1. n. [Formation Evaluation]
Generally, a finite impulse response (FIR) filter that has been designed to transform the usually irregular vertical response functions of raw measurements into a smooth, well-behaved response function such as a Gaussian response or a Kaiser window function. The criteria for designing inverse filters can include vertical response, depth of investigation and near-field (cave effect) response. Inverse filters have been used for many years to improve the response of induction arrays.