1. Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, USA
2. Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
3. Air Force Research Laboratory, Sensors Directorate, Wright-Patterson AFB, Ohio 45433, USA
4. U.S. Army Research and Technology Integration Directorate, Fort Belvoir, Virginia 22060, USA