Tomography is the reconstruction of a function from line integrals through the function.
Tomography has become a routine part of medicine, and an experimental part of earth sciences. A sound source can be placed at any depth in one well and receivers placed at any depth in another well. At the sender well, we have sender depths s , and at the receiver well, we have receiver depths g . The idea is to try to map the area between the wells. The map could be one of material velocities or one of absorptivity.