1. Center for Space Science and Engineering Research, Virginia Tech, Blacksburg, Virginia 24060, USA
2. NAVAIR, Cherry Point, North Carolina 28533, USA
3. Cubic Aerospace, Reston, Virginia 20190, USA
4. Electrical and Computer Engineering Department, Utah State University, Logan, Utah 84322, USA
5. Sensor Systems Laboratory, SRI International, Menlo Park, California 94035, USA
6. Lutron Electronics, Allentown, Pennsylvania 18106, USA