Coordinates can be calculated using satellites such as GPS, GLONASS and Galileo with known orbits. All of these systems including Compass are called GNSS. To increase the accuracy of point coordinates, the error sources of GNSS are being researched for a long time. One of these errors is the antenna phase center unknown. Due to the fact that the antenna phase center is a dynamic point, it cause an error and this error consists of antenna phase center offset and antenna phase center variations that have to be known. In this study, types of antenna calibration, specifications of an antenna calibration area and national studies on this subject are explained. Also, a study on antenna calibration network which established at Istanbul Technical University is mentioned.