Overview of the northern Great Barrier Reef, Australia
TerraColor Global Satellite Imagery
Our TerraColor imagery was designed from day one to meet the needs of a wide variety of users. From magazines who just need an image of an island to organizations hosting global online map services, our imagery has been used extensively in all corners of the globe for over 10 years. A few examples of various applications are shown in the lower part of this page.
The original TerraColor Global product was built using our simulated natural color process from Landsat 7 satellite imagery from the 1999-2002 time frame (based on the GLS2000 Landsat set). This is a high quality base set of images, but does not cover the polar areas. (Most of the global imagery products offered by competitors are also based on GLS2000.) In response to client requests, we made the following improvements to our original product:
- Since individual images of many areas can be compromised by clouds or poor image quality, we greatly improved the base GLS2000 dataset by incorporating better imagery and newer imagery. To date we have upgraded or added imagery covering over two million square miles to reduce cloud cover and improve quality, using Landsat 8 imagery since 2013.
- In addition, we added imagery to fill in all the gaps and holes in the GLS2000 coverage (such as Antarctica and the remote Arctic Ocean islands), so we now provide imagery of the entire earth's surface (even the poles). So TerraColor can be easily used in 3-D virtual globe applications or any application requiring complete global coverage.
- Simulated natural color imagery can have weaknesses, one being limited portrayal of water color and depth. (This is most apparent in tropical shallow water areas such as the Bahamas or Great Barrier Reef.) To improve the quality, we replaced about 25% of the original with true color imagery. So most coral reefs, shallow waters and coastal features are shown properly.
- Because users wanted a "clean" product that required no editing or clean-up in the oceans, we developed a detailed, proprietary land/ocean mask. TerraColor was then processed through the mask to remove distracting clouds, ice and Landsat image edges from ocean areas. (This is one of several reasons why many leading web mapping services use TerraColor Global.)
- Also, users asked us to fill the ocean areas with a uniform blue color, and later with a bathymetric shaded relief image (a la Google) to add interest to the oceans. We now offer two bathymetric shaded relief image color options.
- Users also asked for better ways to visualize the polar areas. (Standard global projections can introduce huge distortions in the size and shape of polar areas.) So we now offer versions of the TerraColor Global imagery for the Arctic Ocean and Antarctica in map projections optimized for visualizing polar areas.