The aging Civil Infrastructure System (CIS) in the United States has prompted the need for more effective structural health monitoring (SHM) techniques. Global Positioning Systems (GPS) have shown great promise for SHM, as they allow the total displacement of a structure to be measured, unlike other traditional sensors (i.e. accelerometers and strain gages). However, past research efforts have shown GPS to suffer from the effects of multipath interference, greatly reducing its accuracy in urban areas. In this study, a testing program was developed in which a controlled multipath source was introduced into a GPS network to allow for the characterization and removal of this phenomenon. In addition, the GPS performance was benchmarked against two more widely accepted sensor technologies: a terrestrial positioning system (TPS) and an accelerometer, to demonstrate its utility for monitoring CIS.
Health monitoring is becoming an increasingly valuable tool for assessment of aging infrastructure in urban zones. For such applications, Global Positioning Systems (GPS) present a promising monitoring technique-one that is able to capture the total displacements of a structure. However, due to the relative infancy of this technology, there are still issues to be resolved, including the characterization and removal of multipath effects. This paper discusses the manifestation and removal of multipath errors by examining the full-scale response of a tall building to demonstrate the accuracy of high precision GPS in comparison with traditional sensors like accelerometers.