Use of GNSS based real-time tidal information in offshore survey applications

Date/Time:

13 Mar 2012
10:30-11:00

Location:

South Galleries

Seminar Details
High accuracy positioning has been used in the offshore community for several years and is typically based on the precise point positioning (PPP) technique which can deliver accuracies at the decimetre level or better. This has opened up the possibility of using GNSS systems to detect and estimate the variations of the actual sea level from mean sea level which results in a real-time tide observation. This paper will explore the use of PPP for real time tide determination and will present data collected in actual offshore operations showing typical performance that can be achieved. Verification has demonstrated that real-time tide observations agree with tide gauge observations by less than 10cm on average and show a standard deviation of 10-15cm. The paper will also examine how the height of the GNSS antenna on a vessel is reduced to the actual sea surface as this is essential for determining an accurate and reliable tide value. The different methodology for deriving a tide value will also be covered in addition to the different vertical references that are used in offshore operations. Pieter Toor, Raymond Wong, David Russell