TerraColor® Landsat Data Specifications
The source Landsat 7 (ETM+) satellite imagery used to create TerraColor was produced for the Earth Science Enterprise Scientific Data Purchase Program initiated by NASA (the US National Aeronautics and Space Administration). The following are published specifications on this dataset, and also specifications that apply to TerraColor:
- Year of data acquisition - Primarily year 2000, with some scenes from 1999, 2001 to 2003.
- Registration accuracy - All Landsat scenes used as input to the mosaic products were rigorously orthorectified using the best geodetic control and elevation data available to the US government. The products have been verified to have absolute positional accuracies of +/- 50 meters RMSE, with RMSEs under 25 meters validated in some parts of the world.
- Cloud cover - 90% of the source Landsat scenes used have less than 10% cloud cover. Cloud cover is heaviest over equatorial tropical rain forest areas, while temperate regions can be up to 99% cloud free in some areas.
- Data quality - Overall data quality is excellent, but occasional errors inherent to the Landsat sensor (scan line errors, etc.) can be found in some areas. The imagery is virtually seamless for the most part due to use of sophisticated contrast adjustment and edge feathering algorithms, and use of scenes from the growing season where possible.
In addition, TerraColor has been further processed by Earthstar Geographics to improve upon the NASA source data in many areas. See our current TerraColor Upgrades PDF for examples of upgrades we have made recently. Improvements include integration of less cloudy or cloud-free imagery in many places, correction of gaps and mis-registered tiles, seamline removal, and scan line error corrections. Most corrections were made using imagery from alternate precision terrain corrected Landsat 7 scenes. Future enhancements will be made as part of our upgrade program.