METHODS AND SYSTEMS FOR DETERMINING A SYNTHESIZED ENGINE PARAMETER

In a method for determining a synthesized engine parameter of a gas turbine engine (100) an initial model parameter (305) is obtained from an onboard model (220) associated with the gas turbine engine (100). A correction factor for the onboard model (220) is determined by modifying a difference between the onboard model (220) and an aero-thermal model (210) of the gas turbine engine (100) using first and second engine parameters (302) and first and second operating conditions (304), wherein the first and second engine parameters (302) are independent from one another over an operating envelope of the gas turbine engine (100). The initial model parameter (305) is scaled by applying the correction factor thereto to obtain a corrected model parameter (330). The corrected model parameter (330) is output as the synthesized engine parameter.