Cubesat Fourier Transform Spectrometer (CubeSat-FTS) for Three-Dimensional Global Wind Measurements

Global measurements of vertically-resolved atmospheric wind profiles offer the potential for improved weather forecasts, and superior predictions of atmospheric wind patterns. Prior studies have indicated that improved wind measurements offer numerous societal and economic benefits. Vertically-resolved 3-D wind vector data products can provide improved hurricane forecasts (including reduced overwarnings), better off-shore drilling platform evacuation decisions, improved global wind and weather forecasts, aircraft fuel savings (military and commercial), improved routing for shipping, improved military weapons effectiveness, and replacement of radiosonde networks.

A novel small-satellite constellation utilizing Fourier Transform Spectrometer (FTS) instruments onboard 6U CubeSats can provide measurements of global tropospheric wind profiles from space, at very low cost. These small satellites are called FTS CubeSats. The constellation consists of groups of three FTS CubeSats flying in formation and separated by a known time delay. This geometry enables cooperative moisture-field measurements which can be combined to provide vertically-resolved profiles of the wind field on a global basis. A constellation of twelve formation-flying FTS CubeSats would allow measurement of the global wind field on a twice-daily basis.

The FTS CubeSat system also includes innovative algorithms to extract accurate wind vector measurements. The algorithms leverage imagery-based methods (e.g., atmospheric motion vectors) while preserving all the vertical and horizontal information of the remotely sensed moisture field. This method uses hyperspectral radiances directly to estimate the horizontal wind field, while the height of the estimated wind vectors is assigned using the radiance observations along with temperature profiles from spatially and temporally coincident numerical weather prediction fields. This provides wind vectors with more numerous vertical samples, and with fewer spatial discontinuities.

This paper will describe the design of the FTS CubeSat instrument, which is a miniaturized version of the successful Cross-track Infrared Sounder (CrIS) hyperspectral sounding instrument. The FTS CubeSat spacecraft leverages recent advancements in multiple CubeSat technologies, including power systems, attitude determination and control, and communications. System and subsystem trades will be discussed, which optimized the overall system design with emphasis on science mission requirements while balancing overall mission cost. The algorithm approach used to extract the vertically-resolved wind vectors will also be described.