Sydney, Australia, 26 June 2006 – GeoSage announced the availability of true-colour, medium-resolution global satellite imagery, offering a very low cost solution to a wide range of visualisation-related applications.
This dataset is based on NASA’s orthorectified Landsat ETM+ GeoCover 2000, which consists of 880+ mosaic tiles covering the entire earth land surface except Antarctica. Each mosaic in a compressed form contains three pan-sharpened, false-colour bands at a spatial resolution of 14.25 m: Band 7 (mid-infrared), Band 4 (near-infrared), and Band 2 (visible green).
Original mosaics are successfully converted into natural- or true-colour composites at a re-sampled resolution of 28.5 m, after applying GeoSage’s spectral analysis techniques and leveraging between spatial details and the total file size of images. True-colour outputs still retain the specifications of GeoCover 2000, such as minimised cloud covers and high positional accuracy.
Since a robust spectral transformation and colour balancing scheme is developed and applied across all individual mosaics, the result is a consistent and visually-appealing representation of global land surfaces circa 2000. This dataset can offer numerous applications. For system integrators, it can be readily combined with other highly popular global data layers such as VMAP and SRTM elevation, to build a global data warehouse or virtual exploration platform, similar to those from major web portals.