HIGH ACCURACY PIPELINE DEPTH OF COVER SURVEY IN CHANNEL CROSSING USING INERTIAL NAVIGATION

摘要

A high accuracy pipeline position survey of a ship channel crossing was performed using an in-line inertial navigation survey combined with the GPS coordinates of the channel banks. Two independent inertial surveys were performed to confirm the required accuracy of 0.6 ft (0.2m). The results were overlaid with the channel bottom profile to determine the pipeline depth of cover. It proved that the planned dredging of the channel could be performed safely without compromising the integrity of the pipeline, and the expensive removal of the pipeline was not required. In addition the in-line inertial and caliper survey provided complete geometry data for the entire 12 mile (19km) line, including bending strain, caliper information, pipe tally and NAD27 coordinates that can be used for creating GIS database and anomaly location with GPS.