Improved resolution by utilising an artificial transmission medium

A general method for estimating complex data samples using a complex exponential model is presented. The method takes the frequency-dependent attenuation and phase characteristics of the propagation medium into account. It is called the artificial transmission medium method (ATMM) and can be utilised both for superresolution purposes and in methods which are based on the subtraction of strong signals from measured data. In the latter case it is called the reduced ATMM. It is also shown that a simplified version of the method is analogous to the Prony method. Measurements are presented which verify the applicability of the reduced ATMM. Weak signals that are totally masked either by the main lobe or by the sidelobes of a stronger signal are resolved by utilising the reduced ATMM. The measurements also show that the reduced ATMM gives a better estimate of the reflection coefficient of a coupling loop than the model used in the Prony method