Astronaut Photography of the Earth
Most the images that comprise the Oceandots Atlas are derived from NASA's online Astronaut Photography
of the Earth database — a growing collection of over half a million images which are made available to the
public by the Earth Observations lab at the NASA Johnson Space Center as part of NASAs
Human Exploration and
Development of Space Enterprise. The images taken by astronauts are used by researchers (and interested members
of the public) as both primary data on the state of the Earth and as secondary data to be combined with images
from other satellites in orbit.
The Oceandots Atlas makes extensive use of these images, specifically what the Astronaut Photography of the Earth database terms 'low-resolution browse images'. Large size versions and high-resolution versions of these images are also used in the Atlas where image detail/quality is high enough.
MODIS Images
Many
images in the Atlas (particularly 'panoramic' style images) are derived from the
MODIS Rapid Response System gallery at NASA
Goddard Space Flight Centre.
MODIS (Moderate Resolution Imaging Spectroradiometer) is a key instrument amongst a suite of remote-sensing devices carried on the Terra (EOS AM) and Aqua (EOS PM) satellites. Terra and Aqua form part of NASA's Earth Observing System (EOS). It is composed of a series of satellites, a science component, and a data system supporting a coordinated series of polar-orbiting and low inclination satellites for long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans. The whole system allows the Earth and its biosphere to be observed and studied as an integrated system with the aim of understanding the global dynamics and processes occurring on the land, in the oceans, and in the lower atmosphere.
Terra's orbit around the Earth is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon, viewing the entire Earth's surface every 1 to 2 days.