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Guo J.,Shandong University of Science and Technology | Guo J.,Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG | Liu X.,Shandong University of Science and Technology | Chen Y.,Shandong University of Science and Technology | And 2 more authors.
Marine Geophysical Research | Year: 2014

Heights as the basic geographical information are very important to study marine geophysics, geodesy and oceanography. Based on the astronomical leveling principle, we put forward a new method to unify the normal height (NH) datum along one ship route across sea with the ship-borne gravimetry and global navigation satellite system (GNSS) techniques. Ship-borne gravimeter can precisely measure gravity anomalies and the GNSS technique is used to measure precise sea surface heights (SSHs) along the ship track across sea. Precisions of ship-borne gravities and SSHs are improved with the colinear adjustment. To remove the effects of sea wave and wind, the Gaussian filter is used to filter residuals both between the ship-borne and modeled gravities from EGM2008 to degree 2160, and the measured and modeled SSHs from DTM10MSS, respectively. Deflections of the vertical (DOVs) along the ship route are estimated from the measured gravities with the least squares collocation method. The astro-geodetic survey is made on continent and island to improve the accuracy of DOVs along the route. We use the new method to connect NHs on the coastal sea of Shandong Peninsula, China. The results indicate that the method is very efficient to precisely connect the NH along the ship route across sea. © 2014 Springer Science+Business Media Dordrecht. Source


Guo J.Y.,Shandong University of Science and Technology | Guo J.Y.,Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG | Guo J.Y.,CAS National Astronomical Observatories | Yang L.,Shandong University of Science and Technology | And 4 more authors.
Science China Earth Sciences | Year: 2012

This paper deals with the backscatter coefficients known as sigma0 at Ku band and C band based on the GDR-M (Merged Geophysical Data Record) of TOPEX/Poseidon (T/P) through Jan. 1993 to Dec. 2004 over land surface of China. After smoothing and interpolating the backscatter coefficients for both bands, we achieve the 5′×5′ grid data and the time series of backscatter coefficients in 12 years. The spatial distribution of sigma0 over typical areas (wetland, desert, mountainous area, agriculture base, etc.) of Chinese territory is analyzed and discussed. The fast Fourier transformation (FFT) is used to detect the cycles of seasonal variations of sigma0 time series and gives that the annual period is the major cycle. Meanwhile a semiannual period is also found in some places. We use the least squares method on both periods and find that the amplitude of annual period is obviously greater than that of semi-annual period. The relationship among the anomalousness of time series, variations of environment and climate change, and the serious natural calamity (flood, drought) is also discussed. Data of topography slope extracted from SRTM are used to do correlation analysis with the backscatter coefficients in parts of China to quantify the impact of slope on backscatter coefficients in Ku and C bands, and the results show that they all have a negative correlation but the magnitudes are different in different places with different coverages. Such as the area of Liaoning and Jilin has the maximum correlation -0. 56, the Taklimakan Desert has the minimum correlation -0. 11, and the other places commonly have correlations in (-0. 3, -0. 5). © 2012 Science China Press and Springer-Verlag Berlin Heidelberg. Source


Kong Q.,Shandong University of Science and Technology | Kong Q.,Chinese Academy of Sciences | Kong Q.,Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG | Guo J.,Shandong University of Science and Technology | And 4 more authors.
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University | Year: 2013

In order to achieve the centimeter-level precise orbit determination for the HY-2 satellite, the methods of orbit determination based on DORIS and SLR are discussed. We have simulated DORIS and SLR observation data for the HY-2 satellite, defined the methods and processes of precise orbit determination. In addition we have discussed the orbit determination accuracy using simulated data given different observation errors, and analyzed the impact of different distribution of ground beacons on orbit determination accuracy and consuming time. In order to obtain more accuracy results, we also analyzed the effect of two observation technique weights on orbit determination accuracy. Experiment results indicate that the optimization of beacon stations can significantly improve the orbit determination precision and save consuming time. Reasonable weights on a variety of technology measurements can make the accuracy of result to achieve the best during the integrated technology orbit determination, if we give DORIS and SLR observations 0.3 mm/s and 10 mm weights respectively, and the obit determination accuracy can achieve centimeter level. Source


Guo J.,Shandong University of Science and Technology | Guo J.,Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG | Mu D.,Shandong University of Science and Technology | Mu D.,Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG | And 4 more authors.
Acta Geophysica | Year: 2014

The Level-2 monthly GRACE gravity field models issued by Center for Space Research (CSR), GeoForschungs Zentrum (GFZ), and Jet Propulsion Laboratory (JPL) are treated as observations used to extract the equivalent water height (EWH) with the robust independent component analysis (RICA). The smoothing radii of 300, 400, and 500 km are tested, respectively, in the Gaussian smoothing kernel function to reduce the observation Gaussianity. Three independent components are obtained by RICA in the spatial domain; the first component matches the geophysical signal, and the other two match the north-south strip and the other noises. The first mode is used to estimate EWHs of CSR, JPL, and GFZ, and compared with the classical empirical decorrelation method (EDM). The EWH STDs for 12 months in 2010 extracted by RICA and EDM show the obvious fluctuation. The results indicate that the sharp EWH changes in some areas have an important global effect, like in Amazon, Mekong, and Zambezi basins. © 2014 Versita Warsaw and Springer-Verlag Wien. Source


Wang J.,Shandong University of Science and Technology | Wang J.,Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG | Guo J.,Shandong University of Science and Technology | Guo J.,Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG | And 2 more authors.
Open Civil Engineering Journal | Year: 2015

In this paper , we proposed a new method to build covariance matrix of gravity anomaly based on the spherical harmonic expansion of gravity anomaly , and then combined with the measured gravity data we can realize the fast and high precision interpolation and extrapolation of gravity anomaly according to the principle of least squares and the remove-compute-restore technique. The feasibility of this method is proved through the simulation experiment. © Wang et al.; Licensee Bentham Open. Source

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