Abstract: A remote troop movement detector comprising a common detector assembly or nister including a microphone and a seismometer together with a power supply and a transmitter circuit, formed to combine to adapt to various deployment situations. In one of its embodiments the detector canister is combined with a flotation collar and an anchor for waterborne deployment, in a second embodiment the canister is combined with a drag plate and a ballasted forward spike to form an aerodynamically stable configuration having a thin metal cone frustum intermediate the spike and the assembly for limiting and attenuating the ground penetration impact following an airdrop, and in a third embodiment the assembly is combined with a narrow tip for manual implantation.