Innovative High Resolution IR Sensors

Measurement of stratospheric temperatures yields information critical to the monitoring of long-term atmospheric changes, weather forecasting, and scientific understanding of the middle atmosphere. We propose to develop a simple stratospheric temperature sounder, based on a Fabry-Perot interferometer used as a Multi-Order Etalon Sounder (MOES), measuring the emission spectrum of CO2. MOES uses the regularly spaced FPI instrument function to map a similar portion of each line onto a single detector. The addition of a kaleidoscope and cone allows the entire lineshape spectrum from several spectral lines to be recorded at one point in time by a linear array detector. Preliminary calculations show portions of the 4.3 um band of CO2 to be acceptable for an instrument resolution near 0.01 cm-1. Fluorescent emission of very narrow halfwidth at line center will have an effect on temperature retrieval using this band at the higher altitudes, but these effects can be accounted for by the combination of a deconvolution technique and a quantitative model. During Phase I, the proof-of-principle experiment and the MOES instrument will be designed. The instrument itself can be built and perhaps even flown in Phase II.