An Improved Three-dimensional Localization Scheme based on APIT

In wireless sensor networks, location information is essential to its monitoring activities. In view of the “boundary effect” and lack of accuracy in APIT-3D, this paper proposes an improved three-dimensional localization scheme based on APIT named IAPIT-3D. In the scheme, the probability of misjudgment is reduced by adding the conditions of judgment. On one hand, the signal strength that all of the neighbor nodes receive should be compared with the one of the unknown node. On the other hand, two variables are set for comparison to determine the position of the node relative to the triangular pyramid. Furthermore, narrowing down the targeted area through “Perpendicular Median Surface Cutting” reduces the localization error. The results of simulation show that compared with APIT-3D, IAPIT-3D can improve the accuracy of localization.