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We present results from the first year of a campaign to characterize andmonitor the optical turbulence profile at the SAAO Sutherland observing stationin South Africa. A MASS-DIMM (MultiAperture Scintillation Sensor - DifferentialImage Motion Monitor) was commissioned in March 2010 to provide continuousmonitoring of the seeing conditions. Over the first month of the campaign, aSLODAR (SLOpe Detection And Ranging) from Durham University was also installedallowing an independent verification of the performance of the MASS-DIMMdevice. After the first year of data collection, the overall median seeingvalue is found to be 1.32" as measured at ground level. The ground layer whichincludes all layers below 1 km accounts for 84% of the turbulence, while thefree atmosphere above 1 km accounts for 16% with a median value of 0.41". Themedian isoplanatic angle value is 1.92", which is similar to other majorastronomical sites. The median coherence time, calculated from corrected MASSmeasurements, is 2.85 ms. The seeing conditions at the site do show a strongcorrelation with wind direction with bad seeing conditions being associatedwith winds from the South-East.

Optical turbulence characterization at the SAAO Sutherland site