A system for radio-frequency imaging of a structural environment is disclosed, including radio devices configured to transmit radio signals and a radio imaging device configured to receive the radio signals transmitted by the radio devices. The radio signals received at some times are scattered, reflected, or attenuated by an object collocated with an active localization device. The radio signals received at other times are scattered, reflected, or attenuated by the object not collocated with the active localization device. The system can obtain an indication of a location of the active localization device and, based on the radio signals received at the times the object is collocated with the active localization device, generate a radio signature of the object associated with the location. The system can then compute a score indicative of a likelihood that the object is at the location when it is not collocated with the active localization device.