The objectives of the Distributed Tracking Algorithm (DTA) Study were to investigate and compare the potential benefits of three different distributed tracking methods, each developed by a different research group. Integrity Systems' first task was to develop the DTA Simulator. This simulator, an adaptation of ISI's DKF Simulator, included a multi-platform, multi-target aircraft trajectory generator; GPS/inertial navigation systems on each platform; and user-configurable target track sensors (active or passive radars) on each platform. ISI also developed a set of 24 core simulation scenarios, designed to permit parametric studies of distributed tracker performance as a function of various driving factors. In addition, ISI adapted its federated zero-reset method to the distributed tracking problem, and developed report/track association methods for use at the local (single platform) and global (cross-platform) levels. ISI tested the performance of the federated tracking method, and identified its potential advantages and disadvantages relative to a hypothetical centralized method (measurement sharing), and a commonly used but suboptimal "ad hoc" method.