RECENT PROGRESS IN SMALLSAT CONSTELLATIONS, BEAM-STEERING ARRAYS, AND COGNITIVE SENSING FOR MICROWAVE IMAGING AND SOUNDING OF THE ATMOSPHERE

W. Blackwell¹, M. Abedin², V. Chandrasekar², S. Farzana², C. Kataria¹, S. Jeon¹, R. Leslie¹, A. Milstein¹, W. Moulder¹, M. Pieper¹, S. Reising², R. Thomas²

¹MIT Lincoln Laboratory, ²Colorado State University

Three new microwave sounding technologies are leading to significant improvements in both the performance benefits and the development and operating costs of new observing systems. First, small satellite constellations, such as the NASA TROPICS mission, have demonstrated new capabilities for high-revisit sampling of tropical cyclones with observing quality that approaches (and exceeds in some cases) the current state-of-the-art sensors, and commercial follow-ons to TROPICS are now being launched that offer improved performance and reliability and utilize high-speed digital spectrometers necessary for hyperspectral microwave operation and RFI detection and mitigation. Second, large-format planar arrays, such as the Configurable Reflectarray Wideband Scanning Radiometer (CREWSR), can provide high-resolution (up to 10X better than ATMS), light weight, low power, and multiband (23, 31, and 50-58 GHz) hyperspectral operation with electronically steerable beams that can operate independently in each band. CREWSR is designed to be fielded on an ESPA-class small satellite platform, and an upcoming high-altitude, long-duration balloon test flight will validate performance. Third, we consider the observing system as comprising not only the sensor but also the concept of operations, processing, and potential for collaborative and synergistic observations. Highly configurable sensors such as CREWSR enable the utilization of new “cognitive sensing” concepts, where the sensor is aware of the characteristics of the scene to be viewed and can reconfigure itself in real time to adjust where it is looking, the dwell time, the spatial resolution, and depending on the platform, the geometrical vantage point. Observing System Simulation Experiments (OSSEs) have shown forecasting benefits of cognitive sensors in regional simulations, and new laboratory testbeds are now being developed to characterize end-to-end performance in a realistic, test-as-you-fly environment.

References

1. W. Blackwell, Braun, S, Bennartz, R, et al. An overview of the TROPICS NASA Earth Venture Mission. Q J R Meteorol Soc., 144: https://doi.org/10.1002/qj.3290, 2018.

2. W. Blackwell, et al., “High Revisit-Rate Tropical Cyclone Observations From the NASA TROPICS Satellite Constellation Mission,” Proceedings of the IEEE, doi: 10.1109/JPROC.2025.3582502, 2025.

3. A.Gagnon, S. Hasler, J. Chew, W. Blackwell, R. Leslie, M. DiLiberto, K. Cahoy, “An Initial Validation of the NASA TROPICS Pathfinder Microwave Radiometer Observations,” IEEE J. Sel. Top. Appl. Earth Obs., 2025.

4. W. Blackwell, et al., “Advances in designing, building, and testing intelligent, data-driven sensors for high-resolution microwave sounding and imaging from small satellite platforms,” Proc. SPIE 13192, Sensors, Systems, and Next-Generation Satellites XXVIII, 1319203; https://doi.org/10.1117/12.3026773, 2024.