Due to restrictions within the current architecture of the global observing system (GOS), space-based remote sensing of Earth suffers from an acute data-deficit over the critical polar-regions. Currently, observation of high-latitude regions is conducted using composite images from spacecraft in geostationary (GEO) and low-Earth orbits (LEOs) . However, the oblique viewing geometry from GEO-based systems to latitudes above around 55 deg  and the insufficient temporal resolution of spacecraft in LEO means there is currently no source of continuous imagery for polar-regions obtained with a data refresh rate of less than 15 minutes, as is typically available elsewhere for meteorological observations.
- elliptical orbit
- low-thrust propulsion
- sun-synchronous orbit
Anderson, P., & Macdonald, M. (2013). Sun-synchronous highly elliptical orbits using low-thrust propulsion. Journal of Guidance, Control and Dynamics, 36(6), 1849-1855. https://doi.org/10.2514/1.59848