1. A method comprising: obtaining first seismic data acquired by at least one seismic sensor; and processing the first seismic data to determine a value indicative of a three-dimensional angle of incidence of a seismic event based on the first seismic data, comprising: determining a time delay between a first wave and a ghost wave formed by reflection of the first wave, and determining the three-dimensional angle of incidence based at least in part on the time delay.