The Small Business Innovation Research (SBIR) Phase II project investigates a novel approach for directly measuring critical combustion flow-field information required for active control to increase combustion efficiency and reduce harmful emissions. Combustion control systems can be based on non-intrusive in-situ measurement using passive optical probes that measure spectrally-resolved radiation from specific molecular products (H2O, CO, and CO2) in the hot flow field. Concentrations and temperatures can be directly determined from the observed spectral structure. The critical innovation in this proposal is the experimental determination of the functional relationship using spectral sensor technology and tomographic reconstruction techniques. Flow field characterization is achieved using a large number of measurements over multiple lines of sight through the flow. <br/><br/>The proposed Phase II research lays the scientific ground work for active control systems for a range of multi-burner combustors, including turbine engines, boilers, and process burners. These applications represent more than 50% of the global fossil energy usage; thus improvements in efficiency can have a major economic and societal impact. The proposed innovation is just one of the component technologies required for the development of active control systems, but it is an enabling component, with potential application in all industrial combustion markets