1. A method for controlling a gas turbine engine with an engine model, the engine comprising multiple cans, the method comprising: obtaining operating frequency information associated with multiple cans of the engine; determining variation between operating frequency information of at least two cans; based at least in part on the variation, determining a median value; inputting the median value to an engine model, wherein based at least in part on the median value, the engine model determines an engine control action; and outputting a control command to implement the engine control action.