This manuscript introduces the OZORAM ground-based millimeter wave radiometer. The instrument is deployed to the high Arctic (79° N, 12° E) for measurements of O<sub>3</sub> in the upper stratosphere and lower mesosphere. <br><br> The publication describes the status of OZORAM in the end of 2010. OZORAM is able to provide profile information between 30 and 70 km altitude in time intervals of 1 h. <br><br> To establish applications of the data and to investigate instrumental biases, the results from September 2008 till summer 2010 are compared to O<sub>3</sub> profiles derived from measurements of two instruments onboard polar orbiting satellites, MLS onboard EOS-AURA and SABER onboard TIMED. The agreement is within 10% in the middle and upper stratosphere and 30% in the lower mesosphere. The deviation shows systematic and oscillating features which are, however, constant during the period of comparison. <br><br> The data set is therefore suitable for studies of mesospheric and stratospheric response to changes in dynamics or due to solar influences on climate.