The aim of this diploma thesis was to evaluate a precision of spatial position of chosen services from Czepos and TopNET providers. The chosen services were virtual reference station generated by MAC concept from Czepos provider and virtual reference station NVR3 from TopNET provider. Testing measurement was measured by RTK method with GNSS instrument from Leica System 1200. There were measured long-standing observations which lasts 24 hours and short observations which lasts five and twenty seconds. The short observations were measured at five points in area of Brno. Result of the thesis is comparisons of precisions in position and height.