Abstract: A system and method for detecting passive devices is provided. In various embodiments, the system includes a sensor device including a sensor module, a communications module, a processor, and a memory storing instructions, that when executed by the processor, cause the sensor module to receive a passive signal broadcast by a target device, assign a signal type to the passive signal to form passive signal data, and transmit the passive signal data to a central device or cloud. The system also includes a central device or cloud configured to receive the passive signal data from the sensor device.