| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress an erroneous detection due to a change in measuring environment, improve the measuring accuracy and retain continuity in a displacement measuring system including a displacement measuring section 80 that measures displacement of a transmitter from a change in a phase difference of reception signals from a plurality of receivers receiving electric waves from the transmitter, and an environmental change detecting section 40 that, when a correlation coefficient of criterion data based on a previously received signal and measurement data in the displacement measurement is lower than a threshold, detects an occurrence of the change in the measuring environment. <P>SOLUTION: The displacement measuring system includes: a calibration processing section 50 configured to calibrate a phase difference due to a change in the measuring environment when the change in the measuring environment is detected; an initial calibration data section 60 for previously retaining an initial calibration; and a most recent calibration data section 70 for generating and updating most recent calibration data from a most recent observation reception signal. When detecting the change in the measuring environment, the displacement measuring system changes from the calibration data of the initial calibration data section to that of the most recent calibration data section to perform the calibration processing and calculates a reception phase difference from a combination of the reception phases of the reception signals after the calibration. <P>COPYRIGHT: (C)2013,JPO&INPIT |
