The 12MW project with the full title ‘12 MW wind turbines: the scientific basis for their operation at 70 to 270 m height offshore’ has the goal to experimentally investigate the wind and turbulence characteristics between 70 and 270 m above sea level and thereby establish the scientific basis relevant for the next generation of huge 12 MW wind turbines operating offshore. The report describes the experimental campaign at the Horns Rev offshore wind farm at which observations from Doppler Laser LIDAR and SODAR were collected from 3 May to 24 October 2006. The challenges for mounting and operating the instruments on the transformer platform at Horns Rev were overcome by a close collaboration between DONG energy and Risoe National Laboratory DTU. The site is presented. In particular, three tall offshore meteorological masts, up to 70 m tall, provided a useful source of meteorological data for comparison to the remotely sensed wind and turbulence observations. The comparison showed high correlation. The LIDAR and SODAR wind and turbulence observations were collected far beyond the height of the masts (up to 160 m above sea level) and the extended profiles were compared to the logarithmic wind profile. Further studies on this part of the work are on-going. Technical detail on LIDAR and SODAR are provided as well as theoretical work on turbulence and atmospheric boundary layer flow. Selected results from the experimental campaign are reported.