An RSSI-based location algorithm to improve location accuracy of wireless electric field measurement nodes under DC transmission line

In wireless sensor network (WSN) based total electric field measurement system under DC transmission line, automatic acquisition of sensor node position can reduce the workload of measurement effectively and improve the test efficiency. In traditional location method by received signal strength indicator (RSSI) the path loss exponent is selected by empirical values and it is easy to cause larger location error. To improve the location accuracy of sensor nodes, a new location method, in which the real-time estimation of the path loss exponent is adopted, is proposed. In the proposed method, the distances among reference nodes and the RSSI value received by unknown node are used to perform the real-time estimation of the path loss exponent and is used to estimate the distance, thus the location error can be reduced and the adaptability to different kinds of environments can be enhanced. Experimental results show that under three typical electric field measurement environments, namely the park lawn, the school playground and the electromagnetic environment test field under test line in UHVDC test base, the location accuracy by the proposed method is higher than those by other RSSI algorithms.