The planetary boundary layer (PBL) height is a key parameter in air quality control and pollutant dispersion. The PBL height can however not be directly measured and its estimation relies on the analysis of the vertical profiles of the temperature, the turbulences or the atmospheric composition. An operational PBL height detection including several remote sensing instruments (windprofiler, Raman lidar, microwave radiometer) and several algorithms (Parcel and bulk Richardson number methods, surface-based temperature inversion, aerosol or humidity gradient analysis) were developed and the first year of application allowed validating these various detection methods against radio sounding measurements. The microwave radiometer provides convective boundary layer heights in good agreement with the radio sounding (median bias 0.70) and allows to fully analyzing the PBL height diurnal cycle due to its smaller time granularity. The Raman lidar also leads to good results whereas the windprofiler yields some more dispersed results. Comparisons with the numerical weather prediction model COSMO-2 were also established and point out a general overestimation by the model. Finally the seasonal cycles of the daytime and nighttime PBL heights are discussed for each instrument and each detection algorithm for two stations on the Swiss plateau.