The resolution of ambiguity for long range reference stations at single epoch and the method of getting undifference regional error correction and an algorithm of dynamic ambiguity resolution on rover at single epoch were introduced in the paper.The test results using actual measurement data indicate that the rover position at centimeter level can be got by use of the algorithm at single epoch for long range Network RTK.

A rigorous model extracting the 3D dimension deformation field by integrating the multiple aperture interferometry (MAI）data and the conventional InSAR data along both ascending and descending orbits for was proposed in the paper.The coseismic deformation field caused by the 2003 Bam earthquake (Iran）was selected as the testing site，and the 3D deformation field derived with the model is compared with the existing fault model and the azimuth offsets (AZO）derived by coregistration of amplitude images.The testing results indicate that the azimuth displacement derived by MAI is improved in terms of accuracy and computation efficiency，and the 3D coseismic displacement is consistent with the fault model.The root mean square error (RMSE）between the two types of results are 2.7，4.1 and 3.2 cm in vertical，northsouth and eastwest direction，respectively.

The carrier phase smoothing is generally used to reduce the influence of multipath effect and measurement noise in reginal area augmentation system，and only single frequency pseudorange observations are used in the divergencefree smoothing.A smoothing scheme based on the linear combination of code measurement for redusing theinfluence of multipath effect，and improving the accuracy of Beidou code differential position，is proposed in this paper.The results calculated with the new method for real data was show that the position accuracy is significantly improved.

By taking the smallest standard deviation of cycleslip as the standard，the wavelength of phase combination and amplification factor of ionospheric delay as the constraint condition，a linear independent carrier phase combinations for Beidou are selected.Combining with the theory of multifrequency cycleslip detection，and according to the feature of three kinds of satellites within Beidou Navigation Satellite System(BDS)，the performance of cycleslip detection in the case of different types of satellites is discussed.By using Beidou triplefrequency observation data，the performance of cycleslip correction is verified.The result shows that proposed method can detect and repair cycleslips of triplefrequency undifferenced observations of GEO and IGSO satellite.And cycleslips of observations of MEO satellite can be detected and repaired in case of high data rate.

Precise point positioning (PPP) accuracy of compass and GPS was compared using the data from Rongcheng,Xiaguan,Yanchi,Tangshan and Zhenzhou,with PANDA software.The results show that: Beidou navigation PPP accuracy in horizontal direction is 12 cm,in vertical direction is 34 cm;GPS PPP accuracy in horizontal is less than 1 cm,and in vertical direction is about 12 cm.Although the PPP accuracy of the Beidou navigation system is 50% lower than the PPP accuracy of GPS,it is suitable for use in  the fields in which requirement of accuracy is not high.

The IBIS-L ground-based SAR monitors the displacement of an observed object by combining of the stepped frequency continuous wave, synthetic aperture radar and an interferometry technique. To monitor the displacement after the landslide in Dashuchang town on September 1, 2014, we first discuss the key technology of the IBIS-L ground-based InSAR and the ground-based SAR system. Second, we summarize InSAR data processing flow. Then third, obtain displacement evolution characteristics with sub-millimeter precision and high spatial-temporal resolution. GB-InSAR results show that displacements of the middle-upper parts on the left and right sides of the landslide body are 120 mm and 75 mm respectively. This is caused by crack water and rain. Displacements of landslide body are impossible to produce larger secondary geological disasters.