"In this presentation, two NASA-funded projects to improve atmospheric observations from small satellite platforms will be discussed. The Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission was selected by NASA as part of the Earth Venture-Instrument (EVI-3) program. The overarching goal for TROPICS is to provide nearly all-weather observations of 3-D temperature and humidity, as well as cloud ice and precipitation horizontal structure, at high temporal resolution to conduct high-value science investigations of tropical cyclones (TCs), including: (1) relationships of rapidly evolving precipitation and upper cloud structures to upper-level warm-core intensity and associated storm intensity changes; (2) evolution (including diurnal variability) of precipitation structure and storm intensification in relationship to environmental humidity fields; and (3) the impact of rapid-update observations on numerical and statistical intensity forecasts of tropical cyclones. The four TROPICS constellation satellites (5.4 kg each) were successfully launched into orbit on May 8 and May 25, 2023 into two orbital planes inclined at 33 degrees with 550-km altitude.  Each CubeSat comprises a Blue Canyon Technologies bus and a high-performance radiometer payload to provide temperature profiles using seven channels near the 118.75 GHz oxygen absorption line, water vapor profiles using three channels near the 183 GHz water vapor absorption line, imagery in a single channel near 90 GHz for precipitation measurements (when combined with higher resolution water vapor channels), and a single channel at 205 GHz that is more sensitive to precipitation-sized ice particles. TROPICS spatial resolution and measurement sensitivity is comparable with current state-of-the-art observing platforms. Data is downlinked to the ground via the KSAT-Lite ground network with latencies better than one hour. NASA's Earth System Science Pathfinder (ESSP) Program Office approved the separate TROPICS Pathfinder mission, which launched on June 30, 2021, in advance of the TROPICS constellation mission as a technology demonstration and risk reduction effort. The TROPICS Pathfinder mission continues to yield excellent data over 24+ months of operation and has provided an opportunity to checkout and optimize all mission elements prior to the primary constellation mission. The Configurable Reflectarray for Electronic Wideband Scanning Radiometry (CREWSR) project awarded as part of the NASA ESTO Instrument Incubator Program (IIP) will provide a demonstration of all technologies needed for a large (~2x2 m), configurable aperture to be deployed from small satellite platforms.  The system can operate near 24, 31, and 50-58 GHz with electronically scanned antenna beams, thereby eliminating any need for mechanical scanning and momentum compensation.  The system is lightweight, very low power, and is built on low-cost silicon-on-insulator parts and proven techniques for deploying rigid precision surfaces.  This presentation will overview these two projects providing history, status, and outlook."

Dr. William J. Blackwell is a laboratory fellow in the Applied Space Systems Group at MIT Lincoln Laboratory, where he leads a number of projects involving atmospheric remote sensing, including the development and calibration of airborne and space-borne microwave sensors, the retrieval of geophysical products from remote radiance measurements, and the application of electromagnetic, signal processing, and estimation theory.

Dr. Blackwell has served as associate editor of the Institute of Electrical and Electronics Engineers (IEEE) Transactions on Geoscience and Remote Sensing and the IEEE Geoscience and Remote Sensing Society (GRSS) Magazine, cochair of the IEEE GRSS Remote Sensing Instruments and Technologies for Small Satellites working group, the NASA Aqua science team, and the National Academy of Sciences Committee on Radio Frequencies. He is currently the principal investigator on the NASA TROPICS Earth Venture mission. He was previously the Integrated Program Office sensor scientist for the Advanced Technology Microwave Sounder on the Suomi National Polar Partnership launched by the National Oceanic and Atmospheric Administration (NOAA) in 2011 and the Atmospheric Algorithm Development team leader for the National Polar-orbiting Operational Environmental Satellite System Microwave Imager/Sounder.

Dr. Blackwell received the MIT Lincoln Laboratory Technical Excellence Award in 2019 for his "innovative contributions to the science and practice of environmental monitoring." He was selected as a 2012 recipient of the IEEE Region 1 Managerial Excellence in an Engineering Organization Award "for outstanding leadership of the multidisciplinary technical team developing innovative future microwave remote sensing systems." In 2009, he was presented with the  NOAA David Johnson Award for his work in neural network geophysical parameter retrievals and microwave calibration and is coauthor of "Neural Networks in Atmospheric Remote Sensing" (Artech House, 2009) and "Microwave Radar and Radiometric Remote Sensing" (Artech House, 2015). Blackwell has also been an author of more than 180 publications related to atmospheric remote sensing. He is a fellow of the IEEE and an associate fellow of the American Institute of Aeronautics and Astronautics.