The DMSP constellation consists of two primary satellites flying at an altitude of 830 kilometers in a near-polar, sun-synchronous, 101-minute orbit. Each spacecraft is three-axis stabilized and oriented toward Earth. The main cloud-imaging sensor collects images across a 3000-kilometer swath, providing worldwide coverage every 12 hours.
Mission sensors aboard the satellites collect several types of data. Visible and infrared day and night imagery are used to analyze cloud patterns. Measurements of microwave radiation emitted from different heights within the atmosphere reveal temperature, water vapor, soil moisture, and rain rate—even over cloud-covered regions. Measurements of electrons and ions at different energy levels are used to forecast the location and intensity of Earth's aurora and predict the performance of radar and long-range ground communications. Space environmental data are also acquired for study.
Each satellite provides continuous encrypted mission data to local military ground-based and shipborne tactical terminals. The data are also stored onboard the satellites for later transmission to strategic ground processing centers.