Introduction 

Localization is an essential tool for the deployment of lowcost sensor networks for use in location-aware applications and ubiquitous networking. In a typical sensor network application each sensor node monitors and gathers local information. This local information has much more significance if it can be tied to the physical location it belongs to. In location-critical applications, such as shooterlocalization, sub-meter accuracy of 3D node locations is an absolute necessity for the correct operation of the system. 

In this project, We developed a sensor node localization method using a mobile acoustic beacon. The technique is passive in that the sensor nodes themselves do not need to generate an acoustic signal for ranging. This saves cost, power and provides stealthy operation. Furthermore, the beacon can generate much more acoustic energy than a severely resource constrained sensor node, thereby significantly increasing the range. The acoustic ranging method uses a linear frequency modulated signal that can be accurately detected by matched filtering. This provides longer range and higher accuracy than the current state-of-the-art. The localization algorithm is especially designed to work in such acoustically reverberant environment, as urban terrain. The algorithm handles non-Gaussian ranging errors caused by echoes. Node locations are computed centrally by solving a global non-linear optimization problem in an iterative and incremental fashion.

Publication 

Manish Kushwaha, Karoly Molnar, Janos Sallai, Peter Volgyesi, Miklos Maroti, Akos Ledeczi, "Sensor Node Localization Using Mobile Acoustic Beacons", The 2nd IEEE International Conference on Mobile Ad-hoc and Sensor Systems (MASS 2005), Washington DC, November 2005. [pdf]

Manish Kushwaha, "Sensor Node Localization Using Mobile Acoustic Beacons", Master’s Thesis, Department of Computer Science, Vanderbilt University, Nashville TN, August 2005. [pdf]

Software

The self-localization code developed for this project can be downloaded frome here.