The authors would like to thank the engineers of Mayo SPPDG for their patience, feedback, and technical support; Dr. George Pan of Arizona State University and the students of his signal propagation laboratory for algorithm research and prototype code; N. Naclario, Z. Lemnios, D. Healy, D. Cochran, A. Krishnan, DARPA, and C. Hanson, SPAWAR/Code 8505, for program support.