Aiming at problem of poor positioning precision and high computational complexity of approximate point-in-tetrahedron（ APIT） positioning algorithm for WSNs

an APIT centroid localization algorithm for WSNs based on half of RSSI value（ APIT—HR） is proposed. This algorithm uses the unknown node and two anchor nodes of triangular to sense RSSI value of the third anchor node of triangular at the same time

and compare those RSSI values to treat the centroid of possibility area of unknown node as positioning coordinates. this algorithm also improves some defects of original APIT algorithm by using area rules and circle cross-domain centroid algorithm.Simulation results show that

compared with the original APIT algorithm

APIT—HR algorithm reduces computational complexity

improves positioning coverage rate and positioning precision

and positioning error of APIT—HR is reduced by 22. 8 %.