This paper presents the architecture of a middleware that provides an intelligent interoperability support to allow the integration and cooperation among Wireless Sensor Network (WSN) nodes and small Unmanned Aerial Vehicles (UAVs) implementing a surveillance system. The motivation for this study is that the cooperation among distinct types of sensor nodes to achieve common goals can notably enhance the results obtained in surveillance operations. A discussion around the requirements of such systems is also presented, supporting the design decisions and the choice of the techniques employed to develop the middleware. Finally, preliminary results are presented.