Nebula Public Library

Thousands of man-made objects are currently in orbit around the Earth. These range from active satellites to flecks of paint, via spent rocket stages and fragments of satellite debris. Due to the drag of the very thin high altitude atmosphere, these objects have slowly decaying orbits, and will eventually re-enter the Earth's thicker, lower atmosphere. Most will be destroyed on entry due to the aerothermal heating experienced at hypersonic velocities at altitudes between 40 and 80km. However, some objects reach the ground.

Ocean Surface Current is one of the most important ocean properties for oceanographers and operators in the maritime domain. Improved monitoring of ocean currents is systematically the number one requirement that emerges from any science or end user requirement surveys. Wavemill is a novel hybrid interferometric SAR system first proposed by ESA/ESTEC [Buck, 2005]. It offers the possibility of generating two-dimensional wide swath, high resolution, high precision maps of surface current vectors and ocean topography [Buck et al., 2009].

In recent years the need for accessing historical Earth Observation data information has greatly increased, driven by long term scientific and environmental monitoring. The need to preserve such data indefinitely has led to the establishment of the Long-Term Data Preservation (LTDP) guidelines for Earth Observation. However to make full use of this data, it is necessary to have sufficient quality information available to be assured about the data quality.