This proposal presents an economical instrument for making global measurements of density, temperature, and constituent concentration of rocket engine plumes. This innovative technique is based on collecting emitted flame radiation from a large number of viewing angles; the irradiance depends on the integrated effects of gas and particulate temperature and species concentration along the optical path. Using a large number of intersecting optical paths allows the resulting set of radiative transfer equations to be inverted to obtain the spatial temperature profile of the flame or plume. This emission tomography approach is appealing because, unlike conventional transmission tomography, neither probe beams nor their associated optics are required. Therefore, only simple optical access to the combustion chamber is required to implement this technique. Emission tomography can be used with both stimulated and spontaneously emitted radiation, and spectroscopic methods may be used to isolate the concentration of one or more constituents. By using two emission lines of a known species, the temperature may be extracted by a simple two color technique. Prior simulations and experiments presented here illustrate that with simple optical geometry and a single camera, the reaction zone of a diffusion flame may be accurately identified; this illustration applies equally well to temperature measurement. Iterative algorithms are necessary to account for self-absorption and refraction effects. This technique may also be applied directly to other gas phase processes. Note: no official Abstract listing exists of selected NASA Phase II SBIR projects for this year. Hence, this abstract is modified by idi from relevant Phase I data. The specific Phase II work statement and objectives may differ
