Determination of Aircraft Pressure Altitude and Ambient Temperature using Fluorescence and Rayleigh Scattered Radiation from a Continuum Source

A new concept in non-intrusive pressure and temperature measurements for use onboard aircraft is described. The technique is based upon a combination of Rayleigh scattering and fluorescence using the Schumann-Runge system of oxygen. A functional description of the apparatus is provided along with theoretical descriptions of its performance. A numerical model for prediction of performance is described. The results of flight tests are presented which demonstrate the sensitivity of the technique to changes in both temperature and pressure.