Proceedings Article | 20 October 2023
KEYWORDS: Atmospheric sensing, Radiometry, Satellites, Reflection, Temporal resolution, Radar, Prototyping, Ice, Absorption, Troposphere
Two new systems are described to improve present capabilities for high-resolution atmospheric sensing from small satellite platforms. The NASA Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission will significantly improve temporal resolution, and the NASA Configurable Reflectarray for Electronic Wideband Scanning Radiometry (CREWSR) instrument prototype will lead to significantly improved spatial resolution. TROPICS will 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. TROPICS will provide rapid-refresh microwave measurements (median refresh rate of approximately 60 minutes for the baseline mission) over the tropics that can be used to observe the thermodynamics of the troposphere and precipitation structure for storm systems at the mesoscale and synoptic scale over the entire storm lifecycle. The TROPICS constellation mission comprises four 3U CubeSats (5.4 kg each) in two low-Earth orbital planes. Each CubeSat will host a high-performance radiometer 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. The four NASA TROPICS CubeSat constellation satellites were successfully launched into orbit on May 7 and May 25, 2023. The separate TROPICS Pathfinder mission launched on June 30, 2021, in advance of the TROPICS constellation mission, as a technology demonstration and risk reduction effort. CREWSR is a high-resolution, lightweight, low-power multiband (23, 31, and 50-58 GHz) radiometer with a deployable scanning reflectarray. It is envisioned to be fielded on an ESPA-class small satellite platform, whose stowed volume fits within 0.61m x 0.71m x 0.97m envelope. Once in orbit, the platform will deploy a large Reconfigurable Reflective Surface (RRS), as well as a multi-feed antenna connected to a multiband radiometer. These components allow for an electronically scanned beam for radiometric Earth observation. CREWSR would operate with a single, linear polarization, but fully polarimetric operation is also possible in principle. The reflectarray is also compatible with radar use, thus enabling wide-swath radar from a small satellite. This presentation will describe the on-orbit results over approximately two years for the successful TROPICS Pathfinder precursor mission and first light results from the TROPICS constellation mission and will overview the CREWSR design, prototype objectives, and recent laboratory measurement results.
