A multi-stage process utilizing one or more radiation sensors on a distributed network for the detection and identification of radiation, explosives, and special materials within a shipping container. The sensors are configured as nodes on the network. The system collects radiation data from one or more nodes. The collected radiation data is dynamically adjusted according to at least one of a plurality of background radiation data based on a determined background environment about the container. The collected and adjusted radiation data is compared to one or more stored spectral images representing one or more isotopes to identify one or more isotopes present. The identified one or more isotopes present are corresponded to possible materials or goods that they represent.