Abstract : This report documents the performance and operational capabilities of the GEM-3 system for the Advanced UXO Detection/Discrimination Technology Demonstration at the U.S. Army Yuma Proving Ground (YPG), Yuma, AZ. The data collection effort was conducted under the Department of the Army Research and Development DOBE4 (BA4) Technical Demonstration Program. Data analysis was conducted under the Department of the Army Research and Development DOE3 (BA3) Program. The objective was to evaluate the enhancements made to the GEM-3 system. Post-demonstration analysis focused on the functionality of the sensor system, the evaluation of the noise level of the data collected, improvements in target detection and discrimination, and positioning accuracy of the system. The stability of the system was evaluated through histograms and statistical analysis of data collected during the technology demonstration. Based on findings of the characteristics of the collected data and initial work performed on target detection and discrimination, target detection and discrimination techniques were applied and evaluated.