GEMS microwave radiometer satellites
Weather Stream's small satellites carrying passive microwave radiometers that map 3D temperature and humidity across a swath nearly 2,000 km wide.
Why it matters
Microwave sounding sees through clouds and darkness and improves weather forecasts. Weather Stream says its constellation can match current government weather satellites at a fraction of the cost, which could mean more frequent data.
How the technology works
A passive microwave radiometer measures natural microwave energy coming from the atmosphere, which passes through clouds, and turns it into 3D temperature and humidity profiles. The first pathfinder flew via the ISS in 2019, and the company announced the GEMS2-Amethyst mission's launch in March 2026.
Sources
Updated Oct 22, 2026 · How we source facts · Suggest a correction