Related by context. Frequent words. (Click for all words.) 51 infra red camera 49 tripod mounted 49 infrared beams 49 infra red cameras 48 GPSs 48 PTZ camera 48 Mars orbiters 48 staticky 47 videocam 47 stereo surround sound 47 videocamera 47 infrared cameras 47 microphones 47 sounders 46 laser rangefinder 46 spy cam 46 infrared beam 46 handheld 46 guided munitions 46 doppler 45 disembodied voices 45 reconnaissance drones 45 sattelite 45 laser designator 45 spaceborne 45 infrared 44 Gorgon Stare 44 underwater microphones 44 Synthetic Aperture Radar 44 night vision goggles 44 infrared imagery 44 RF transmitter 44 camera 44 unblinking eye 44 drones 44 SSTV 44 soundwaves 44 hydrophone 44 videocameras 44 periscopes 44 binoculars 43 soundboards 43 cameras 43 periscope 43 digital readouts 43 sensor arrays 43 telephoto lenses 43 infra red 43 stereoscopic images 43 rooftop antennas 43 transmitters 43 infrared imaging 43 morse code 43 passive sonar 43 kinescopes 43 thermal imaging 43 infrared sensors 43 aerial drones 43 packet sniffing 43 VHF radios 42 Archerfish 42 Infra Red 42 telescopic sights 42 timeshifting 42 strobe lighting 42 radar altimeter 42 seismographic 42 infrared telescopes 42 Spy satellites 42 predator drones 42 PTZ cameras 42 GPS locators 42 ambient noises 42 PSK# 42 Remote sensing 42 Rosum 42 Doppler radars 42 inertial navigation systems 42 wirelessly transmit 42 directional antennas 42 doohickeys 42 tape recorders 42 holographic images 42 hi def 41 Rivet Joint 41 eavesdroppers 41 radio transmitters 41 infrared detector 41 remotely piloted 41 homing device 41 super slo mo 41 sensor 41 birdcalls 41 inertial guidance 41 wav file 41 glow worms 41 video recorder 41 tricorder 41 GPS 41 antiaircraft guns 41 rangefinders