Abstract: A system and a method for monitoring a freight container are provided. The method includes the steps of generating a resonant spectrum representative of an initial condition of internal surfaces and contents of the freight container, and saving the resonant spectrum for future comparison purposes. The method further includes generating a second resonant spectrum and comparing the second resonant spectrum with the initial resonant spectrum to determine whether there has been any tampering with the freight container. The method also includes identifying the contents of the freight container and generating loading diagrams of the contents and using polarity configuration characteristics of the internal surfaces of said freight container to determine whether the contents have moved or been shifted during transport.