• Nidhi Malhotra

This paper introduces a WSN (Wireless Sensor Networks) localization method based on ultrasonic (US) TOF (time of flight) measurements. The participants send out U.S. signals while a central location unit calculates the TDoA (Time-Difference-of-Arrival) between four U.S. sensors for the AoA (angle-of-arrival) calculus. Additionally the sensor node radio frequency (RF) transceiver makes distance measurements using TDoA (US vs. RF). This greatly increases the precision of localization because the approximate distance from triangulation suffers disproportionately from even small errors of angle. The number of outliers and variations of the measured distances and angles are reduced by several filter stages including Kalman-filtering. Such computed polar coordinates (angle / distance) are converted into a Cartesian shape and transmitted to a base station connected to a PC. The mean error and standard deviation of angle and distance measurements (1.40 ° ± 0.50 ° / 1.00 km ± 0.20 km) result in a slight mean position error of 5.21 cm and a standard deviation of 0.70 cm, respectively.

Wireless Sensor Networks, Localization; Ultrasonic, Time-of-Flight Distance, Angle Measurement.

"Ultrasonic Localization System for Wireless Sensor Networks", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.656-661, May-2019, Available :http://www.jetir.org/papers/JETIREY06125.pdf

"Ultrasonic Localization System for Wireless Sensor Networks", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp656-661, May-2019, Available at : http://www.jetir.org/papers/JETIREY06125.pdf