1. A method for generating an illumination map, comprising: receiving an earth model representing one or more properties of the earth; receiving a target area in the earth model; propagating one or more wavefields from the target area to a potential seismic data acquisition region in the earth model; decomposing the propagated wavefields into one or more subsets of the propagated wavefields; creating the illumination map based on the subsets of the propagated wavefields, wherein the illumination map indicates one or more contributions of one or more synthetic source and receiver pairs for illuminating the target area in the earth model; and creating a seismic survey design based on the contributions.