Monitoring the Earth’s shortwave reflectance with persistent, sub-diurnal, cloud-resolved sampling would improve understanding of key climate system processes and track geo-engineering efforts. Current measurement systems do not provide the spatial, spectral or temporal sampling to distinguish between natural variability and anthropogenic modification, so this paper presents Low Earth O rbit (LEO ) and Geosynchronous Earth O rbit (GEO ) system architectures that provide the se monitoring capabilities. The LEO system is a constellation of sixteen microsatellites in four orbit planes with a miniature push-broom Dyson spectrometer providing a 709 km swath. The satellite is a Boeing microsat that builds on heritage of recent Boeing Space Environmental NanoSat Experiment (SENSE) mission. The GEO system is a scanning O ffner spectrometer on a constellation of six satellites launched from a single EELV class launch vehicle. Both systems provide a two hour revisit, globally, at 1 km spatial resolution and 10 nm spectral resolution between 380 nm and 2510 nm.

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