target event includes: finding, for each of multiple simulated shots, a reflection wavefield from the target event in a seismic model; calculating, for each of multiple receiver positions, a contribution signal from each reflection wavefield; and converting each contribution signal into a source-receiver visibility value that indicates an energy intensity of a respective contribution signal; acquiring seismic data using a source-receiver geometry selected at least in part to include source and receiver positions associated with visibility values above a threshold; and imaging the target event based on the acquired seismic data.