大地测量与地球动力学
 
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2014 Vol.34 Issue.6
Published 2014-12-09

1 REVIEW OF REGIONAL STRESS STATE OF TANLU FAULT BELT
Li Kaiyang,Wang Chenghu,Xing Borui,Li Feng

The research findings about regional stress state of Tanlu fault belt were summarized,including the maximum stress directions and magnitudes,the stability of regional faults and dynamic mechanism.The maximum stress direction is NEE in the north segment,and the southern segment,and nearly EW in the middle segment.The fault zone is mainly controlled by the Pacific Ocean plate and East Asia plate.The review shows the whole stress state of Tanlu fault zone,which provides basis for the future research on taking precautions against earthquake.

2014 Vol. 34 (6): 1-8 [Abstract] ( 1371 ) PDF (1308 KB)   ( 2566 )
9 CHARACTERISTICS OF DEFORMATION ANOMALIES IN SHANDONG 
BEFORE LAIZHOU M4.6 EARTHQUAKE
Li Jie,Zhu Chenglin,Feng Zhijun,Wang Qiang,Yan Deqiao,Sun Hao

The leveling data crossing fault in Changjiazhuang,the NS component of tiltmeter in Yantai and gravity data in Taian before Laizhou M4.6 earthquake were analyzed.The result shows that each of the 3 kinds of observation data appeared midterm or shortterm trend abnormities.The characteristics of the abnormities is:the closer of the distance from epicenter,the earlier it occured,and the farther from epicenter,the longer it lasted for.The distance away epicenter of the farthest abnormal point reaches 276 km,and the abnormities are connected to the geological structure.

2014 Vol. 34 (6): 9-13 [Abstract] ( 1245 ) PDF (926 KB)   ( 2385 )
14 ANALYSIS OF OBSERVATION DATA OF WATERTUBE TILTER AND 
EXTENSOMETER BEFORE 2013 MINXIANZHANGXIAN EARTHQUAKE
Tang Jiuan,Shen Xuzhang,Gao Antai

The data of 26 channel watertube tilter and extensometer at 6 permanent stations located around the epicenter of 2013 MinxianZhangxian earthquake with Ms 6.6 during the period of January 1,2009 and July 21,2013(one day before the MinxianZhangxian earthquake)were analyzed.The raw data were preprocessed and tidal analyzed,and the quality of the observation was estimated.The tidal response parameters and the smoothed day averaged value were obtained.The relationship between dynamic characteristics of the deformation rates and the earthquake were discussed.

2014 Vol. 34 (6): 14-19 [Abstract] ( 1245 ) PDF (1121 KB)   ( 2308 )
20 ANALYSIS OF INFLUENCES OF FAULT SLIPPING DISTRIBUTION 
AND DISLOCATION MODEL
Wang Shuai,Zhang Yongzhi,Jiang Yongtao,Yao Zhijun, Liu Guoshi

The coseismic displacement caused by Wenchuan earthquake(Ms8.0)was calculated with four seismic slip models using halfspace(Okada)and spherical dislocation theory(Shen et al),respectively,and the displacement field calculated and the observation result were compared.Statistical significance caused by fault slipping and dislocation models were analyzed using the method of twofactor variance.Results show that coseismic displacements calculated by the spherical dislocation model is consistent with the observation results,the mean value of residual is 0.007 m,and its trace is 0.006 m.Near the fault rupture,both slipping factor and dislocation factor  causing larger mean square deviation,the maximum is S2A=7.170 16 m2,S2B=91.407 7 m2,respectively.The significant influence of slipping distribution and dislocation model shows the characteristics of different space distribution,the former is embodied in the near field area,while dislocation model is mainly embodied in the farfield region.

2014 Vol. 34 (6): 20-25 [Abstract] ( 1284 ) PDF (1876 KB)   ( 2489 )
26 SIMULATION OF COSEISMIC GRACITY CHANGE AND DEFORMATION 
FOR 2010 QINGHAI YUSHU EARTHQUAKE
Zhao Yunfeng,Zhu Yiqing,Liang Weifeng,XuYunma,Guo Shusong,Liu Fang,Liu Lian

Coseismic gravity change and deformation in layer viscoelastic medium caused by Yushu Ms7.1 were calculated using PSGRN/PSCMP based on different fault slip models.The results show that:1)Coseismic gravity change and displacement calculated for teleseimic waveform based on the fault slip model are more consistent with results from field survey;2)Coseismic gravity change only locates near by faults,and the range influenced by coseismic horizon displacements are obvious widely than that by coseimic gravity change;3)The obsolute gravity change during the period of two years before the earthquake and one month after the earthquake  is obvious different from the result calculated,which indicats that observed obsolute gravity change implies earthquake preparation and coseismic change and postseismic change.

2014 Vol. 34 (6): 26-31 [Abstract] ( 1092 ) PDF (2143 KB)   ( 2978 )
32 STUDY ON NORMAL GRAVITY FIELD CORRECTION METHODS
Chen Xiaohui,Zhang Jianzhong

“Standard of Regional Gravity Survey” of China and “New Standard of the North American Gravity Correction” adopt both height correction and altitude correction.Li and Gotze derived an exact formula for computing the normal gravity values at any point in space.These three methods were compared by calculating the normal gravity values on the earth’s surface in China and its neighboring areas.The result indicates that the error calculated using the method adopted by “Standard of Regional Gravity Survey” of China is larger than the others,and the maximum error reaches 0.24×10-5 m/s2.The error is not a systematic one,it varies complexly,and closely relates to the terrain.

2014 Vol. 34 (6): 32-36 [Abstract] ( 1168 ) PDF (1852 KB)   ( 2396 )
37 THE RELATIONSHIP BETWEEN GPS VERTICAL COMPONENT,
RAINFALL AND GROUNDWATER IN QIONGZHONG STATIONS
Gu Shenyi,Wang Huilin,Zhang Fan

The relationship between precipitation,groundwater level and vertical component  of GPS fixedobservation time series of images in Qiongzhong stations was systematically analyzed using groundwater and rainfall observation data of Jiaji well and Xiliu well during 1999 to 2012.The preliminary results show that rainfall,groundwater level and GPS vertical component all have a year cycle,and the relationship between each others is contravariant:when rainfall increases and groundwater level rises,the GPS vertical component decreases which means the land uplifts;otherwise,when the rainfall decreases and the groundwater level declines,GPS vertical component increases which means the land subsidences.Finally,the mechanism of the GPS vertical component changes caused by the rainfall and groundwater level variation were discused.

2014 Vol. 34 (6): 37-40 [Abstract] ( 1150 ) PDF (898 KB)   ( 2414 )
41 CHANGE OF SURFACE ELEVATION  IN ANTARCTIC ICE SHEETS 
BY ICESAT MEASUREMENT
E Dongchen,Yuan Lexian,Yang Yuande,Zhang Shengkai,Xie Surui,Zhao Yun,Ning Xinguo

ICESat is the first satellite with laser altimeter.One of its purposes is to determinate the changes of Antarctic ice sheets.The repeat track analysis method was applied to calculate elevation changes of Antarctic ice sheets with ICESat GLA12 data from 2004 to 2008.The results show that the elevation changed evidently in West Antarctica,and decreased  in many parts.However,the elevation changed does not obviously in the East Antarctic inland areas,decreases in parts of the East Antarctic coasts

2014 Vol. 34 (6): 41-43 [Abstract] ( 1218 ) PDF (1393 KB)   ( 2364 )
44 PREDICTING IONOSPHERE TEC WITH THE COMBINATION OF 
SINGULAR SPECTRUM ANALYSIS AND ARMA MODEL
Lu Chenlong,Kuang Cuilin,Zhang Jinsheng,Chen Yulin

Based on the nonlinear and nonstationary characteristics of total electric contents time series,the combination of SSA method and ARMA model was proposed to predict TEC.In the combination,ARMA model is used to predict the data which had been decomposed and filtered by SSA method,and the predicted value of each component is overlaid.The results calculated by the combination for 2010TEC data show that the mean relative precision of TEC prediction for 5 days is 92% by the combination,and the accuracy is improved of 4%,comparing with individual ARMA method.

2014 Vol. 34 (6): 44-49 [Abstract] ( 1173 ) PDF (1514 KB)   ( 2299 )
50 INCORPORATING SEASONAL VARIATIONS OF GLOBAL AND 
REGIONAL TRF SOLUTIONS BASED ON GRACE MEASUREMENTS
Zou Rong,Ding Kaihua,Yang Shaomin,Wang Qi,Li Zhicai

In this study,a seasonal loading model was imported into the ITRF2008 solutions  based on GRACE(Gravity Recovery And Climate Environment)measurements to simulate hydrological loading,and comparison of the model to the original ITRF2008 for global reference frame realization was made.The seasonal components were simulated using either annual and semiannual terms or a nonparametric approach.Misfitting of the WRMS(Weighted Root Mean Squares)after 7parameter transformation calculated with the model decreases compared to that with the original ITRF2008 for more than 80% of daily GPS solutions.In general,the range of seasonal variations of daily solution at all sites is slightly larger in use of the seasonally augmented ITRF model.However,the results calculated with the model are more consistent with observed seasonal variations for 84% of the GPS sites.The findings mean that the use of the range of seasonal variations in the coordinate time series is decreased in use of ITRF2008 without seasonal terms relative to the true loading deformation,and that the results calculated with the TRF model included seasonal variations are more consistent with the observed GPS time series.

2014 Vol. 34 (6): 50-54 [Abstract] ( 1311 ) PDF (2033 KB)   ( 2290 )
55 DETECTION OF DIFFERENCE SOLUTION FOR DUAL FREQUENCY 
CARRIERPHASE AND CYCLE SLIP REPAIR  BASED ON 
PSEUDORANGE CONSTRAINT CONDITION
Wu Guidong,Tao Tingye

A carrierphase error model on the base of probability and statistics was proposed according to the differenced data of the dual frequency carrier phase.The results of examples calculated with the model show that calculation amount of determining the cycle slip is reduced greatly and the speed detection and repair of cycle slip is improved significantly.Moreover,data can be processed timely and the result is reliable.

2014 Vol. 34 (6): 55-59 [Abstract] ( 1215 ) PDF (797 KB)   ( 2241 )
60 THE LITHOSPHERIC HETEROGENITIES OF CHINA MAINLAND AND 
NEIGHBORHOOD BASED ON CRUST1.0 AND ITS CHARACTERISTICS
Jiang Yongtao,Zhang Yongzhi,Wang Shuai, Wei Yuming

A method based on the assumption of lithospheric local isostasy and CRUST1.0 model was deduced and  a map of lithospheric thickness was made.The main lithospheric structure of China mainland and neighourhood was calculated with the method.Results of analyzing the main lithospheric structure by the aspects of the regional tectonic background and the mechanism of lithospheric thinning indicate that the lithospheric structure characteristics are not only associated with the geological age of blocks,but also maybe more are influenced by regional tectonic environment and mechanism of lithospheric thinning.

2014 Vol. 34 (6): 60-65 [Abstract] ( 1293 ) PDF (1884 KB)   ( 2206 )
66 STUDY ON RECOVERING EARTH’S GRAVITY FIELD WITH 
GOCE’S SST-HL DATA
Liu Xiaogang,Sun Wen,Li Xinxing,Zhou Rui

A practical mathematic model was established based on the least squares method and spherical harmonic analysis method for solving the EGM from disturbing potential data.The results show that there are some influences on the EGM results when the observation data are in different data quantity and sampling rate.The precisions of the EGMs recovered with different resolutions are different between each others.The result recovered with the spherical harmonic analysis method is better than that with the least squares method.

2014 Vol. 34 (6): 66-71 [Abstract] ( 1277 ) PDF (1819 KB)   ( 2282 )
72 ANALYSES OF TOMOGRAPHY RESULTS FOR THE IONOSPHERIC 
TEMPORAL-SPATIAL CHARACTERISTICS IN LOW-LATITUDE REGION
Wen Debao,Lü Huizhu,Zhang Xiao

3 D temporalspatial variation regularity of ionospheric electron density were reconstructed by using the ionospheric tomography technique for the GNSS data of 126 stations on 10 June,2005.The diurnal variation regularity of ionospheric electron density distribution and variation characteristics of the ionospheric vertical structure in lowlatitude region were investigated and the prosess of occurrence,development and disappearance of the equatorial anomaly structure were carefully analyzed.The factors that impact the accuracy of ionospheric electron density were discussed,and some suggestions were given for further investigation of ionospheric tomography technique.

2014 Vol. 34 (6): 72-75 [Abstract] ( 1060 ) PDF (1392 KB)   ( 2269 )
76 SIMULATION AND INVERSION OF GNSS IONOSPHERIC OCCULTATION 
OBSERVATIONS——THREE FREQUENCY
Hu Chuan, Chen Yi

GNSS radio occultation technique has been proved to be an important method to investigate the ionospheric electron density in different levels.3D ray tracing is the best choice for analyzing the propagation of ray in ionosphere.A group of matrix equations from the differential equation in Cartesian coordinate was used to analyze the detail steps of ray tracing with the formulas.The NeQuick model is used to simulate the excess phase of L1,L2 and L5,and the simulated results are used to retrieval the electric density profile with absolute TEC inversion method with different band combination.The result of two numerical experiments shows that the combination L1-L5 is the preferable choice for vertical density profiles inversion under the identical observation conditions.

2014 Vol. 34 (6): 76-80 [Abstract] ( 1224 ) PDF (1380 KB)   ( 2479 )
81 STUDY ON POSITIONING WITH DIFFERENTIAL NETWORK  OF BDS/GPS
FUSION SYSTEM BASED ON MULTIPLE CORS REFERENCE STATIONS
Li Hefeng,Bei Jinzhong,Dang Yamin,Wu Renhong,Wang Shijin,Liu Guozhi

Performance of positioning with differential network of BDS/GPS fusion system was analyzed using pseudorange information through multiple reference stations differential positioning technology,based on BDS/GPS CORS test system.The experiment results indicate that positioning accuracy with multiple reference station BDS/GPS fusion system of single epoch realtime is not larger than 1 m,40 epoch realtime moving average positioning accuracy is  about 0.5 m,pseudorange positioning accuracy is improved greatly.The method can meet demand of users for navigation and positioning.

2014 Vol. 34 (6): 81-85 [Abstract] ( 1252 ) PDF (2174 KB)   ( 1916 )
86 GLOBAL IONOSPHERIC TEC PREDICTION BASED ON 
LEAST-SQUARES COLLOCATION METHOD
Zhang Qiang,Zhang Hongping,Zhao Qile,Huang Ling

The global ionospheric model for longterm prediction and shortterm prediction was analyzed through dividing the vertical total electron content(VTEC)into deterministic component and signal component,fitting the filtered signal of autocovariance function using 4order autoregressive model,and using the LeastSquares Collocation method.The results show that correlation coefficient between longterm prediction of trend component and global ionospheric model of CODE is 0.812,and the residuals between model fitted values for daily mean global total electron content(mean global TEC,MGTEC)and reference values are less than 4 TECu.The results of shortterm prediction show that the prediction precision is lower in the Southern Hemisphere than that in Northern Hemisphere,and the prediction precision is the lowest in the region between 20°N and 20°S of geomagnetic equator and in the ocean areas.Global prediction precision RMS is about 1-7 TECu,the average precision is about 2.4 TECu in Northern Hemisphere,and is
about 3.5 TECu in Southern Hemisphere.

2014 Vol. 34 (6): 86-91 [Abstract] ( 1238 ) PDF (3083 KB)   ( 2203 )
92 A NEW METHOD FOR PRECISION EVALUATION OF KINEMATIC 
GNSS POSITIONING
Liu Weiping,Hao Jinming, Lü Zhiwei

A method based on the algorithm of coordinate transfer for precision evaluation of dynamic GNSS positioning was proposed.The method was validated with some examples.The results show that the precision with the algorithm of coordinate transfer is better than 1cm considering the influences of all kinds of errors.

2014 Vol. 34 (6): 92-96 [Abstract] ( 1173 ) PDF (1436 KB)   ( 2382 )
97 THE APPLICATION OF ROBUST EKF ALGORITHM BASED ON 
VONDRAK GROSS ERROR DETECTION TO GPS NAVIGATION
Zhang Liang,Gao Jingxiang,Li Zengke and Wang Jian

For there is the problem of iterative calculation in robust extended Kalman filter(EKF),an algorithm of robust EKF based on the Vondrak gross error was proposed and applied to the GPS navigation and positioning.The first,it could identify and position the gross error of observations.Then,robust EKF model was used.In order to test the new model,dynamic GPS data was measured,double difference observation equation and velocity with acceleration kalman state equation of the model were built.The experiment results show that the new differential robust EKF model can resist the influence of gross errors in observation.Compared to the traditional robust EKF model,it can avoid resistance difference iteration in each epoch,and improve the efficiency of navigation solution.

2014 Vol. 34 (6): 97-101 [Abstract] ( 1264 ) PDF (1416 KB)   ( 2282 )
102 CORRECTION OF STRATIFIED ATMOSPHERE DELAY 
INSAR INTERFEROMETRY
Gu Zhaoqin,Gong Huili,Zhang Youquan,Du Zhaofeng,Liu Huanhuan,Wang Sa,Lu Xuehui

Atmospheric delay is one of the main limiting factors for extracting groundsurface deformation with small rate over a large area with Interferometric Synthetic Aperture Radar(InSAR)technology.The delay consists of two components:the stratified component and the turbulent component.Stratified atmosphere delay can be plagued by both orbital error and deformation signal.It is difficult to separate this component by traditional interference methods.The residual error of stratified atmosphere delay sometimes could reach the range of deformation  in some regions,which seriously impacts the accuracy of SAR interferometry measurement.A multiscale decomposition technique is proposed to evaluate stratified atmosphere delay,based on recognition of atmospheric components using North America NARR model.The results demonstrate that the method can effectively reduce the stratified components in InSAR interferometric phase.

2014 Vol. 34 (6): 102-108 [Abstract] ( 1263 ) PDF (2319 KB)   ( 2174 )
109 COMPARISON OF GRAVITY FILED MODELS BASED ON GOCE DATAS
Zheng Zengji,Cao Jianping,Fan Lihong, Han Meitao

The precision of gravity filed models established on GOCE data were compared and analysed according to geoid errors degree variances and degree variances of potential coefficient.The results indicate that:1)The precision of GOCEonly models is an order of magnitude higher  than GRACEonly models,between 150 and 180 degree.2)The accuracy of gravity filed models which based on direct approach is highest,followed by timewise approach and the minimum is spacewise approach.3)At present,the maximum degree of earth gravity filed models which derived from GOCE datas is 250 and the accumulative geoid errors degree variances at 250 degree is about 14.7 cm.

2014 Vol. 34 (6): 109-113 [Abstract] ( 1209 ) PDF (1050 KB)   ( 2255 )
114 PRINCIPLE AND PRECISION ANALYSIS OF BDS ABSOLUTE 
VELOCITY DETERMINATION
Liu Zhaoying,Chen Guo,Zhao Qile,Hu Zhigang, Qu Lizhong

The principle of velocity measurement using Beidou System(BDS)was introduced,the effects of each error correctionon on single point velocity measurement was analyzed and corresponding correction formulas were proposed.At last,the accuracy of BDS was evaluated according to the results of the experiments in which the results from dynamic velocity measurement and low dynamic velocity measurement were simulated using static data.The experiments show that the accuracy can reach cm/s in the simulation using Doppler Velocity Measurement Principle,and the accuracy can reach mm/s in the simulation using Doppler observation results derived by carrier phase.In low dynamic testing experiment,the mutual deviations between original Doppler velocity measurement results and integrated navigation equipment velocity measurement accord with cm/s level.While the mutual deviations between derived Doppler velocity measurement results and integrated navigation equipment velocity measurement accord with dm/s level.It can be concluded that the results from integrated navigation equipment are obviously affected by the motion of carriers.

2014 Vol. 34 (6): 114-118 [Abstract] ( 1107 ) PDF (1036 KB)   ( 2302 )
119 THE ROBUST ESTIMATION BASED ON MEAN SHIFT MODEL
Wang Yanting,Gui Qingming, Tian Xinlai

The mean shift model for robust estimation and a new robust estimation model were proposed in the paper.In the use of the robust estimation model,it is unnecissary to change weight matrix for avoiding appearance of the rank deficient matrix.This method is suitable for processing of observation data.Examples show that the proposed method has good robustness.

2014 Vol. 34 (6): 119-121 [Abstract] ( 1185 ) PDF (471 KB)   ( 2193 )
122 THE RIGOROUS ROBUST SOLUTION OF LOWALTITUDE 
SENSOR DISTORTION PARAMETERS
He Haiqing, Huang Shengxiang

The rigorous robust solution of lowaltitude sensor distortion parameters was proposed.Firstly,the initial parameters are obtained by 2D DLT,then the location of reference objects with gross or deviation is restrained by Huber algorithm.Finally,the rigorous solution of sensor distortion parameters is carried out by iterative computation with constrained condition.Experimental results show that the solution is reliable and practical,and the precision is higher than the bundle adjustment with unit weight or selecting weight iteration

2014 Vol. 34 (6): 122-125 [Abstract] ( 1042 ) PDF (584 KB)   ( 1945 )
126 STUDY ON ADAPTABILITY OF GPS ELEVATION FITTING MODELS
UNDER DIFFERENT TERRAINS
Dong Shuxiao,Gan Shu

A combination model based on the removerecovery principle was proposed.The model was established according to structure characteristics of each model,and analysis results of adaptability of the model under different terrain conditions of various engineering examples.The model is suitable to different terrain conditions.

2014 Vol. 34 (6): 126-130 [Abstract] ( 1152 ) PDF (911 KB)   ( 2483 )
131 STUDY ON PROPERTIES OF NOISE ANALYSIS WITH ALLAN VARIANCE
Xue Xueming

Aimming at white noise,flicker noise,random walk and 1storder GaussMarkov process,the effect of  inherent properties of the random sequence,including data length,sample rate,discontinuity of data and gross error,on the result of Allan Variance was analyzed in detail.The experimental results suggest that each property of random sequence affects the result of Allan variance in different degree.The author suggests a method for analyzing INS data.

2014 Vol. 34 (6): 131-134 [Abstract] ( 1136 ) PDF (1079 KB)   ( 2421 )
135 SELF-ADAPTIVE SPECTRUM CORRECTION LU DECOMPOSITION 
ALGORITHM FOR SOLVING A NORMAL EQUATION WITH 
SEVERELY ILLCONDITIONED MATRIX
Deng Xingsheng, Sun Honghong

The spectrum correction iterative algorithm and its correction algorithm are not a good solution to serious illposed problem,for the contradiction between convergent speed and illcondition reducing is difficult to deal with.At currently,the damping factor used by the improved algorithm still lacks an effective method to determinate.Aiming at this problem,the selfadaptive spectrum correction LU decomposition algorithm was proposed in the paper.The algorithm,which based on the spectrum correction equation,can avoid the matrix inverse problem by using the LU decomposition method for solving a normal equation.In the process of iteration,the damping factor is not fixed,and its value is adjusted adaptively according to the rate of residual decline.Examples show that,the algorithm can greatly reduce the iteration times to solve a normal equation with severely illconditioned matrix,and it also enhances the convergent speed and calculation accuracy greatly.

2014 Vol. 34 (6): 135-139 [Abstract] ( 1310 ) PDF (603 KB)   ( 2338 )
140 RESEARCH OF ROBUST ADAPTIVE FILTERING BASED 
ON MOVING WINDOW
Liu Maohua,Yin Xiao,Lü Zhipeng,Wang Yan

Robust adaptive filtering supposes that result of robust least square is accurate in current epoch.Through discrepancy between updated kinematic information and the measurements,navigation is adaptive.But in actual car navigation,rate of gross error is high,which makes accuracy of robust result drop.In order to solve this problem,this paper gives a robust adaptive filtering based on moving windows which regard mean error of robust least square solution of previous epochs as the threshold of current epoch.Experiments of road based on GPS/COMPASS realkinematic positioning indicate that this algorithm can improve accuracy of navigation in urban environment.

2014 Vol. 34 (6): 140-143 [Abstract] ( 1161 ) PDF (739 KB)   ( 2392 )
144 ANALYSIS OF GYROSCOPE RANDOM ERROR AND 
APPLICATION ON GNSS/INS INTEGRATION
Hao Wanliang,Sun Fuping

In order to reduce gyroscope random error,wavelet transform and higherorder AR models were used to process GNSS/INS data.The most of high frequency noise was eliminated by wavelet analysis,and higherorder AR model was used to describe the correlated noise.The results indicated that the method was effective for improving navigation accuracy during GPS outage.

2014 Vol. 34 (6): 144-147 [Abstract] ( 1244 ) PDF (1038 KB)   ( 2189 )
148 SOLVING MOLODENSKY’S WITH ELLIPSOID FUNCTION
Zhang Chijun,,Luo Mingjin,Liu Lintao,Fang Jian,Tang Yuanyi

For a harmonic function in outer space,ellipsoid lay outside the disturbance T(u,θ,λ) can be expressed by a series of harmonic functions ellipsoid,said to T(u,θ,λ) along the normal(n)direction derivation,only to the various series contains u factor derivation Qmn(u),and contain the factors:u,θ,λ include remain Tmn(b,θ,λ) unchanged(including b for constant).T〖SX(〗T〖〗n〖SX)〗,the linear combination of,unobserved ground ellipsoid coordinate u,θ,λ,can be used to establish respectively the first second and third boundary value equation,end for boundary conditions that observation of the surface of the earth,then the other end the series and generative Taylor series of Δu,including Δu=u-b.Due to the boundary conditions and  Δu are known,then the equation of the ellipsoid Tmn(b,θ,λ) can be solved ,and then the disturbance (uR,θ,λ) on the ground point or in outer space are calculated.As the ellipsoid is not used as the sphere,and ellipsoid function and the series solution are used,the results with the solution are closer to the actual the earth.Moreover,the method combining ground observation data(such as elevation)can avoid difficult of the changeable in use of a single layer’s inclination.

2014 Vol. 34 (6): 148-156 [Abstract] ( 1295 ) PDF (759 KB)   ( 2142 )
157 A NEW LAND-BASED AIRCRAFT PRECISION APPROACH BASED ON PPP
Zheng Kun,Gao Xiang,Li Xiaoyu, Jia Ruixi
A new landbased aircraft precision approach based on precise point positioning technology was proposed,which can support the blind landing of fixedwing aircraft,helicopters and unmanned aerial vehicles.The approach can reduce the risk of landing in bad weather and greatly simplifies the airport equipment and reduce the cost of construction of the airport.Moreover,a precise ephemeris compression method was presented in the paper,which can meet two hours of precise point positioning using two Beidou short messages.
2014 Vol. 34 (6): 157-161 [Abstract] ( 1117 ) PDF (956 KB)   ( 2363 )
162 APPLICATION OF THE OPTIMAL NON-NEGATIVE VARIABLE WEIGHT 
COMBINATION MODEL FOR MONITORING DAM DEFORMATION
Ren Chao,Liang Yueji,Pang Guangfeng,Yang Xingyue

Dam deformation is nonlinear,nonstationary and random which makes it difficult to accurately predict the deformation.Based on three kinds of single model,gray GM(1,1),BP neural network and the common Carl filtering,the optimal nonnegative variable weight combination forecasting model was proposed.The model inherited the advantages of each single model.It is optimal for local prediction and  accuracy is higher for the global prediction.The calculation results were compared with the optimal weighted combination model and each single one.The results show that the model prediction accuracy is higher;the root mean square error is 0.11 mm.And it can be applied to dam deformation prediction practically.

2014 Vol. 34 (6): 162-166 [Abstract] ( 1110 ) PDF (695 KB)   ( 2266 )
167 TUNNEL DEFORMATION ANALYSIS USING KNNS-ICP METHOD 
BASED ON TERRESTRIAL LASER SCANNING DATA
Feng Fajie, Liu Huiwu

A method for analyzing tunnel deformation with the terrestrial laser scan(TLS)data based on the KNNSICP closing algorithm was proposed in the paper.First,the tunnel point cloud in the same area is extracted after registration.Second,the initial rotation and translation matrix are setted to unit and zero.The same slice of point cloud is closed by KNNSICP.At the last,the errors of corresponding points are calculated and the threshold is determined.The threshold is employed to extract the abnormal points before and after the deformation.The tunnel deformation would be determined by analyzing the changes of abnormal points.The results demonstrate the validity of the proposed method according to the example.

2014 Vol. 34 (6): 167-172 [Abstract] ( 1224 ) PDF (2097 KB)   ( 2149 )
173 A REMOTE CALIBRATION SYSTEM FOR CBT-TYPE 
BOREHOLE-TILTMETER BASED ON STEPPING MOTOR
Li Tao,Wu Liheng,Chen Zheng,Li Hong

A in-situ calibration of CBT-type borehole-tiltmeter was designed for correctly understanding the drilling state.The remote calibration system takes  RS-485 bus,as the basis and takes the stepper motor as the core.It is realized to calibrate remotely the sensors grid valued and linearity of the CBT-type borehole-tiltmeter.

2014 Vol. 34 (6): 173-176 [Abstract] ( 1055 ) PDF (914 KB)   ( 2263 )
177 A NEW TYPE OF SENSOR FOR THE BOREHOLE STRAINMETER
Wu Shugui

A new type of micro displacement measurement sensor  was introduced.The sensor can solve the shortcomings of the existing borehole strainmeters,and improve the reliability and  the observation accuracy borehole strainmeter.

2014 Vol. 34 (6): 177-179 [Abstract] ( 1067 ) PDF (1369 KB)   ( 1988 )
180 STUDY ON INDOOR VERIFICATION METHOD OF DIGITAL LEVEL
Li Wenyi,Cheng Zengjie,Zhao Lijun,Su Guoying

The purpose and the process of method validation of indoor verification of digital level were introduced.The measurement results,including eigenvalues precision,accuracy,uncertainty,were analyzed.The results of indoor and outdoor verification were compared.Statistical data indicate that the method is effective,and can be used as an alternative method for outdoor verification.

2014 Vol. 34 (6): 180-182 [Abstract] ( 1094 ) PDF (424 KB)   ( 2104 )
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