A Small Satellite Constellation of Compact, Multi-angle, Multi-Spectral Imagers for Global Observation of the Planetary Boundary Layer

Abstract:

The multi-spectral, multi-angle Compact Midwave Imaging System (CMIS) has an objective to provide high-spatial and -temporal-resolution observations of 3D cloud structures and winds in the free atmosphere and planetary boundary layer (PBL). Coincident observations of cloud radiative properties, top height, and winds are critically needed to evaluate the interactions between cloud radiative effects, local surface fluxes, and large-scale dynamics in the PBL. Better spatial and temporal sampling are needed to observe cloud radiative effects in the tropics/ subtropics and polar regions where the regional responses of PBL to cloud forcing can be significantly different. These needs require a dense, space-based constellation for multi-spectral observations to obtain more precise characterization of diverse PBL regimes. CMIS was developed under the NASA ESTO Instrument Incubator Program (IIP) as a small-size, low-weight, and low-power instrument that provides radiometrically calibrated multi-spectral, multi-angle wide-field-of-view observations in the shortwave-midwave infrared of clouds, aerosols, and other particulates. For a future space mission, CMIS will employ stereo techniques from two satellites (LEO-LEO or LEO-GEO) to derive cloud heights and atmospheric motion vectors that are free of the ambiguities in height assignment and along-track motions that are apparent in current earth-observing missions. Airborne flight tests of the new instrument are scheduled for January 2021. Initial results from ground collects at JHU/APL will be presented.