Improved three-dimensional localization algorithm based on volume-test scan for wireless sensor networks

Aiming at the ‘in-to-out error’ and ‘out-to-in error’ caused by boundary effect in approximate point-in-triangulation test three dimension (APIT-3D) algorithm for wireless sensor networks (WSNs), which leads a bad location precession, this paper proposes an improved APIT-3D scheme based on volume-test, named volume test approximate point-in-triangulation test three-dimension (VT-APIT-3D) algorithm. By adding the advantage of comparing to the volume of the triangular pyramids in process of point-in-triangulation test (PIT) during APIT-3D, the unknown node can be accurately determined whether it is in the testing triangular pyramid or not. This method can remove the probability of the ‘in-to-out error’ and ‘out-to-in error’ in APIT-3D. Finally, the simulation results confirm that the proposed scheme has great advantage in aspects of localization accuracy in comparison with original APIT-3D scheme and relational scheme respectively.