“…The methods in the first class require iteration to obtain an accurate location estimate. The most important iterative methods include Taylor-series iterative algorithm [8], constrained total least squares (CTLS) algorithm [11,28], quadratic constraint least squares (QCLS) algorithm [6,14,27,31,38], and interior-point algorithm [9,16,29]. The second category can provide explicit solutions to the target position, and typical closed-form approaches include spherical-interpolation (SI) algorithm [4], two-step weighted least squares (TWLS) algorithm [5,10,15,23,24,26,30,32,39,40], and multidimensional scaling (MDS) algorithm [25].…”