マハラノビス距離によるPHS測位誤差の拠点補正法(研究)  [in Japanese] An Error Offset Method for PHS Positioning System Based on Mahalanobis Distance  [in Japanese]

Focusing on the PHS positioning service used in physical distribution of logistics, a positioning error offset method for improving positioning accuracy is proposed. The PHS system has a defect that the measurement errors are large ranging from several ten meters to several hundred meters caused by the fluctuation of radio waves by buildings around the terminal. In this research, an error offset method is developed which learns patterns of positioning results (latitude and longitude) containing errors and the highest signal strength at major logistic points in advance, and matches them with the new data measured at actual distribution processes according to Mahalanobis distance. Then the matching resolution is reduced to 1/40 of the conventional error offset method.