This article presents the implementation of decentralized data fusion (DDF) and cooperative control algorithms on an unmanned aerial system (UAS). We conduct a number of demonstrations with a pair of unmanned aerial vehicles (UAVs) performing an information-gathering mission, and we show that significant benefits can be achieved by enabling cooperation through the sharing of information between members of the team. The objective is to utilize the UAV team to estimate the position and velocity of a number of ground-based features. The UAVs are given some prior knowledge of the feature states and are required to gather further information above a predefined threshold. This situation models a scenario where initial information is made available from an external source (e.g., a high-flying UAV or satellite imagery), which then prompts the start of the feature-localization mission.