The US Navy's FORACS program was initially developed by APL during the 1960's to provide a measure of the Fleet's ability to maintain the accuracy performance of its sensor systems. Dr. Mercer provided technical guidance for the design and continuing technical development of the US FORACS ranges, and for similar ranges in Europe that are operated by the North Atlantic Treaty Organization. One of APL's primary responsibilities has been the development and installation of underwater acoustic target systems. The ability to precisely measure the accuracy performance of sensor systems such as sonar led to the requirements for performance standards. For several years Dr. Mercer published the Navy's Accuracy Standards Manual for ASW Sensor Systems, OD 41774. In order to generate performance standards that were realistic, Dr. Mercer conducted an extensive series of at-sea sensor system evaluations at the various FORACS ranges. The FORACS effort was sponsored by the Naval Sea Systems Command.