High density sampling areas (dark green) from commercial satellites include busy maritime regions (for example areas of military exercises and the Grand Banks where there are iceberg hazards) and areas of conflict (notably east Ukraine), and areas of higher population density in the west.
National programmes are also reflected in different densities of sampling noticeable between neighbouring countries, for example Portugal vs. Spain and Brazil vs. its neighbours.
High sampling in the western Arctic reflects demand for imagery to support regular ice charting by the Canadian and US governments, but the density of sampling is in part a reflection of the convergence of satellite orbits.