The goal of this project was to create a next generation, portal-based, millimeter wave imaging system. This work was performed for the Awareness and Localization of Explosives Related Threats (ALERT) Center of Excellence, funded by the Department of Homeland Security (DHS). The ever-increasing security threats at airport checkpoints around the world has produced the need for further development of Advanced Imaging Technologies (AIT). æThere are over 1,200 whole body imaging systems deployed in airports around the world that are successfully interdicting contraband. DHS is driving requirements for higher probability of detection and fewer false alarms than what is available with the current imaging systems. ALERT approached this problem by revolutionizing the millimeter wave scanner architecture and imaging algorithms to produce the highest quality images available today. æMore accurate detection of smaller threats as well as the first available material discrimination was made possible by the higher quality images and advanced processing techniques deployed by ALERT. Further funding to develop the scanner prototype to a mass producible and deployable imaging system can deliver these advances to airport checkpoints where these capabilities are so desperately needed.