The Satellite Imagemap is available with seafloor depth portrayed in the ocean areas with a pixel size up to 4km. Oceans and lakes are coloured-by-depth and hill-shaded to show the tectonic structure of the sea bed, revealing continental shelves, mid-ocean ridges and seamounts.
We spent almost a year taking the clouds out, but we can put them back if required! Our global cloud layer shows frontal systems, tropical thunderheads and storms with a pixel size up to 1km based on NASA's polar-orbiting Terra satellite.
Using a camera system sensitive enough to take pictures of clouds by moonlight, military weather satellites provide a view of the Earth's surface at night. Light sources such as streetlamps in urban areas, gas flares in oilfields, bushfires and even the lights of fishing vessels can be identified. Worldwide night-time imagery is available up to 1km resolution, supplied either as an 8-bit greyscale mask, or combined with a darkened Satellite Imagemap as a 24-bit full colour image.
Political map data is available either as an 8-bit country mask, or as a border overlay layer. Our country mask shows the major territories of the world with 254 unique values (brightness levels), allowing easy selection or highlighting of a country's territory. A secondary mask shows internal regions for selected countries. Our political overlay layer shows coastlines, international borders and some internal political boundaries, rasterised from digital map vectors. We can supply the individual data layers or combine them to produce finished maps in a range of styles.
Derived from a number of digital map sources, including Digital Chart of the World (DCW) and World Vector Shoreline (WVS), this 8-bit data layer provides a means of distinguishing land and water surfaces, with the option of showing rivers, lakes and icecaps. As well as the preparation of simple base maps, this layer allows different colour schemes or reflectance functions to be applied over land and water.
