Polar weather satellites take around 90 minutes to complete one orbit, and as the earth rotates beneath them, each pass covers a section of earth that is further west. This provides nearly global high resolution coverage without the large parallax displacement errors over higher latitudes that is characteristic of geostationary satellites.
In northern latitudes, polar satellite data is a critical complement to geostationary data with better resolution and minimal parallax error, especially near the center of the swath. However, as the examples above illustrate, regardless of satellite type, viewing angle and parallax displacement should always be taken into account when the exact location of a cloud feature is important.
By Carl Dierking