1. n. [Geophysics]

The problem of determining the value or spatial variation of a physical property or feature by comparing measurements to the predictions of a model. For example, seismic traveltimes from a source to a receiver can be used to build a model of seismic velocity in the Earth, or earthquake arrival times can be used to determine the timing and focus (location) of an earthquake. A typical inverse problem in electromagnetics is to determine the variation of electrical conductivity in the Earth from measurements of induced electric and magnetic fields. A forward problem, in contrast, involves taking an assumed model and calculating what the observed values should be, such as the predicting seismic traveltimes between a source and a receiver given a velocity model.

See: forward problem