Methods and a sensor module for use in controlling operation of a gas turbine system are provided herein. The sensor module is coupled within a combustion system and is configured to obtain an aspirated exhaust sample of exhaust flowing through an exhaust duct. The exhaust is generated by the combustion system. The aspirated exhaust sample is analyzed to determine a plurality of exhaust parameters. The sensor module also controls at least one combustion system parameter in a closed loop emission control (CLEC) system based on at least one of the plurality of exhaust parameters.