Operational trials of Textron Systems’ Terrain Commander unattended ground sensor (UGS) system are described. Terrain Commander is a powerful new concept in surveillance and remote situational awareness. It leverages a diverse suite of sophisticated unattended ground sensors, day/night electro-optics, satellite data communications, and an advanced Windows based graphic user interface. Terrain Commander OASIS (Optical Acoustic SATCOM Integrated Sensor) provides next generation target detection, classification, and tracking through smart sensor fusion of beam-forming acoustic, seismic, passive infrared, and magnetic sensors. With its fully integrated SATCOM system using internet protocols, virtually any site in the world can be monitored from almost any other location. Multiple remote sites such as airfields, landing zones, base perimeters, road junctions, flanks, and border crossings are monitored with ease from a central location. Intruding personnel or vehicles are automatically detected, classified, and imaged. Results from early operational trials in the outback of Australia and in various locations in the US are described. Probability of detection and recognition against a wide variety of targets including personnel, military and civilian vehicles, in-shore watercraft, and low altitude aircraft are discussed. Environments include snow cover, tropical savannah, rainforest, and woodlands. Experience with alternative SATCOM systems during the trials is also touched upon.