Table 1: Comparison of the accuracy in different directions.

ApproachErrorNumber of landmarks RMSE
0 # 1 # 2 # 3 # 4 # 5 # 6 # 7 # 8 # 9 # 1 0 # 1 1 #

𝑥 -error 1 2 8 7 1 3 0 4 6 0 0 7 0 0 6.626965
CMI 𝑦 -error 8 6 7 7 0 1 6 0 0 5 0 0 4.654747
𝑧 -error 0 2 2 2 1 0 1 3 1 2 3 2 1.848423

𝑥 -error 2 1 2 3 9 1 2 0 1 1 0 0 1 6 0 0 10.61838
RPFM 𝑦 -error 2 0 8 2 6 1 0 0 1 3 0 0 7 4 0 0 11.08302
𝑧 -error 2 2 2 2 1 3 0 0 3 4 3 1 2.254625

RMSE: root mean square error; 𝑥 -error: error in the 𝑥 -direction; 𝑦 -error: error in the 𝑦 -direction; 𝑧 -error: 𝑧 -error in the 𝑧 -direction.