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Space-based observations of tropospheric trace species have been identified as high-priority atmospheric science measurements to be included in Earth science missions of the 21st century. Critical to such measurements are tropospheric ozone (O3) concentrations, which have been increasing and will continue to do so as levels of the precursor gases (oxides of nitrogen, methane and other hydrocarbons) necessary for the photochemical production of tropospheric O3 remain rising; such a global monitoring capability is crucial to enhance scientific understanding as well as to potentially lessen the ill-health impacts associated with exposure to elevated concentrations in the lower atmosphere. An instrument concept to enable such a measurement capability for tropospheric (and total) O3 utilizing Fabry-Perot interferometry has been developed and reported in earlier work. It involves a double-etalon series configuration Fabry- Perot interferometer (FPI) along with an ultra-narrow bandpass filter to achieve single-order operation with an overall spectral resolution of approximately .068 cm-1, sampling a narrow spectral region within the strong 9.6 micrometer ozone infrared band from a nadir-viewing satellite configuration. Current research efforts are focusing on technology development and demonstration activities to address technology drivers and other design considerations associated with this measurement concept. Most importantly, we have developed a small-scale, modular, double-etalon prototype FPI for laboratory characterization and testing. This presentation will focus on advancements made pertaining to our laboratory prototype, specifically, toward the analysis and interpretation of measured solar absorption spectra. Topics will include processing of 'measured' spectra (i.e., spectral registration and drift correction) and simulation of 'true' spectra (i.e., atmospheric assumptions and instrument transfer function modeling), as well as subsequent comparisons and findings. Future developments will focus on incorporating other key elements into the prototype instrument, performing relevant laboratory and atmospheric testing, and developing methods for calibration. These activities along with concurrent scientific studies and atmospheric field testing will serve to demonstrate overall feasibility and provide technique validation for this instrumentation and may lead to a future space-based implementation.
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