WIND TURBINES ON RADAR SYSTEMS AND MITIGATION MEASURES: THE CASE OF NGONG WIND FARM IN KENYA

Abstract

Air traffic control radar system that monitors traffic in Nairobi, Kenya and its environs is susceptible to displayclutter and false targets due to Doppler Effect caused by rotating wind turbine blades along the aviation pathways.This study aims to address the influence of wind turbines on aviation radar system along Ngong Hills. The import ofthe study lies in the potential increase of wind parks along the aviation pathways of Ngong and their influence onradar systems. The methodology adopted in determination of this influence of these wind parks was by executingArcGIS Viewshed analysis tool. The input data used was a 60 meter digital elevation model of Kenya obtained fromWorld Resources Institute. This data was re-sampled to 6 meters DEM in order to obtain the precision of higherresolution near the wind turbines. Line of sight analysis was carried out using the LoS tool in ArcGIS to determinethe visibility of objects over the surface. The results indicate that all turbines are visible to the radar but notdetected due to the distance between the radar and turbines. A map indicating wind power density and radarcoverage was also generated showing optimal wind farm setup sites. Based on this, operator guidance for radarsystem setup, optimal site for setting up turbines and observed displayed effects on radar screens were identifiedand recommended. Also it’s now easy to determine visibility of all wind turbines around Ngong Hills to the JKIAradar.