To solve the problem of common mode error(CME) in regional GNSS coordinate time series, the PCA and ICEEMDAN methods are proposed to eliminate the spatial domain error, taking the GNSS coordinate time series in north China as an example.Firstly, we use the PCA filter to extract the CME. Then we use the ICEEMDAN method to decompose the CME to extract the useful IMF components, which reduces the loss of original information. Finally, we compare and analyze the regional filtering results of PCA, ICA and IC-PCA. The results show that the filtering effect of IC-PCA is better than ICA and PCA. The residual RMS in N, E and U directions before and after IC-PCA filtering decreases by 1.93%,1.92% and 7.60% on average, and the filtering results are more consistent with the change trend of the original time series, which effectively reduces the loss caused by PCA on the original time series.

We solve the problem that  the analysis of crustal deformation is affected by outliers in GNSS coordinate time series. Firstly, we introduce the classical data detection method DIA(detection, identification, adaptation) into the GNSS coordinate time series analysis. Then, we use an efficient DIA algorithm for outlier detection. Finally, we use the simulated data and the real data of the Crustal Movement Observation Network of China(CMONOC) to compare the DIA algorithm with the traditional 3σ method. The results show that the DIA algorithm can effectively detect the anomalous values in the GNSS coordinate time series with higher accuracy than the traditional 3σ method. Compared with the traditional DIA algorithm, the computational efficiency of the improved DIA algorithm is significantly improved.

To quantitatively evaluate the time series noise of GPS station coordinates that may be caused by load effects, we propose a temporal noise modeling method to describe the temporal correlation and heteroscedastic properties of noise. The results show that the proposed noise model is superior to FN+WN and AR noise models and can effectively quantify the heteroscedastic characteristics of white noise and quantitatively describe the variation trend of noise content before and after load correction.

The original pseudo-range observations of smartphones are affected by their chips and antennas, so the measurement of pseudo-range observations has large noise and is seriously affected by multiple paths, resulting in inaccurate positioning and uneven trajectory. Therefore, we propose an adaptive switching filtering algorithm for inter-satellite carrier phase smoothing pseudo-range, inter-satellite Doppler smoothing pseudo-range and inter-satellite velocity constraint. It gives full play to the role of phase and Doppler observations, improves the accuracy of pseudo-range observations and smoothes pseudo-range noise. The experiment compares the positioning performance of smartphones in different environments such as single-frequency and dual-frequency, static and dynamic. The analysis results show that the effect of dual-frequency positioning is better than that of single-frequency positioning, and the adaptive switching filter positioning algorithm with inter-satellite difference speed constraint is best. The comparison of the tolerance pseudo-range shows that the accuracy of Xiaomi 8 in the plane direction and the elevation direction is increased by 1.49 m and 1.38 m respectively in the static environment, and that of Huawei P40 is increased by 2.11 m and 1.53 m respectively. In the dynamic environment, the accuracy of Xiaomi 8 in the plane and elevation direction is increased by 1.75 m and 1.25 m, and Huawei P40 is increased by 2.58 m and 1.85 m.

In order to solve the problem that the carrier-to-noise ratio(CNR) data of existing cycle slip detection methods is not effectively utilized, based on influence analysis of the type of BDS on the MW combination observation value, we propose a CNR-weighted MW combination cycle slip-detection model based on the traditional TurboEdit algorithm for different types of BDS satellites. The test results show that the method is superior to the traditional TurboEdit algorithm in effectively reducing the cycle slip miss-detection and false-detection caused by system bias for IGSO and MEO satellites of BDS-2.

We calculate the inter-frequency clock bias(IFCB) of BDS-2 and BDS-3 GEO satellites, and analyze the variation characteristics. The results show that the corresponding phase and pseudo-range IFCB of BDS-2 GEO satellite have obvious time variability and periodicity, while the corresponding phase and pseudo-range IFCB of BDS-3 GEO satellite have no obvious time variability. We analyze the periodic variation characteristics of BDS-2 single-day IFCB, and construct the IFCB modeling function using the period obtained from the analysis. We use the polynomial and mixing harmonic function to model IFCB respectively, and the modeling results are as follows: the average RMS of the mixing function model corresponding to the 4th order harmonic function is 0.003 6 m in phase IFCB fitting, and the corresponding RMS of pseudo-range IFCB is 0.131 3 m. The average RMS of the mixing function model corresponding to the 8th order harmonic function is 0.003 4 m, and the corresponding RMS of pseudo-range IFCB is 0.123 8 m. When using polynomials to model IFCB, the accuracy is improved with the increase of polynomial order, but it is still inferior to the mixing function based on harmonic function. When constants are used to replace BDS-3 phase IFCB results, the average fitting RMS is 0.000 5 m. When pseudo-ranges are used to replace IFCB results, the average fitting RMS is 0.035 2 m.

Since the quality of the solution of the Tikhonov regularization(TR) method is too dependent on the determination of the regularization parameters and less stable when solving ill-conditioned problems in the field of geodesy by TR method, an improved iterated Tikhonov regularization (ITR), combined with generalized cross-validation(GCV), can effectively overcome the above shortcomings.The calculation example results show that the ITR-GCV method is better in terms of solution accuracy, stability, and anti-interference.

Considering the existing global model T_m can not obtain the global regional real-time high-precision T_m, we use the ERA5 reanalysis data provided by ECMWF from 2014 to 2017 to analyze the temporal-spatial variation characteristics of T_m lapse rate on a global scale. The results show that T_m lapse rate has obvious annual cycle and semiannual cycle variation, but its daily variation is slight and has obvious differences on land, sea and different terrains. The T_m lapse rate obviously varies by area and has no significant correlation with longitude, while it has a strong correlation with latitude. Its absolute values decrease from the equator to the poles gradually.

From the observation data of 96 sounding stations in China, we use 1 887 313 sets of data from 2016 to 2018 as the training set, and 635 337 sets of data in 2019 as the test set. We conduct the comparison test with the exponential, ITU-R exponential, dual-exponential and Hopfield models. The results show that the BP model, which takes the surface meteorological information and the spatial location of the fixed point as input features, achieves the best effect by fully taking into account the various possible influencing factors of the refractivity. Compared with the exponential, ITU-R exponential, double exponential and Hopfield models, the RMSE of the best BP model is decreased by 69.8%, 33.1%, 31.9% and 16.8%, respectively. The BP model not only outperforms the traditional models in overall accuracy, but also has a more uniform distribution of errors in geospatial and longitudinal profiles.

We study the data processing of Cryosat-2 SAR mode altimetry data in Arctic ocean. We use a decision tree algorithm to determine the parameters and thresholds for the detection of the open lead observations, and then establish a mean sea level model in the ice-covered region of Arctic ocean named UST-CS2. The results show that UST-CS2 has best consistency with DTU21 model, while the validation results of ICESat-2 laser altimetry data show a standard deviation of 10.72 cm, which is close to the results of DTU21. These results indicate that the UST-CS2 is reliable.

Application of spaceborne reflectance measurements of remote sensing data from the cyclone global navigation satellite system(CYGNSS) and soil moisture active passive(SMAP) soil moisture products, two methods for surface soil moisture retrieval from spaceborne global navigation satellites system reflectometry (GNSS-R) are compared and evaluated. The results show that, the simple linear regression modeling between calibrated gridded effective reflectivity and reference SMAP soil moisture on each aggregated grid pixel is superior to the integrated modeling over global. An inversion model with significant time-domain stability can be produced with 1 a of the training data. On a five-month testing dataset, the RMSE of the estimated soil moisture from the pixel-by-pixel retrieval model can reach 0.056 cm³/cm³, and the correlation between estimated soil moisture and reference soil moisture is 0.9.

To solve the problems of complicated calculation and limited breakdown points of traditional localization methods in point cloud registration, we propose a fast and robust spherical target positioning method. Firstly,combines the weighted Hyper method and least trimmed squares, introduces truncation parameters. Then, obtains a subset by sampling, and minimizes the sum of squared faithful distances of point clouds in the subset to finally obtain fast and robust estimated spherical parameters. The results show that the proposed algorithm can obtain accurate spherical center coordinates. Compared with the robust total least squares and M-estimator, the proposed algorithm significantly improves the breakdown point and the calculation efficiency.

In view of the calculation accuracy and stability of the fully normalized associated Legendre functions(fnALFs) and the applicability of the commonly column-wise recurrence formulas, four types of column-wise recurrence formulas are given based on the principle formula of Legendre function. The research shows that the universality of the indirect algorithm of Belikov’s column-wise recurrence formulais only about 3 100 orders, while the universality of fully normalized direct algorithm is about 15 000 orders. The formula given by Belikov is the best among all the column-wise recurrence formulas. The smaller the coefficient in the column-wise recurrence formulas, the slower the overflow phenomenon appears, the higher the recurrence order, the better the recursive formula.

We calculate the radial receiver functions of each station using the dense broadband seismic array data across the Xiangfan-Guangji fault and measure the crustal anisotropy based on Pms converted phases. The crustal thickness and the average V_P/V_S values are estimated by a new H-κ-c method. The average delay time of the entire survey is 0.275 s and the anisotropy is larger in the Yangtze block (the mean value is 0.344 s) than in the Dabie orogenic belt (the mean value is 0.226 s). The crustal anisotropy intensity of the Dabie orogenic belt varies greatly, with a maximum value of 0.46 s and a minimum value of 0.06 s, and the fast polarization directions (FPDs) are scattered. In the Yangtze block, the FPDs and anisotropy intensity are concentrated, indicating a stable crustal structure. The average FPDs in this area is NW-SE, which has an angle with the strike of the fault and the GPS direction. We suppose the FPDs may be related to the northward subduction of the Yangtze block. The H-κ-c stacking results show that the Dabie orogenic belt has a thicker crust (the mean value is 33.2 km) and a lower VP/VS value (the mean value is 1.74), indicating that the crust is dominated by felsic and intermediate rock compositions, which may be related to the delamination of the lower crust. The Yangtze block has a thinner crust (the mean value is 32.6 km) and a higher VP/VS value (the mean value is 1.78), indicating that it is a stable continental core, and still retains the iron-magnesium composition in the lower crust.

We select the waveform data of 127 M_L≥3.0 earthquakes recorded by 36 stations of Chongqing digital seismic network from 2010 to 2020. Using the joint inversion method of Lg-wave attenuation parameters and station site response, we obtain the attenuation relationship between the three directions of Lg-wave (UD, EW, NS) at the frequency of l to 7 Hz, which is QUD（f）=173.6f^0.77，QEW（f）=154.9f^0.78, QNS（f）=157.6f^0.73. The study area is a tectonic active area with low Q₀ value and high frequency dependence. We calculate the site responses of 36 seismic stations. The results show that the amplitude curve of most stations is relatively smooth, and the site responses of each station are different. Among them, the site response curves of SHG, PAL and JIP stations have abnormal amplification in some frequency band. We select the seismic observation reports of 642 M_L≥2.0 to correct the site response of stations with amplification effect. The average magnitude of most stations is closer to the average magnitude of the network, the correction effect of CQT, SHG and HCB stations is obvious, and the influence of medium attenuation of some stations on seismic wave amplitude is greater than that of site response.

We calculate the GNSS velocity field of Maduo and its surrounding areas in Qinghai during 1999-2016 and 2017-2020, and using continuous slip regression method obtain the surface expansion, principal strain and maximum shear strain rates in this area before the Maduo earthquake. We analyze their dynamic evolution characteristics. The results show that: 1)There is no obvious adjustment of tectonic movement in this area before the earthquake; 2)Before the earthquake, the surface expansion rate near the epicenter decreased, indicating that the accumulation of strain energy near the epicenter decreased; 3)Before the earthquake, the maximum shear strain rate and the principal strain rate near the epicenter increased, indicating that the stress adjustment phenomenon occurred near the epicenter and the shear effect is enhanced.

We propose a new method of using information diffusion function to construct regular matrix. Firstly, only the parametric model part of the semi parametric model is retained, and using the least square estimation we obtain the least square residual of the parametric model. Then, we use the residual vector as a signal to calculate the information diffusion function estimation of the signal. Finally, we use the calculated information diffusion estimation as the main diagonal element of the regular matrix to construct the regular matrix. Compared with the time series method, the new method desalinates the requirements for the continuity and smoothness of the signal, and the information diffusion function estimation essentially obtains the probability distribution of the residual, which is equivalent to reasonably determining the weight matrix of the signal in advance, thus making the parameter estimation robust. The semi-parametric crustal deformation analysis results of the north China block in Chinese mainland show that the new method has obvious advantages.

We test and analyze the soil layer test, equivalent shear wave velocity and microtremors of strong vibration stations in Hubei earthquake early warning network, calculate the superior frequency and RMS of acceleration, and compare the site types using equivalent shear wave velocity and predominant frequency. The results show that: 1) The RMS of acceleration of all stations meets the requirements of the technical guidelines for basic station site selection of the national early warning project, which is less than 0.01 m/s². 2) There is a big difference between the predominant frequency calculated by shear wave velocity and microtremors test in the analysis on site type. The predominant frequency of microtremors test is higher than that calculated by shear wave velocity. Therefore, various testing and analysis methods should be integrated in the classification of site types in the future. We further determine regional site types by combining borehole data and measured shear wave velocity.

We use the seismic waveform of Hubei seismic network as the data set and the most widely used PhaseNet and EQTransformer models to pick the seismic phase; its performance and generalization ability are tested and evaluated. The results show that for P waves, when the phase probability threshold is 0.1 or 0.3, PhaseNet has a better recall rate than EQTransformer and can detect more microseismic events. Although the recall rate of EQTransformer is slightly lower, the precision rate is higher. The pickup effect of S wave is poorer than that of the P wave. Although the precision rate of PhaseNet is lower than that of EQTransformer, its recall rate is significantly higher, and the F₁ value can also be maintained at about 0.8, which has a relatively stable picking performance. We further analyze the relationship between the picking results of the two models and the epicentral distance, signal-to-noise ratio and magnitude of the event. The results show that the phase-picking effect of PhaseNet has a strong correlation with the epicentral distance and the signal-to-noise ratio, but little relationship with the magnitude. The influence of EQTransformer on the signal-to-noise ratio is relatively strong; the higher the signal-to-noise ratio, the better the pickup effect, and the lower the influence on the epicentral distance and magnitude.