Completed steps towards the stated goal

Any iterative inversion process is built on three cornerstones: 1. The ability to transform a guess of the solution from the initial domain to a domain where an anomaly can be extracted; 2. The ability to extract the anomaly in this latter domain by comparing the result of the transformation of the initial guess against a set of criteria; and 3. The ability to transform the extracted anomaly back to the initial domain, updating the guess. In the particular case of the inversion we are setting up, the discrimination domain is the angle domain. We will further prove point 1 above: that the FEAVO anomalies are visible in the angle domain (that the common downward continuation followed by transformation from the offset to angle does not destroy them). We will also discuss point 2 (the various methods for extracting the FEAVO anomalies in the angle domain) but will leave an example of the actual extraction to a future paper. Because of time constraints, point 3 (proving that the linearized downward continuation does not spoil the anomalies) is also left for a future paper.