A multi-stage process utilizes one or more sensors, including radiation sensors, on a distributed network for the detection and identification of radiation, explosives, and unauthorized hazardous materials within a shipping container. The sensors can be configured as nodes on the network. The system collects data, such as radiation data, from one or more sensors. The system spectrally analyzes the collected radiation data. The system identifies one or more isotopes based on the spectrally analyzed radiation data. A central monitoring station can monitor radiation data received from the sensors. Communication of sensor data can be done using TCP/IP communication over the network.