Sensor Localization provides fundamental support for sensor network protocols and applications. Our study has focused on how to accurately locate sensors deployed in a practical environment, where distance measurements may have large errors because radio or ultrasound signals, the widely used measurement media, are blocked, reflected, or distracted by obstructions. To addresses these problems, I have proposed the virtual ruler approach to reduce the incorrect distances in the measurement step. I have further proposed the upper bound constraint approach in localization algorithms to eliminate incorrect distance measurements. These solutions have been evaluated in simulation as well as experiments with MICA2 sensor motes and Cricket nodes

  

• C. Wang and L. Xiao, Locating Sensors in Concave Areas, in 25th Annual Conference of the IEEE Communications Society (INFOCOM), Barcelona, Spain, April 23-29 2006.
• C. Wang, Y. Ding, and L. Xiao, Virtual Ruler: Mobile Beacon Based Distance Measurements for Indoor Sensor Localization, in 3rd IEEE International Conference on Mobile Adhoc and Sensor Systems (MASS), Vancouver, Canada, October 2006.
• C.Wang, L. Xiao, and J. Rong, Sensor Localization in an Obstructed Environment, in 1st IEEE/ACM International Conference on Distributed Computing in Sensor Systems (DCOSS), Marina del Rey, California, USA, June 2005, pp. 49-62.
• C. Wang and L. Xiao, Locating Sensors under Limited Measurement Capabilities, IEEE Networking, Vol.21 No.3, May/June 2007, pp.16-23.
• C. Wang and L. Xiao, Sensor Localization in Concave Areas, ACM Transaction on Sensor Network, Vol.4, Iss.1, February 2008.