Method for operating a gas turbine, the gas turbine comprising a compressor, at least a combustor (13, 16) with at least two burners (24, 25), at least a turbine (14, 17) downstream of the combustor (13, 16), and a plurality of turbine outlet temperature sensors (18, 19), the method comprising the steps of: - supplying a first fuel flow to one of the burners (24,25) of one combustor (13, 16), and supplying a second fuel flow to another one of the burners (24, 25) of the same combustor (13, 16) wherein the first fuel flow is smaller than the second fuel flow; - measuring the turbine outlet temperature of the turbine (14, 17) with the turbine outlet temperature sensors (18, 19) of the respective turbine (14, 17); - identifying turbine outlet temperature sensors (18, 19) with good data quality; and characterized by: - selecting a proper subset of turbine outlet temperature sensors (18, 19) with good data quality which is smaller than a total number of the turbine outlet temperature sensors (18, 19) with good data quality; - averaging the measured temperatures of the selected turbine outlet temperature sensors (18, 19) with good data quality to obtain a trimmed turbine outlet temperature (TAT TR); and - controlling the operation of the gas turbine with the trimmed turbine outlet temperature (TAT TR); wherein the proper subset of turbine outlet temperature sensors (18, 19) with good data quality comprises the turbine outlet temperature sensors (18, 19) with good data quality and with the highest measurement values. - supplying a first fuel flow to one of the burners (24,25) of one combustor (13, 16), and supplying a second fuel flow to another one of the burners (24, 25) of the same combustor (13, 16) wherein the first fuel flow is smaller than the second fuel flow; - measuring the turbine outlet temperature of the turbine (14, 17) with the turbine outlet temperature sensors (18, 19) of the respective turbine (14, 17); - identifying turbine outlet temperature sensors (18, 19) with good data quality; and characterized by: - selecting a proper subset of turbine outlet temperature sensors (18, 19) with good data quality which is smaller than a total number of the turbine outlet temperature sensors (18, 19) with good data quality; - averaging the measured temperatures of the selected turbine outlet temperature sensors (18, 19) with good data quality to obtain a trimmed turbine outlet temperature (TAT TR); and - controlling the operation of the gas turbine with the trimmed turbine outlet temperature (TAT TR); wherein the proper subset of turbine outlet temperature sensors (18, 19) with good data quality comprises the turbine outlet temperature sensors (18, 19) with good data quality and with the highest measurement values. - selecting a proper subset of turbine outlet temperature sensors (18, 19) with good data quality which is smaller than a total number of the turbine outlet temperature sensors (18, 19) with good data quality; - averaging the measured temperatures of the selected turbine outlet temperature sensors (18, 19) with good data quality to obtain a trimmed turbine outlet temperature (TAT TR); and - controlling the operation of the gas turbine with the trimmed turbine outlet temperature (TAT TR); wherein the proper subset of turbine outlet temperature sensors (18, 19) with good data quality comprises the turbine outlet temperature sensors (18, 19) with good data quality and with the highest measurement values.