SLR Analysis

The NSGF numerically models satellite orbits accurately in software to predict trajectories and determine Earth Orientation Parameters and Station o-ordinates. To do this every force incident on a satellite has to be understood and delled in software. These include: Gravity from the Earth, Sun, Moon and other Planets in the Solar System Atmospheric Drag Solar radiation pressure Earth Radiation pressure Thermal forcing Tide effects General Relativistic forces Furthermore site information has to be known and accounted for, including: Ocean loading Earth Tides Earthquakes System changes
Below is a plot of the NSGF weekly coordinates in North, East and UP directions since 199
Monitoring the NSGF site is important to understand certain features of the coordinate series. For example there is potentially a relationship between the observed height of the site and the measured water table height after a delay. Go to Water Table Analysis page
As a ILRS Analysis Centre, the NSGF uses Lageos 1&2 and Etalon 1&2 laser data from the NSGF and the global SLR network, to produce a weekly solution of site coordinates and Earth Orientation Parameters. This solution is combined with 5 other analysis centres to form an ILRS product to contribute to the International Terrestrial Reference Frame.