Abstract:

The appearance of RTK (real-time kinematic) technology equips the GNSS to be an irreplaceable role in the field of measurement.At the same time,with the update of the GPS receiver,multiple GNSS systems can now support hybrid reception and combined solution.Thus,the efficiency and precision of GNSS have been greatly improved.At present,the precision of dynamic calculation for GPS RTK has arrived at the subcentimetre level.It can be used in many high-precision measurement and construction fields,such as butt joint of submerged tube the undersea,high speed railway measurement and so on.But in the construction of high precision dynamic installation,the positioning of single GPS RTK often faces the problem of accuracy and reliability.Based on the real instance of large caisson construction of marine works undersea,the paper will bring forward a method,focusing on how to improve the accuracy and reliability of dynamic GPS,by making use of the feature of the multiple GPS observations correlation to figure out the problem of elevation accuracy.In order to achieve the purpose of safe,reliable and efficient construction of high precision installation and docking of underwater equipment.

Key words: GPS RTK, correlation, gross error, GNSS