Overview of the electron cyclotron emission measurements on EAST

•This paper presents an overview of the ECE diagnostics on EAST, and the topic is interesting to the ECE community.•Conventional ECE diagnostics, including radiometer systems and Michelson interferometer, on EAST have been calibrated independently.•A correlation ECE diagnostic was designed and commissioned on EAST for detecting small-amplitude, broadband Te fluctuation. Radiometer systems and a Michelson interferometer, have been operated routinely to detect the electron cyclotron emission (ECE) from EAST plasmas for diagnosing the local electron temperature. A common quasi-optical antenna placed inside the vacuum vessel is employed to collect and focus the plasma emission, and the line of sight is along a radial chord. All of the systems are located in a diagnostic room where the plasma emission is transmitted by overmoded corrugated waveguide. In situ absolute intensity calibration has been carried out for both the radiometer systems and the Michelson interferometer independently, to ensure that the ECE diagnostic provides an independent electron temperature measurement. In order to diagnose the small-amplitude electron temperature fluctuation, a correlation ECE (CECE) diagnostic has been designed and commissioned recently. The CECE diagnostic employs an independent antenna system which has improved poloidal resolution.