The basic principle of spectral combination method is discussed,and the general expressions of the spectral weight and spectral combination of the united-processing of various types of gravimetric data are shown.What’s more,based on degree error RMS of potential coefficients,the detailed expressions of spectral combination formulae and the corresponding spectral weights in the Earth’s gravitational field model（EGM） determination using GOCE + GRACE and CHAMP + GRACE + GOCE are derived.The fundamental situation that ulux-champ2013 s,tongji-GRACE01,go-cons-gcf-2-tim-r5 constructed respectively by CHAMP,GRACE,GOCE data and go-cons-gcf-2-dir-r5 constructed by syncretic processing of GRACE,GOCE and LAGEOS data are explained briefly,the degree error RMS,cumulative geoid height error and cumulative gravity anomaly error of these models are calculated.A syncretic model constructed from CHAMP,GRACE and GOCE data,which is expressed by champ + grace + goce,is obtained based on spectral combination method.Experimentation results show that the precision of CHAMP data model is the lowest in satellite-only models,so it is not needed in the determination of syncretic models.The GRACE data model can improve the GOCE data model in medium-long wavelength,so the overall precision of syncretic model can be improved.Consequently,as many types of gravimetric data as possible should be combined together in the data processing in order to strengthen the quality and reliability with widening scope and improve the precision and spatial resolution of the computational results.

The error models of cumulative geoid height influenced by the errors of intersatellite range,range rate of KBR system and the satellite position of GPS receiver are deduced respectively.The combined error model of cumulative geoid height influenced by range rate error and satellite position error is also constructed.The results show that the precision indexes of inter-satellite range,range rate of KBR system are about 0.64×10-6 m,0.8×10-6 m / s,respectively.While the precision indexes of satellite position of GPS receiver is about 2.1cm.The cumulative geoid height error of Earth ’ s gravity field model in 120 degree,which is recovered by the combined error model,is 26cm in the presence of these precision indexes.

Gravity-aided inertial navigation is a technique that makes use of gravity to correct inertial navigation error of underwater vehicles. Matching algorithm is vital in the process of gravity-aided inertial navigation. An object function model of differential descending weight-correlation was put forward based on the principle of mean square deviation. Because of the influence of random errors, there are multi-available positions determined by the object function model which are around the real position with different probabilities. Then, a probabilistic data association filter (PDAF) algorithm was proposed. Navigation position determined by PDAF is much closer to the actual one than that chosen by the nearest neighbor method, the reliability and the anti-jamming of the algorithm are improved. Then, the effect of the serial sampling intervals on the matching precision was discussed. Through simulations in the experimental area, the results showed that navigation errors were corrected effectively with proper sampling intervals and sampling lengths based on the algorithm.

The non-singular computational formulae of the first-and second-order derivatives of the Legendre functions of the colatitude and the m P-n m(cos θ)/sin θ are introduced,and the non-singular computational formula of m2P-n m(cos θ)/sin2 θ is also deduced.When taking the non-singular computational formulas of the first-and second-order derivatives of the Legendre functions of the colatitude and the m P-n m(cos θ)/sin θ,m2P-n m(cos θ)/sin2 θ into the computation of each component of the disturbing gravity gradients,the complex situation that the m equals to 0,1,2,and any other numerical values are also considered,and the non-singular particular computational models of each component of the disturbing gravity gradients are constructed.The simulation experimentation shows that the particular computational models constructed in this paper not only completely fulfill the precision demand of the computation of the current satellite gravity gradients,but also the models are steady,credible and easy to be programmable realized.

Based on the continuation property of the Earth's gravity field,the Coons curved surface modeling of computer graphics was introduced into the reconstruction of the marine gravity anomalies map for navigation,and both the bilinear Coons curved surface gravity anomaly model and bi-cubic C1Coons curved surface gravity anomaly model for different boundary curves were established.Through the analysis of data within experimental area,results showed that the accuracy of gravity anomaly model based on Coons curved surface was better than that based on moving surface fitting model.Based on the global SRTM30″plus oceanic depth data,the reconstruction of gravity anomaly map based on Coons curved surface using Bouger anomaly was made,and the accuracy was improved by 25% compared with the direct modeling using free air gravity anomalies.

Landslide is a kind of serious geologic disaster. It's very important to monitor the deformation of the landslide area that threatens the lives or constructions. There are some successful applications in deformation monitoring using GPS. In certain circumstance, the continuous observation and real-time 3D coordinates with high precision can be carried out automatically using GPS. However, most of the landslide areas lie in canyons where the signals from GPS satellites are sheltered seriously. So in this case, to get precise and reliable results in deformation monitoring using GPS is a problem which needs being discussed and solved. In this paper, the landslides monitoring project in the Kala Reservoir area using GPS in China is introduced firstly. The design of deformation monitoring GPS network and the data processing method are discussed subsequently. The results of the deformation monitoring indicate that the requirements of the project are accomplished.

The steps and methods of application Surfer in visualization of earth gravity field data is described.Considering the characteristics of gravity field data,Surfer is operate directly to draw isoline or 3D maps by only making a simple data conversion program.The real-time visualization of earth gravity field data is realized.