Imagico.de

Geovisualizations

by Christoph Hormann

home page : Geodata products : Green Marble global mosaic version 2.1

The Green Marble mosaic version 2.1

The Green Marble mosaic version 2.1 described on this page has been superseded by the Green Marble version 4.

The Green Marble version 2.1 is a whole earth image mosaic assembled from visual color satellite images. It is successor of the Green Marble version 1, the first truly global mosaics covering the full planet surface from the equator to the poles based on actual measured colors and with seamless coverage of the oceans. And it is the first truly cloud free mosaic with no residual clouds even in critical areas in the tropics. The Green Marble version 2.1 offers a higher quality uniformly across the whole earth surface than any other product currently available. Compared to version 2 it offers an expanded and updated databasis for the water surfaces and as a result higher quality and lower noise levels in their depiction.

The Green Marble represents the surface color at the local vegetation maximum or snow/ice minimum at any part of the planet - hence the name. So in total it does not show any particular point of time but instead shows a generalized typical appearance of the earth surface.

Key properties

Full coverage of the planet surface up to the poles and including the oceans
100 percent cloud free
Based on MODIS surface reflectance data for land areas and sea ice, primarily from 2015-2019, Sentinel-3 water reflectance data for water areas, primarily from 2017-2020
250m/300m resolution on both land and water, processed at 250m resolution
Depiction of the average vegetation maximum and snow/ice minimum appearance at any point on earth
Sea ice rendering showing either the typical summer extent or maximum ice free water.
Available as linear surface reflectance values as well as tone mapped and relief shaded images in any projection. Different shading variants available for the polar regions

Improvements of version 2

Compared to version 1 the version 2 mosaic offers the following improvements:

Updated data basis from mostly 2015-2019.
Globally uniform resolution of 250m/300m even on the open ocean.
New data basis for the water offering higher quality and lower noise levels from very recent Sentinel-3 data.
New processing technique for the polar regions offering higher quality rendering from a shorter time frame of data (2016 to 2019).
Improved color accuracy, in particular for areas with no or little vegetation.
Broadened data basis and improved processing offering lower noise levels in particular also in critical areas of the tropics.
Additional rendering options and variants available:
- Selective HDR tone mapping for better readability of the Antarctic. This is the default tone mapping, the previous globally uniform rendering can be produced on request.
- Morning and afternoon shading available for the Antarctic and high latitude Arctic in addition to the standard shading minimized rendering.
- Ocean rendering either with typical summer sea ice extent or with open water maximum.
- Water only mosaic is also available on request.

Improvements of version 2.1

Compared to version 2 the version 2.1 mosaic offers the following improvements:

Updated and extended data basis for water areas depiction using two additional years of Sentinel-3 data.
Slightly adjusted parameters for sea ice depiction.