Aiming at problem of approximate point in tetrahedron 3D（ APIT—3D） positioning algorithm for WSNs

an improved APIT—3D localization algorithm based on sphere cutting（ SC）（ APIT—SC） is proposed. The algorithm improves problem of low precision and low coverage rate of localization when distribution of nodes is uneven

it also reduces misjudgment errors of Out To In and In To Out in PIT—3D test. Computational complexity is reduced by using sphere cutting method and recurrent selection method. Simulation experimental results indicate that the positioning coverage rate is up to 91 % and positioning error is controlled about 23 % when 500 nodes are randomly deployed in 100 m × 100 m × 100 m ideal network scenarios. Compared with the APIT—3D algorithm

APIT—SC algorithm reduces the amount of computational complexity and improves the positioning precision.