The project is set to be completed in 2013. It will consist of 48 Repower 6.15MW turbines.
The tower will feature a laser-assisted measuring system effective horizontally and vertically at up to 200-metres.
RWE head of offshore Martin Skiba said: "The new measuring tower will now be used in our project area on a permanent basis. The collected data will help us control our Nordsee Ost wind farm efficiently in the future."
The company said a 62-metre tubular steel foundation was used in the installation of the tower. This was installed at a depth of 25-metres.