Masanori Sugimoto Kan Tulathimutte Toshio Ito Tetsuya Sato Hiromichi Hashizume An Ultrasonic 3D Positioning System Using a Single Compact Receiver Unit. 240-253 2009 LoCA http://dx.doi.org/10.1007/978-3-642-01721-6_15 conf/loca/2009 db/conf/loca/loca2009.html#SugimotoTISH09