Details

Autor(en) / Beteiligte

• Geiger, Sean
• Pett, Todd
• Ocampo, Carlos
• Davis, Michael S.
• Bennett, Stephen C.

Titel

BOWIE-M: Process to Develop the Next-Generation ESPA-Class Weather Sounding Microwave Radiometer

Ist Teil von

• 2022 IEEE Aerospace Conference (AERO), 2022, p.1-8

Ort / Verlag

IEEE

Erscheinungsjahr

2022

Quelle

IEEE Xplore Digital Library

Beschreibungen/Notizen

• The Ball Operational Weather Instrument Evolution-Microwave (BOWIE-M) is a sounding radiometer designed to provide atmospheric vertical moisture/temperature profiling (AVMP/AVTP) from the surface of the Earth to the mid-to-upper atmosphere. BOWIE-M data enables an environmental data record (EDR) set compatible with those produced by heritage sounder radiometers. Radiometers passively measure electromagnetic energy corresponding to atmospheric moisture density or temperature profiles, using frequencies and bands selected to correspond to specific altitudes or for retrieval of surface parameters. Radiometer data provides the majority of inputs for weather forecasting algorithms, used around the world on an hourly basis. An overview of the design strategy for BOWIE-M is presented here. The advent of the Evolved Expendable Launch Vehicle (EELV) and the associated EELV Secondary Payload Adapter (ESPA) standard, as well as similar SpaceX secondary payload standards (Dispenser Ring 15"/24", Starlink Adapter 15"/24" [1]) provide an opportunity for small spacecraft to be placed in orbit on a low-cost berth. BOWIE-M has specifically been designed to take advantage of these low-cost rideshare opportunities to reduce cost. The BOWIE-M architecture adheres to several key requirements identified early in its development: satisfying operational sounding requirements, use of integrated miniaturized low-power channelization assemblies, integrated miniaturized signal sampling, modular electronics, targeted digital processing capability, a consistent grounding approach to minimize noise, simplified RF front-ends and standardized interfaces, all designed to support affordable ESPA- or SpaceX-compatible secondary payload rideshare compatibility. While achieving the goals above, BOWIE-M's performance was also targeted to meet that requested by the National Oceanographic and Atmospheric Administration (NOAA) [2]. The initial selection of the measured frequency bands, the "channels", reflected heritage NOAA radiometers, and was further refined during a 2020 NOAA-funded study that Ball performed to identify channel change effects on performance. These changes' effects informed the ability to modify the channel properties and thereby the architecture and implementation of the BOWIE-M design. Further enhancements are under study internally at Ball in 2021 to improve upper atmospheric sounding performance beyond the original 2020 NOAA study results. The antenna and feedhorn design followed an evolution over the course of multiple studies, and is dependent upon multiple parameters: ground track goals, mission altitude, ground footprint, cross vs. conical scanning, signal polarization, and measurement of Earth and calibration features. Radiometer signal sampling is another key design parameter, driven in part by integration time for each spatial sample. Heritage integration times were considered, and evaluated against corresponding "overlap" between adjacent samples. This was addressed in the 2020 NOAA study, and further clarification by NOAA about these goals has been forthcoming in 2021.