Automatic and Online Detection of Small but Persistent Shifts in GPS Station Coordinates by Statistical Process Control

Abstract

This paper describes algorithms to detect sudden and persistent changes of small magnitude in the GPS baseline solution vectors or station coordinates. The aim of the algorithms is to monitor and control the quality of GPS measurements for critical real-time and crustal deformation applications using statistical process control. Quality control is a major problem in GPS, especially where real-time, automatic, and reliable positioning is needed, such as in the case of the GPS crustal deformation-monitoring network (GEONET) of Japan.

To monitor the quality of baseline solutions the statistical techniques of Shewhart and cumulative sum charts are implemented. GPS data from GEONET, analyzed by the National Research Institute for Earth Science & Disaster Prevention (NIED), are used to test and evaluate the process control algorithms. © 2001 John Wiley & Sons, Inc.