We use two methodsto get the ocean floor deformation data caused by the 2011 Tohoku-Oki earthquake. Then the gravity effects due to the redistribution of ocean floor mass can be calculated through Fourier transformation and Fourier inverse transformation. These gravity effects are analyzed and compared to the gravity data observed by GRACE satellite. The results show that these gravity effects are notable, and should be of concern during extracting coseismic gravity changes.

Using GRACE gravity field solutions (RL05) released by the CSR, we estimate the global mean ocean mass change by applying several different filtering methods.  To compare, we also use GRACE-based DDK1-DDK5 filtered datasets provided by GFZ to estimate global mean ocean mass change.  The results show that different filtering methods lead to significant differences in estimates of global ocean mass change, including geographic patterns, time evolution and frequency characteristics.  During the period from 2002 to 2014, an increase rate of global mean ocean mass change is 1.17-1.26 mm/a given by CSR RL05 datasets and 1.29-145 mm/a derived from GFZ DDK solution; the acceleration of the two datasets are 0.1 mm/a2 and 0.07 mm/a2 respectively.

The applicability of the recursive algorithms of fully normalized associated Legendre functions (FNALFs) is an important indicator to evaluate their quality.  We discuss four recursive algorithms of FNALFs including the standard forward column algorithm, the standard forward row algorithm, the recursive algorithm between every other order and degree, and the Belikov algorithm.  The applicability of these algorithms are evaluated and compared from three aspects: the first relative numerical accuracy, the second relative numerical accuracy, and the computation speed and efficiency.  We prove that the applicable intervals of standard forward row algorithm are the least.  While θ∈[-1,1], the standard forward column algorithm, the recursive algorithm between every other order and degree, and the Belikov algorithm are applicable for degrees less than 1 900, the first algorithm is the fastest.  Furthermore, the recursive algorithm between every other order and degree, and the Belikov algorithm are applicable for degrees less than 3 000, with the latter being the best.

This paper introduces an new “spherical model” formula of gravity’s middle layer correction algorithm, which considers the influence of earth curvature.  We then, through different calculation examples, analyze error comparisons between the two algorithms.  Results show that the magnitude of the maximum errors can reach 0.4 mGal, so this paper suggests that it is necessary to use the new gravity’s middle layer correction algorithm in surface gravity prospecting work.

In this paper, the determination methods of vertical deflection, including numerical fitting, GNSS leveling, Earth gravity field model, and numerical fitting based on remove-restore technique, are investigated.  The experiment is conducted using a high precision data set of GNSS leveling and  vertical deflection from the project of the geoid slope validation survey of 2011(GSVS2011).  The results show that numerical fitting, Earth gravity field model, and numerical fitting based on remove-restore technique have good fitting accuracy, that the Biharmonic (v4) method from numerical fitting model has better fitting accuracy, and that fitting accuracy can be improved based on the remove-restore technique.  However, the accuracy of the GNSS leveling method is relatively poor.

The latest UTCSR GRACE RL05 monthly gravity field models were processed by using de-correlation and 300 km radius Gaussian smoothing, and the co-seismic and post-seismic deformations of the Sumatra MW8.6 earthquake are extracted successfully for the first time.  Pre-seismic and post-seismic deformation rates around the epicenter are calculated by using least squares. The results show that co-seismic deformation of about -8－14 cm, pre-seismic deformation rates of about 1－4 cm/a and post-seismic deformation rates of about -1－-3 cm/a can be detected by GRACE satellite gravity surveying.

This paper is to acquire the surface deformation caused by an intrusion and small eruption during June 17-19, 2007, along the east rift zone of Kilauea volcano, Hawaii.  The InSAR technique is applied to monitor and analyze the volcano’s deformation, with verification from the synchronized GPS data.  Significant surface deformation is observed around Makaopuhi, where maximum 30 cm displacements in LOS occurred. The acquired deformation shows a good consistency with the GPS observations, and the RMSE between DInSAR and GPS is 1.8 cm in LOS direction.

A modified Kalman filter is designed for the kinematic POD, which combines the advantages of the least square adjustment and the Kalman filter.  Then the GRACE GPS data are processed with the modified Kalman filter, and by comparison with the GFZ’s reduced-dynamic POD, the accuracy on x, y and z directions are better than 3 cm, 4 cm, and 3.5 cm respectively. According to the performance of the new Kalman filter, we can expect that it can be used in the kinematic orbit determination for space borne GPS data with 1 Hz sampling rate in the future.

Due to a lack of an external reference during days the navigation constellation runs autonomously without ground support,the results of autonomous orbit determination cannot be effectively assessed. In order to resolve this problem, this paper presents the assessment of the results of autonomous orbit determination based on Bayesian theory. The method adequately takes the prior information of orbit-determination error into consideration and uses it to provide position reference. To solve the problem that on autonomous orbit determination issues there are no direct observations of the orbit-determination error, we advise using the trace of the covariance matrix of the Kalman filter as observation information for orbit-determination error. To prove the method, a simulation of the autonomous orbit determination progress is conducted.The results of the simulation show that, for a single satellite, the error of the estimated is controlled within 0.5m, in 24 days. The feasibility of the method is confirmed by the result. Using this method can provide support for autonomous integrity monitoring of on-board autonomous operation software.

In this paper,an epoch-difference GNSS clock densification algorithm is tested.The high precision relative satellite clock bias is obtained by epoch-difference carrier phase observation.By using relative clock results,the high-rate 30 s satellite clock products are then densified from IGS 5 min interval precise satellite clock products.The results show that compared with mathematical interpolation methods,the epoch-difference clock densification algorithm has better performance.The densification precision using the epoch differential model is below 0.03 ns.Furthermore, the differential among different types of satellite clock is small.

For quantitatively researching the performance improvements of different levels of the GNSS multi-constellation integrated navigation system, this paper constructs the corresponding quantitative indicators to analyze the performance improvements of the system quantitatively.  Through a simulation experiment, it verifies the validity of indexes, and analyzes the rule of the performance improvements of the system, along with combination levels and cut-off elevation angle changes, and proposes the optimal system combination at all levels.  The paper demonstrates that the high-level of the multi-constellation system not only improves the flaws of single and low-level configurations, but it also largely enhances the performance of constellation.

To reduce hardware costs, mixed single and dual frequency GNSS mode is used in deformation monitoring.  The key technological challenge of this mode concerns how to use the data of dual frequency points to build a precise regional ionosphere error correction model for the single frequency point, so that the accuracy of single frequency points can meet the demand.  To meet this challenge, the data of land subsidence monitoring network in Nansha, Guangzhou is used to analyze 4 different ionosphere correction models (LCM, DIM, LIM and LSM) and processing strategies.  The result shows that all of the 4 models can improve the monitoring precision of single frequency point, and that LCM and LIM perform better than DIM and LSM.  It also indicates the strategy using three dual frequency points nearest to the single frequency point is best for constructing the ionosphere correction model.

During the period of November and December in 2013, for the coefficient larger than 0.535 and sig value less than 0.01, it is concluded that there are significant positive correlation properties between GPS PWV and PM2.5.  The coefficient between PM2.5 and the reconstructed PWV sequence amounts to 0.749, in which the reconstructed PWV sequence eliminates high frequency noise, small disturbances and small scale system influences.  It better reflects the positive correlation between PWV and PM2.5 that the coefficient of the reconstructed high frequency between PWV and PM2.5 amounts to 0.839.

In this paper, the conversion factor K of 2009 to 2013 data from 9 radiosonde stations in Xinjiang region is calculated using integral method as a reference value.  Through the analysis of K of the Emardson model in the same latitude and different elevation radiosonde stations, we analyze the applicability of elevation.  We rationally choose five radiosonde stations, and using different numbers of samples to predict the remaining four radiosonde stations’ K value of 2014, verify the adaptability in planar space and time of the Emardson model.  Our research shows that: 1) the Emardson model calculated K with elevation change is relatively stable in Xinjiang; 2) in temporal distribution, increasing the number of samples can improve the accuracy of the Emardson model to a certain extent.

A weighted total least squares (WTLS) cost function is obtained by considering the first-order error propagation of the design matrix elements in conic fitting problems with heteroscedastic measurements.  The cost function is justified as the Rayleigh quotient form, which means the parameters to be estimated are the eigenvector associated with the smallest eigenvalue of a given positive-defined matrix. Our algorithm is an iterative singular value decomposition, and a simulated data experiment is also presented to verify the algorithm.  The results show that this method is more stable, demands less calculation, and is relatively simple and efficient．

The standardized residuals of polluted semi-parametric models have been influenced by model system structures when making use of the method of quasi-accurate detection of gross errors, so it is difficult to choose the quasi-observations in the primary selection in this way.  In this paper, the observations are selected with the modulus maxima under the wavelet transform filter analysis as primary quasi-observations.  Then the location and value of gross errors are realized on condition of the minimum of the real errors related to quasi-accurate observations.  At last, penalized least square estimation is used to separate the systematic errors to obtain parameter estimation accurately.

We analyze the Ms6.0 earthquake in Jinghe on November 1, 2011 and the Ms 6.6 earthquake on the border of Xinyuan and Hejing on June 30, 2012.  We identify earthquakes with magnitude greater than ML3.0 since Jan 2009, in a range of 100 km around these two earthquakes.  We use CAP method and first motion direction about P-wave inverse the focal mechanism solution, then do a cluster analysis for these focal mechanism solutions.  Our study shows that, about six months before the main-shock, the earthquakes’ fault nature changes from disorder to order; the maximum compressive principal stress P-axis azimuth changes from random to prominent, which is consistent with the direction of main-shock’s step by step.

Firstly,the mathematical model of one-dimensional wave equation is built, then staggered grid finite difference forward modeling is introduced, and finally the staggered grid difference forward and genetic algorithms are combined to achieve the inversion of wave equation. We apply the genetic algorithm inversion of wave equation to study the numerical synthesis of single-channel simulated recording, then analyze the impact of various parameters on the inversion results. Finally,we examine engineering examples to verify the effects of the wave equation prediction genetic algorithm inversion, including both forward and backward comparison prediction the same velocity value times segment mileage. S-wave inversion has better consistency, due to the S-wave energy and its ability to tolerate interference in the same mileage acquired segments close to the S-wave.

Using correlation and regression analysis methods, this paper studies the relation between Wushi strain and air temperature, air pressure and water level. The results show that the air temperature is the main factor affecting the body strain year period in Wushi-the borehole body strain’s phase hysteresis temperatures is about 322 days. The influence of air pressure strain year frequency is weaker on Wushi borehole body strain, but affectsthe main factors of diurnal variation. Further we explore the possible mechanism of the influence of air temperature and air pressure on borehole body strain.

According to the requirement of Web service in the network data acquisition system of gPhone gravimeter, we design and realize an embedded Web service system.The design and realization of the system is based on uClinux platform and lightweight BOA Web server. We realize the remote data download, meter monitoring and control functions using common gateway interface(CGI) program written in C language.

The system of quasi-real time broadcast in earthquake scene uploads the seismic process, damage circumstances, disaster relief and recovery, etc to the system server for examine, verify and issue. The system has the characteristics of quasi-real time, dynamic continuous process, open and concurrent response. Users can query and watch the quasi-real time video data through the Internet.

The earthquake monitoring principles of the second and third generation nuclear power plants in China are introduced in this paper.  By calculating the domestic seismicity data, the characteristics of earthquakes that may influence the safe operation of third generation nuclear power plant are analyzed, and then the manner of earthquake alarms for the third generation nuclear power plant is compared with those of the second generation in our country.  The result is that the false and missing alarms would be less clear with the OBE warning method for the third generation nuclear power plant than for the second.  Thus, the earthquake monitoring method for the third generation nuclear power plant is more moderate.