Differencing of time-lapse survey data using a projection onto convex sets algorithm

Mostafa Naghizadeh, Kristopher A. Innanen

Irregular spatial sampling in time-lapse surveys can hamper the efforts to obtain optimal difference sections due to very sparse common spatial samples in the baseline and monitor surveys. We exploit the similarities between baseline and monitor surveys via a Fourier-based reconstruction methods called projection onto convex sets (POCS) to obtain a reliable difference section. Simultaneous handling of baseline and monitor surveys provides a robust indicator of dominant harmonics in the difference section for a given frequency component. Synthetic and modelled data examples demonstrate the viability of the approach when baseline and monitoring data sets have so few as 30% common trace locations.