Development of the CESI focal plane and optics technology will lead to miniaturized hyperspectral and SWIR-band spectral imaging instrumentation compatible with CubeSat and other nanosat platforms. The project will implement the technology by developing a CubeSat-compatible SEMM instrument for global mapping of atmospheric methane concentrations. Specific Phase I technical objectives include: - Perform a trade study comparing the performance potential of alternate concepts for a miniaturized spectrometer with respect to the methane mapping mission. - Demonstrate that the image of a scene collected through an interferometer is a product of the scene radiance pattern with the interferogram. - Build a laboratory prototype and demonstrate enhanced detection of a multi-line molecular absorption band. - Test novel detector devises suitable for high-gain, low-noise SWIR imaging in a nanosat setting. - Develop the instrument architecture for SEMM and validate the concept analytically by a radiometric model. - Design the high sensitivity, low-noise SWIR focal plane for SEMM. The CESI project is undertaken by Wavefront LLC with the Space Dynamics Lab (SDL) collaborating as the research institution. The key personnel are the Project Manager and the Principle Investigator (from Wavefront) and the scientists (from SDL). The duration of Phase I is 12 months. During Phase II, SDL will prototype the complete CESI instrument incorporating Wavefront's novel high-sensitivity focal plane and readout over 24-month duration.