Polar orbiting satellites orbit in a path that closely follows the Earths meridian lines, passing over the north and south poles once each revolution.

As the Earth rotates to the east beneath the satellite, each pass of the satellite monitors a narrow area running from north to south, to the west of the previous pass. These strips are joined together to produce a picture of a larger area.

Polar satellites circle at a much lower altitude than geostationary satellites - at about 850 km. This means that polar satellites can photograph closer up than the high altitude geostationary satellites.

Polar satellites, therefore, provide more detailed information about violent storms and cloud systems.