Advances in the vision systems in orbiting satellites are revealing ancient pyramids in the desert sands of Egypt, the ruins of hidden temples and cities in the jungles of South America, Cambodia and other areas and even man-made structures under water in oceans and lakes.
Satellites with imaging systems that can see through clouds and forest to reveal differences in the vegetation below. Operating around 400 miles above Earth’s surface, these systems can provide a virtual road map of the buried structures. For example, as the abandoned buildings with limestone and lime plasters, like the Mayans used disintegrate, chemicals from the stones seep into the soil. This prevents some plants from growing around the structures and affects the chemistry of those plants that do grow.
The improvements from two commercial Earth-observation satellites, the Landsat and the IKONOS, demonstrate the detection differences of two different systems.
With its initial launch in 1972 and subsequent launches as recently as 2013, Landsat has the world’s longest continuously acquired collection of space-based moderate-resolution land remote sensing data.
Launched in Sept 1999, the IKONOS satellite sensor is a high-resolution satellite with capabilities that include capturing a 3.2m multispectral, Near-Infrared (NIR) 0.82m panchromatic resolution at nadir (its lowest point). It was decommissioned Jan 22, 2015 but previously generated images are still being analyzed.
Unlike the Landsat imaging system that has a nominal resolution of 30 meters, the IKONOS system can capture a nominal resolution as close as 1 meter. At this scale, individual pyramids, pathways and small structures become apparent.