A method can include receiving seismic data of a geologic environment; receiving a background model that is a part of a partitioned model of the geologic environment; predicting reflections using the background model; determining incoherence of an offset-dependent matching filter based at least in part on the reflections and the seismic data; based at least in part on the incoherence, adjusting the background model to generate an adjusted background model; and outputting the adjusted background model.