大地测量与地球动力学
 
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2010 Vol.30 Issue.4
Published 2010-09-20
地壳形变与地震
1 CHARACTERISTIC ANALYSIS OF DYNAMIC GRAVITY CHANGEBEFORE YUTIAN Ms7.3 EARTHQUAKE, 2008
Shen Chongyang;Li Hui;Sun Shaoan;Yang Guanliang;Xuan Songbai;Tan Hongbo;and Liu Shaoming;
On the basis of the data and results of the repeated gravity observation network in Chinese mainland since 1998, the evolution characteristics of dynamic gravity field changes in the seismogenic region before Yutian Ms7.3 earthquake in Mar, 2008 has been analyzed and summarized. The dynamic evolution images of regional gravity field reflects the middlelong term (two to ten years) essential information during the earthquake preparation. The notable gravity symbols of the earthquake preparation are positive gravity change (rise) lasted for many years and relatively largescale gradient zone of gravity change that the former is in favor of continuous accumulation of seismic energy and the latter makes for occurrence of seismic rupture. The related gravity change during the process of the earthquake preparation have the characteristics: increaseaccelerated increasedecelerated increas which is similar to that of Tangshan Ms7.8 earthquake in 1976. The maximum accumulative gravity change related to the earthquake can reach 200×10-8 ms -2 .
2010 Vol. 30 (4): 1-7 [Abstract] ( 1720 ) PDF (1986 KB)   ( 2634 )
8 VARIATION OF GRAVITY FIELD BEFORE AND AFTERPANZHIHUA Ms6.1 AND YAOAN Ms6.0 EARTHQUAKES
Zhu Yiqing;Guo Shusong ;and Liu Fang

The repeatedly gravimetric data in western area of Yunnan Province are analyzed. The dynamic evolution characteristics of gravity field in the seismogenic process of the Panzhihua Ms6.1 earthquake on Aug. 30,2008 in Sichuan Province and Yaoan Ms6.0 on Jul. 9,2009 in Yunnan Province are studied and the following conclusions are drawn. 1)The gravity observations reflected the precursory gravity information during the seismogenic process, the dynamic evolution pattern of gravity reflects clearly the gravity field’s evolution of “quasihomogeneous→heterogeneous then earthquake→quasihomogeneous” in the process of the Pabzhihua Ms6.1 and Yaoan Ms6.0 earthquakes.2)The tendency after Panzhihua Ms6.1 earthquake are estimated and the annual prediction before Yaoan Ms6.0 earthquake are made.
2010 Vol. 30 (4): 8-11 [Abstract] ( 1708 ) PDF (778 KB)   ( 3937 )
12 ANALYSIS OF DEFORMATION OF ZHONGBA TIBET 2004 Ms6.7 AND 2005Ms6.5 EARTHQUAKES AS CONSTRAINED BY InSAR MEASUREMENTS
Du Zhibiao;Shen Qiang;He Chanjun;and Qiao Xuejun
The Envisat images from ESA were used to derive the coseismic deformation interferograms caused by the Zhongba Ms6.7 earthquake on July12,2004 and Ms6.5 earthquake on April 8,2005 occurred in Tibet. The results indicate that two earthquakes caused the deformation in an area of 20 km with a maximum LOS change about 19.0 cm and 30.5 cm recpectively. Adopting isotropic elastic halfspace dislocation model, we estimate that the two earthquakes epicenter locate at E83.71°,N30.70° with a seismic moment tensor Mw6.1 and E83.72°，N30.52° with a seismic moment tensor Mw6.2, dominated by normal fault fracture with maximum slip 1 m and 1.4 m, located at the intersection of NW Brahmaputra fault zone and the near side NS Palongcuo-Cangmucuo fault zone
2010 Vol. 30 (4): 12-18 [Abstract] ( 2377 ) PDF (2360 KB)   ( 3032 )
19 INVERSION OF SLIP DISTRIBUTION OF 2008 WENCHUANMw7.9 EARTHQUAKE CONSTRAINED JOINTLY BY InSAR AND GPS MEASUREMENTS
Zhang Guohong ;Qu Chunyan ;Wang Chisheng;Song Xiaogang;Zhang Guifang;and Shan Xinjian
A two-segment fault model for the May 12,2008 Wenchuan Ms8.0 earthquake based on field investigations and precisely relocated aftershocks had established. The model is consistent with the surface rupture traces seen in the field at most sites along the fault. It contains two fractures with linearly varied dips from 70° to 33° and from 60° to 20°, respectively and they converge into one shear belt at the depth of 28 km. Then use this fault model as the constraint to invert the coseismic slip distribution using GPS data as well as InSAR measurements solo or jointly. The results show a robust slip distribution can be obtained by jointly using GPS and InSAR data. The deformation by forward modeling matches well the GPS data and InSAR deformation, with a relatively small total RMS of 9-11 cm. The inverted slip distribution is confined to a depth range 0-20 km and the maximum slip is 10 m. Among the largest slip areas, the Beichuan area has relatively concentrated slip and shallower depth（0-10 km）than other areas. This may be the reason that the Beichuan area was most severely destroyed by the earthquake. The inverted rake distribution shows that there is a transform of fault slide along the direction of SWNE. It is primarily thrusting with some rightlateral component from nearby the epicenter to Beichuan, and changes into dominantly
right-lateral slip with little thrusting or even pure rightlateral slip at the Qingchuan area in northeast. The mean rakes range from 103°to 121°and 138°. The inverted seismic moment tensor M0 is 8.7×10 20 Nm, and the inverted moment magnitude scale Mw is 7.9.
2010 Vol. 30 (4): 19-24 [Abstract] ( 2584 ) PDF (1362 KB)   ( 3490 )
25 CALCULATION OF THREEDIMENSIONAL TERRAIN DEFORMATION OF WENCHUAN EARTHQUAKE WITH GPS AND InSAR DAT
Ban Baosong ;Wu Jicang ;Chen Yongqi ;Feng Guangcai ;and Hu Shouchao
InSAR (Synthetic Aperture Radar Interferometry) can only obtain the displacements along direction of LOS (lineofsight), it is not the real three-dimensional surface deformation. Therefore it is difficult to analyze both vertical and horizontal terrain displacements. A method combining GPS and InSAR data to calculate threedimensional terrain displacements of Wenchuan earthquake is proposed. The results show that the earthquake pupture is obviously right-leteral and thrust.
2010 Vol. 30 (4): 25-28 [Abstract] ( 1897 ) PDF (890 KB)   ( 3466 )
29 INFLUENCE OF CRUST LAYERING AND TICKNESS ONCOSEISMIC EFFECTS OF WENCHUAN EARTHQUAKE
Tan Hongbo;Shen Chongyang;and Xuan Shongbai;
Using the PSGRN/PSCMP software and the fault model
offered by USGS and on the basis of finite rectangular dislocation theory and the local layered wave velocity structures of the
crustuppermantle, the influences of crust layering and thickness to coseismic gravity changes and deformation of Wenchuan earthquake have been simulated.The results indicate that: the influences have relation to the attitude of faults and the relative position between calculated points and fault. The difference distribution form of simulated results between the two models is similar to the distribution of coseismic effect. For the percentum distribution, it’s restricted by the zero line of the coseismic effects obviously. It’s positive far from the zero line. For the crust thickness, the effect is about 10%~20%. The negative and the effect over 30% focus around the zero line. The average influences of crust layering and thickness for the longitudinal deformation, latitudinal deformation, vertical deformation and gravity changes are 18.4％、18.0%、15.8% and 16.2％,respectively when the crust thickness is 40km, the average influences are 4.6%,5.3%,3.8% and 3.8%, while the crust thickness is 70 km, the average influences are 3.5%,\{ 4.6%\},3.0% and 2.5% respectively.
2010 Vol. 30 (4): 29-35 [Abstract] ( 1826 ) PDF (2355 KB)   ( 3757 )
36 SHORT-TERM DISPLACEMENT AND CHARACTERISTICS OF STRAIN RATE OF SHANXI FAULT SUBSIDENCE ZONE
Guo Liangqian; Zhan Wei;Yang Guohua;and Bo Wanju
On the basis of the results of the strain displacement field and the principal strain rate calculated from the data observed from Shanxi GPS local area net, the smallscale deformation and strain of the various basins are researched,
as well as the overall changes of Shanxi fault subsidence zone.Meanwhile, from the observational data of the area network of network engineering, the differential activities and the strain rate resulted from the interaction of the Ordos block with the Taihang Mountains block,
within Shanxi fault subsidence zone are calculated,
which is a spatial largescale change. There are significant differences in different scales of strain field and displacement field,which are also different in the implications of earthquake prediction. Small and moderate earthquakes are more random, which are associated with the spatial smallscale deformationstrain field, the large earthquakes occur mainly in the boundary zones of block, which are associated with block movement as a whole, so the spatial smallscale deformationstrain field is the basis for assessing the activities of small and moderate earthquakes, block movement and strain fields are the basis for assessing the activities of the large earthquake. The strain during 2006-2009 shows “south compressing and north tensing” of the Datong basin and Xindai basin, “inner low and outer high” of the main strain rate of Taiyuan basin ,“north compressing and south tensing” of Linfen basin. Horizontal movement of each basin has the tensoshear or compressoshear activity. Largescale changes show a certain amount of strain in Shanxi fault subsidence zone.
2010 Vol. 30 (4): 36-42 [Abstract] ( 2156 ) PDF (2549 KB)   ( 3379 )
43 RESEARCH ON PRESENTDAY CRUSTAL MOVEMENT ANDDEFORMATION IN MIDDLE OF LHASA BLOCK FROM GPS OBSERVATION
Wang Shuangxu ;Zhang Xiaoliang ;Zhang Xi ;Wu Zhenhan ;and Hu Daogong
On the basis of the GPS measurement data in 2005—2007 along the railway in central Lhasa block, combining with the parameters of regional active faults and topographicgeomorphic character and historical strong earthquake, the characteristics of presentday crustal movement and deformation and main fault activity along the railway in the middle of Lhasa block are analyzed.
The conclusions are drawn as follows.1)The presentday horizontal movement direction of the studied area is WENEE,consistent with the Tibetan plateau movement background by the northward collision of the India block that reflects the joint action of the horizontal dynamics from both the northsouthward horizontal compression and the eastward matter flow.2)The regional apparent strain distribution manifests itself in the different mode in different zone that closely related to the crust extension deformation made and reflects the divergence of the basin extension deformation with the ‘basinmountain’ tectonic activity of pressed and rise mountainous region.3)Active velocities of the faults:F76,F67 and F50 evidently descent from S to N,in the spaces that they intersect with the NENNE faults F73 and F65 and their adjant area of high apparent strain distribution the historical seismic activity was very strong it reflects the inherit of tectonic activity and deformation.
2010 Vol. 30 (4): 43-50 [Abstract] ( 2330 ) PDF (3605 KB)   ( 2953 )
51 APPLICATION AND ANALYSIS OF GRACE SATELITE GRAVITY OBSERVATION IN MONITORING STRONG EARTHQUAKE
Xing Lelin;Li Hui;Zhou Xin;and Zou Zhengbo;
The theoretical coseismic gravity changes in the height of satellite orbit and coseismic deformation results of SumatraAdaman and Wenchuan earthquakes are simulated and calculated by using satellite gravity models, dislocation theory and up continuation technique, the characteristics of deep structures of Longmenshan fault region geophysical condition for strong earthquake occurrence are revealed.
2010 Vol. 30 (4): 51-54 [Abstract] ( 1751 ) PDF (1144 KB)   ( 3318 )
55 OUTLIER DETECTION ALGORITHM FOR SATELLITE GRAVITY GRADIENT DATA BY USING WAVELET SHRINKAGE DENOISING
Wu Yunlong ;Luo Zhicai;Li Hui ;and Zhong Bo
On the basis of wavelet theory, the outlier detection algorithm in satellite gravity gradiometry using wavelet shrinkage denoising is established, and simulation data with white noise and outliers is generated.
The computed and analysis results indicate that wavelet method is a novel outlier detection algorithm with 97% ratio of success.
2010 Vol. 30 (4): 55-58 [Abstract] ( 1820 ) PDF (655 KB)   ( 2990 )
59 SEVERAL PROBLEMS OF STRAIN CALCULATION AND ANALYSIS AND CORRECTION OF RELATED DEVIATION
Yang Guohua ;Wu Yanqiang ;Yang Bo;Zhang Fengshuang; Han Yueping;Zhou Haitao;and Dong Yunhong
There exists many kinds of calculation models of plane and spherical strain fields, but the results are different.It is analyzed the representative models, and points out which model has unbias as well as which one has deviation,which models deviation can be corrected as well as which one can only be used to the strain computing of uniform medium but can not be extended and which model can be
used the calculation and analysis of continuous strain field. Besides, it’s also provides the correction relationship for computing spherical difference movement (displacement) by strain results, and demonstrates the meaning of the nondifferential term in spherical strain model.
2010 Vol. 30 (4): 59-63 [Abstract] ( 1647 ) PDF (764 KB)   ( 3289 )
64 DATA REHANDLING OF CRUSTAL MOVEMENT OBSERVATIONNETWORK FROM 1999 TO 2009
Liu Guangming;Ma Jinhui ;Wu Fumei;and Tang Yingzhe
The meaning and the method of data rehandling of Crustal Movement Observation Network in China are introduced.
From the observations of 1 081 GPS stations in Crustal Movement Observation Network in China from 1999 to 2009 and associated with the data from 47 international IGS core stations, the coordinates and the velocities of 1 081 GPS stations under ITRF2000 and relative to NNRNUVEL1A plate model are obtained.
2010 Vol. 30 (4): 64-67 [Abstract] ( 1850 ) PDF (873 KB)   ( 3221 )
68 InSAR INTERFEROGRAM FILTERING BASED ON SUSAN AND ITS IMPROVED ALGORITHM
Xu Bing;Yin Hongjie;Zhu Jun;and Wang Changcheng
The SUSAN filtering and its improved algorithm are introduced into for InSAR inteferogram filtering.
The effects of the SUSAN and its improved algorithm are compared with that of the Goldstein filter. The experimental results with real data show that the proposed algorithms are superior to Goldstein filter, and make the improvement of 71.7% to 82.6% on Goldstein filter in reducing phase residual. The SUSAN and its improved algorithm, especially the latter,can not only suppress of interference noise better, but also keep the edge information of interferogram.
2010 Vol. 30 (4): 68-73 [Abstract] ( 2262 ) PDF (3019 KB)   ( 3173 )
74 STUDY ON MOBILE CRUSTAL DEFORMATION MONITORING TECHNOLOGY OF CANYON-RESERVOIR
Shang Hong;Liu Tianhai;and Yang Huaining
The technical project of the mobile crustal deformation monitoring in canyonreservoir is studied, and its design ideas are put forth, the layout principles of the monitoring network, and the concrete construction scheme, in order to provide a kind of reference for the comprehensively monitoring the earthquake safety project of the canyonreservoir and the like
2010 Vol. 30 (4): 74-78 [Abstract] ( 1667 ) PDF (645 KB)   ( 4119 )
79 RESEARCH ON BRITTLE-DUCTILE TRANSITION PLANE OF CRUST OF TIBETAN PLATEAU
Yang Qiang;and Dang Yamin;

The crust of the Tibetan plateau and its adjacent area is divided into two layers: the elastic brittle layer and the viscoelastic ductile layer, and then the interior temperature field of the crust by steady heat conductive equation is evaluated.Further, under the condition that fracture intensity is equal to creeping intensity, brittleductile transition plane is obtained by use of Crust2.0 earth model. The results show that brittleductile transition plane locates in middle crust about 20-35 km depth generally. The thicker the crust is, the deeper the transition floor is. Effective viscosity of transition plane located in Tibetan plateau is between

10 19-10 22 Pas, temperature field is between 450-600℃.
2010 Vol. 30 (4): 79-82 [Abstract] ( 1699 ) PDF (973 KB)   ( 3690 )
83 PROGRESS AND PRESENT STATUS OF RESEARCH ON EARTH’S GRAVITATIONAL FIELD MODELS
Zheng Wei;Xu Houze ;Zhong Min ;Yun Meijuan ;Peng Bibo ;and Zhou Xuhua
Firstly, the domestic and overseas Earth’s gravitational field models based on the traditional gravity measurement are looked back since 1966. Secondly, the global gravitational field models established from the data measured by CHAMP are presented. The
results of EIGENCHAMP03S model are only preferably in agreement with those of EIGEN3P model in the longwavelength Earth’s gravitational field, and accord with those of EIGEN1S, EIGEN2 and EIGEN3P models in the mediumlongwavelength Earth’s gravitational field, respectively. Finally, the existing GRACE satellite gravity models are introduced. The accuracy of GGM02S model is almost the same with that of WHIGGGEGM01S due to the similar amount of satellite observations, and the accuracies of all combined models including EIGENCG01C, EIGENCG03C, EIGENGL04S1 and EIGEN5C using combined satellite observations from CHAMP, GRACE, satellite altimetry and surface gravity are higher than those of GRACEonly models including EIGENGRACE01S, EIGENGRACE02S, GGM01S, GGM02S and WHIGGGEGM01S.
2010 Vol. 30 (4): 83-91 [Abstract] ( 2328 ) PDF (752 KB)   ( 4289 )
92 ANALYSIS OF SERVICE PERFORMANCE OF INDIAN REGIONAL NAVIGATION SATELLITE SYSTEM
Feng Laiping ;Zhang Hong ;Jia Xiaolin ; and Wu Xianbing
The structure and characteristics of IRNSS constellation were analyzed.Positioning accuracy is discussed by analysing dilution of accuracy. Based on availability of single point and constellation value, constellation availability is studied when constellation is normal or one of satellites is failure. Results show that the design of IRNSS navigation system is reasonable and it has a good regional coverage. About 10m positioning accuracy can be achieved in India and in the area outside with the extension of 2 000 km. The constellation structure has a certain redundancy as well as good stability.Given a limitation of PDOP 6,at least 95% availability can be achieved when one satellite is failure in these regions.
2010 Vol. 30 (4): 92-97 [Abstract] ( 1723 ) PDF (1549 KB)   ( 3255 )
理论方法研究
98 RE-DERIVATION FOR INFLUENCE OF EARTH’S FLATTING ON TGP
Zhang Hanwei ;Zheng Yong ;and Ma Gaofeng
At present, the development of tidalgenerating potential (TGP) does not take the influence of Earth’s flatting into account.
On the basis of the concept of tidal force,the expression of TGP considering Earth’s flatting by analyzing situations of force at the center of Earth’s mass and using the coordinate transformation, is given.
2010 Vol. 30 (4): 98-101 [Abstract] ( 1768 ) PDF (425 KB)   ( 3630 )
102 ILL MATRIX AND REGULARIZATION METHOD IN SURVEYING DATA PROCESSING
Wu Jie ;Li Mingfeng;and Yu Teng
The explores the illconditioning equation from disturbance, spatial geometry and ellipsoidal structure are explored.
The regularization method which can be better able to abate coefficient matrix of the complex number is given.The numerical test results indicate that the method is better.
2010 Vol. 30 (4): 102-105 [Abstract] ( 1768 ) PDF (359 KB)   ( 4995 )
106 A NEW TEST METHOD BASED ON SPACE VECTOR IN 3D CIRCLE FITTING
Pan Guorong;and Li Huaifeng
A more simple and clear method is put forward to fitting 3D circle. 3D circle could be viewed as great circle intersected by 3D ball and plane, and centre of the 3D circle must be on the vertical plane of two points on the surface of 3D ball; According to space vector, vertical plane could be derived to solute centre with plane, and then radius could be counted inversely.Meanwhile by taking
a real tunnel shield section project as the example, this method is proved to be practical.
2010 Vol. 30 (4): 106-108 [Abstract] ( 1835 ) PDF (369 KB)   ( 3869 )
109 HELMERT TRANSFORMATION OF REFERENCE FRAME
Wei Na;Shi Chuang ;Geng Changjiang;and Liu Jingnan;
Helmert transformation plays an important part in the establishment and maintenance of Terrestrial Reference Frame.
The formulae to realize datum definition using Helmert transformation parameters are rigorously derives. Three kinds of transformation formulae are proved to be equivalent in theory.Taking ITRF2005 for example,the effects of Helmert transformation parameters precision on reference transformation of noncore stations are analyzed, and results show that maximum residual can be up to several centimeters.
2010 Vol. 30 (4): 109-112 [Abstract] ( 1831 ) PDF (446 KB)   ( 3199 )
113 RESEARCH AND ACCURACY ANALYSIS ON REAL TIME KINEMATIC POSITIONING MODEL
Wang Hu ;Wang Jiexian;Bai Guixia;and Li Haojun
Three estimation models of ambiguity in the realtime kinematic positioning are discussed, and a new estimation model of ambiguity is proposed. The parameters of positioning and ambiguities can be separated by using the matrix transform. Only, normal equation of ambiguity is added.On the basis of the characteristics of cycle skip and satellites change, the corresponding method is put forward, it deduces the times of initialization.
2010 Vol. 30 (4): 113-116 [Abstract] ( 1875 ) PDF (693 KB)   ( 3823 )
117 A NEW METHOD FOR ESTABLISHING REGRESSION MODEL
Xu Shuang’an;Yao Yibin;Kong Jian;and Gong Peipei
The regression method is used to study the related but not determined relations between variables, which is widely used in the field of deformation monitoring data processing and analyzing.The method based on classical leastsquares under the indirect adjustment model or on singular value decomposition under the overall leastsquares criterion for solving vegression parameters has some limitations in practical applications,it may weaken the statistical significance of the regression model and the significance test even will fail .A new method is proposed that is to establish the approximate regression equation by the traditional method first,then amendment the regression model by the Total LeastSquares. The feasibility and correctness of the new method are verified by the simulation data and measured
real deformation data and the prediction accuracy can be improved.
2010 Vol. 30 (4): 117-121 [Abstract] ( 1790 ) PDF (424 KB)   ( 2909 )
122 DATA PROCCESSING AND ACCURACY ANALYSIS IN SHIELD POSTURE MEASUREMENT
Chen Suzhen ;Sun Hao ;and Yao Lianbi;
The models and methods for combined treatment of coordinate data and tilt angle are focused on. Coordinate data of control points are obtained from total station. Trim and list are from by tiltmeters. At first, based on largeangle coordinate transformation, the tilt data serves as observed data during the process of adjustment. The next step is to analyze the impact of different accuracies of tiltmeters and different layouts of common points.
The model has been already validated in engineering examples. The result shows that the model can improve the accuracy and reliability of attitude.
2010 Vol. 30 (4): 122-127 [Abstract] ( 1716 ) PDF (400 KB)   ( 2943 )
128 ANALYSIS OF VERTICAL CRUST DEFORMATION BY USINGIMPROVED LEAST-SQUARE COLLOCATION
Chen Guangbao ;Chen Yongqi ; and He Xiufeng
A suitable interpolation of geodetic measurements is relied on in calculation and analysis of recent crustal movements. Leastsquares collocation (LSC) is applied to formulate a continuous velocity fields as a common interpolation method. But LSC requires some priori assumptions about the velocity fields.Therefore we present a improved method that can be used for interpolation of inhomogeneous velocity,in which the traditional leastsquares collocation and the gradient function are combined to extract the trend term of deformation. The method has been tested in two examples. One example is a synthetic data that simulate the geodetic measurements over the area where exists a fault, the other is the vertical deformation rate around Beijing. From the results, stable interpolation can be made in inhomogeneous velocity field, in the same time, the buried fault can well be found.
2010 Vol. 30 (4): 128-132 [Abstract] ( 1825 ) PDF (1002 KB)   ( 3165 )
133 FAST RESOLUTION OF MULTI-SESSION GPS CARRIER PHASE MEASUREMENT BASED ON GRID
Li Changgui ;Lu Zhiping ;Wang Peng;and Li Jian
It is explored how to use grid to fast resolve multisession GPS carrier phase measurement. Firstly, the least squares method is used to derive an adjustment model for the multisession GPS carrier phase measurement, the model quality of being decomposable is analyzed, and it is decomposed into several sub computations. Father the grid workflow formed by these sub computations and the way to realize the workflow are discussed. Finally, a 4session baseline is resolved by using a single computer and a grid, respectively. The experiment results show that the Grid method is feasible and can increase the computing velocity by many times.
2010 Vol. 30 (4): 133-136 [Abstract] ( 1761 ) PDF (494 KB)   ( 2868 )
137 METHOD OF MULTI-KERNEL FUNCTION AND ITS APPLICATION IN GPS TIME SERIES DATA PROCESSING
Yang Bo;Zhang Fengshuang;and Han Yueping
Through testing and studying on the technique of multi-kernel function, which is a new numericalapproximation technique proposed in recent years, it is found that this method has the characteristics as follows:1) It is easy to accomplish the extraction and separation of data of various frequency band during the filtering of GPS time series.2)It is simple and accurate to complete the interpolation when the continuous lack of data is not very badly.3)This method owns analyticity, and the accurate evaluation of parameters and filtering values is rigorous; 4)The computing result is stable, and it is not easy to produce illconditioned matrix.5)The computing is simple and costs short time.
Through some examples of data processing of GPS time series, the suitable multikernel function is recommended, and the problems needing attention are pointed out during concrete applications.
2010 Vol. 30 (4): 137-141 [Abstract] ( 1846 ) PDF (1604 KB)   ( 3142 )
142 IMPROVEMENT OF PHASE UNWRAPPING METHODFOR TWO-DIMENSIONAL CELLULAR AUTOMATA
Yan Man;Liu Guolin ;Hao Huadong ;and Tao Qiuxiang
An improved phase unwrapping method for cellular automata is proposed. It revises the four neighborhood of the original method to the nearest neighborhood, begins from the boundary of the interferogram to iterate, eliminates the phase fringes one by one to achieve the purpose of phase unwrapping.The experiments by using the simulated and real interferograms are made. The result shows that this method can decrease the original iterative times, reduce the occupancy rate of the memory and improve the accuracy of the phase unwrapping.
2010 Vol. 30 (4): 142-145 [Abstract] ( 1906 ) PDF (1735 KB)   ( 2844 )
146 EXPLORATION OF LARGE-SCALE REFERENCE STATIONNETWORKING AND ZONING SERVICE
Gu Shengfeng;Hu Yuzhong;and Tang Weiming
The approach that by sharing part of the base stations between adjacent subCORS to eliminate the “service gap” is discussed. In order to achieve largescale subCORS data broadcasting services, it is required to carry out subCORS subnetting.
We take the advantage of the FCM algorithm to obtain the membership degree of each triangle to each partition and use the triple tree to describe the topology for each partition.The result shows that by use of these methods the close and continuous subnetting with the number of baseline slightly lower than the threshold for each subnet can be obtained.
2010 Vol. 30 (4): 146-150 [Abstract] ( 1764 ) PDF (963 KB)   ( 3280 )
151 INFLUENCE OF MISJUDGMENT FOR DOUBLE DIFFERENCE AMBIGUITIES BETWEEN REFERENCE STATIONS ON VRS OBSERVATIONS
Zhang Feng and Hao Jinming
Virtual reference station technique is usually used to compute approximate corrections to the true errors of rover’s position through interpolated algorithms,thus it can achieve the positioning accuracy of centimeterlevel,but ambiguity errors between reference stations is amplified in creating corrections of baselines between reference stations. The influence of double difference errors on VRS observations is different for using different interpolation algorithms. Through the comparison between a linear plane and higher order surface represented by a quadratic function, the conclusion can be drawn that the linear plane interpolation algorithm is fit for creating VRS corrections. Because it can weaken the influence of errors between reference stations on VRS observations, and the impact of network configuration is on the small side.
2010 Vol. 30 (4): 151-155 [Abstract] ( 1670 ) PDF (493 KB)   ( 2912 )
156 STUDY ON PHASE UNWRAPPING OF SAR INTERFEROGRAM OVER MOUNTAIN REGION IN WESTERN CHINA
Ju Chengyu;Deng Kazhong;and Fan Hongdong;
The SNR of part of interferogram over the complex topography in the western China is low, it makes unwrap of wrapped phase difficult. The interferograms over the mountain region in the western China with 9 methods based on pathfollowing, least square and networkflow were unwrapped. The experiment and analysis show that the method of minimum cost flow in irregular network is optimal for unwrapping the SAR interferogram over the western China.
2010 Vol. 30 (4): 156-159 [Abstract] ( 1720 ) PDF (1049 KB)   ( 3202 )
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