Realization of source localization with sensor selection in a wireless sensor network formed with low cost, energy efficient sensors

In a Wireless Sensor Network (WSN), system resources, such as computational resources, the total node energy, need to be utilized effectively while executing the task of interest. Since a number of sensor nodes may be needed in various type of applications, it is also important to develop each sensor node in a cost effective manner. The purpose of this thesis is to develop a custom made, low power and cost-effective wireless sensor node based on a MSP430G2553 microcontroller and nRF24L01+ wireless transceiver module. Then, using these nodes, we form a WSN, and locate the position of a source emitting light. Sensor nodes receive measurements from the light source and sensor measurements are transmitted to the fusion center based on a random access communication protocol. Under this protocol, a sensor node first compares its measurement with a specific transmission threshold. If the measurement exceeds the threshold, then it is transmitted to the fusion center. So that rather than gathering all sensor measurements at the fusion center, we only collect data from the sensor nodes which are close to the light source. Under different transmission thresholds, we obtain the Mean Squared Error (MSE) of source location estimate as a function of the number of transmitting sensor nodes. We also obtain the total number of sensor retransmissions due to collisions with respect to number of transmitting sensor nodes as the value of the transmission threshold varies. Estimates of the source location are also presented in Matlab with real time visualization.