Polar motion refers to the earth rotation axis and surface intersection point’s slow moving on the earth surface [1], realtime acquisition of polar motion is of great signifi cance to high precision satellite navigation, satellite laser ranging and deep space exploration. At present, the international high accuracy polar motion value is obtained through VLBI and SLR technology observation data calculation…

For all the three pillars of space geodesy (the geometry of the Earth surface and its displacements, the orientation of the Earth axis and its rotation speed, and the Earth’s gravity field and its time variations), well-defined, highly accurate and stable global Earth-fixed and celestial reference frames are of primary importance. Over the last decade considerable changes took

Space Very Long Baseline Interferometry (SVLBI) is an extension of the ground-based VLBI technology to space, which involves a simultaneous observation of the same radio source by two stations; one on the ground, the other being space-based. It could not only overcome the baseline length limitation problem specific to groundbased VLBI technology, with a great improvement on the observation resolution, but could also directly…

The high pile wharf has the advantage of slight wave reflection, steady anchoring condition, little investment and the construction time being short. Therefore it has been widely used in coastal areas where the ground has soft soil. But, on the other hand its penetrant structure raises some problems also for the structure. In order to guarantee the request of ships draft, the front water area of the wharf has to be dug more deep,…

Very Long Baseline Interferometry (VLBI) is the unique space
geodetic technique which can provide the Celestial Reference Frame (CRF), the Terrestrial Reference Frame (TRF) and the relationship between the two frames — Earth Orientation Parameters (EOP) at the same time. VLBI has a widely usage in space geodetic, ground
geodetic, geophysical fields and so on. Presently, it can determine the position of the radio source outside the galaxy with 1mas precision, and determine several kilometers length of baseline on the earth’s surface with 1cm precision. Due to its high stability and high precision character, the Celestial Reference Frame outside the galaxy based on VLBI has been the best realization of the quasi-inertial referenceframe since 1980s. VLBI stations are the most important benchmarks in the International Terrestrial Reference Frame (ITRF), and VLBI is one main supporting technique which determines EOP. Till now, space and ground VLBI have accumulated more than 20 years’ data. They provide continuous and long-term data guarantee for space geodetic, ground
geodetic and geographical research.