jgg

大地测量与地球动力学

	Home \| About Journal \| Editorial Board \| Submission Guidelines \| \| Open Access Statement \| \| Contact Us \| 中文

Submission Online

Manuscript
Tracking

Editorial Office

Editor-in-Chief

Online befor
Printed

Search

Current Issue

	2012 Vol.32 Issue.5 Published 2012-11-29

地壳形变与地震

	1	INVERSION OF NON-HOMOGENEOUS NEGATIVE DISLOCATION FOR LONG LEVELING SECTION AT MIDDLE-EASTERN SEGMENTS OF WEIHE FAULT
		Zhang Xi; Zhang Sixin; Li Ruisha; Tang Hongtao;and Jia Peng
		Using vertical deformation data of longleveling section in recent years at the eastern Guanzhong in Shaanxi province, by the aid of construction and inversion with nonhomogeneous negative dislocation model with stratification changes of dislocation and dip angle, the geometry parameters of the middleeastern segments of Weihe fault are computed. The dynamic evolution of strain energy accumulation and difference between different depths together with the relation to energy release and adjustment influence of the Wenchuan earthquake are studied. The results show as follows: 1)The fault is listric nearly to right angle from earth surface to shallow layer, and the depth is basically consistent with geological data. 2) The strain accumulation is mainly located at uppermiddle layers, displaying obviously before the Wenchuan earthquake, decreased during 2008-2009 probably related to energy release, with reverse related to adjustment after this earthquake during 2009-2010(possibly promoted the Gaoling 4.4 earthquake); up to 2011, this adjustment situation had not ended completely.
		2012 Vol. 32 (5): 1-5 [Abstract] ( 1493 ) PDF (1218 KB) ( 2697 )

	6	GRAVITY INVERSION OF DEEP INTERFACES IN THREE GORGES DAM REGION
		Wang Jian;Shen Chongyang;Li Hui;Xiao Fan;and Liu Xiaoling
		The Parker-Oldenburg iterative inversion method with constant density and variable density model was applied to the Three Gorges dam region. Comparing and analyzing the reversed results with the two models, we can obtain of the accurance undulation the upper, middle and lower crust interfaces(B3,B2,B1). The results indicated that the variable density model’s reverse results is more reliable，the general morphological characteristics of two reverse results are consistent. Between the differences of the inversion results, change of B2 is the most, the maximum difference reaches 4 km; the thickness of the middle crust in the Three Gorges dam is about 9 km which is the thinnest area in the Three Gorges region.
		2012 Vol. 32 (5): 6-11 [Abstract] ( 1425 ) PDF (2228 KB) ( 2685 )

	12	OPTICAL DATING OF SUNJIALOU TRENCH IN TANGSHAN AND ITS SIGNIFICANCE FOR PALAEOSEISMIC EVENTS
		Zhao Junxiang;Jiang Wali ;Guo Hui ;and Yu Shen’e
		We use simplified multiple aliquot regenerativedose(SMAR) protocol from fine grain quartz(4～11μm) to systematically date samples from Sunjialou trench across Tangshan earthquake zone in 1976. OSL signals of these samples dominated by fast component show that they are suitable for OSL dating. On the basis of the optical ages and the burial depth of samples, the agedepth curve and function of the trench are obtained. Through it we inferred depositional rate. The results suggest that depositional rate curves on both sides of the fault show two parallels between 50 and 7.16 ka, which indicates sedimentary environment are stable and no tectonic movement happened during that time interval. The depositional rate is about 0.03 m/ka and 0.6 meters distance in the range of two parallels is vertical offsets generated by the 1976 Tangshan earthquake. Activity caused by the main fault in about 50 ka leads to depositional rate increase, which is 0.1 m/ka. Coeval activity in the secondary faults causes depositional rate in western segment about twice that of eastern segment, which is 0.2 m/ka. In conclusion, tectonic movement is main factor for depositional rate change in study area but climate change. The depositional rate change may be useful approaches for the palaeoseismic events.
		2012 Vol. 32 (5): 12-16 [Abstract] ( 1522 ) PDF (1427 KB) ( 2463 )

	17	ON CHARACTERISTICS OF HYPOCENTER DISTRIBUTION AND RUPTURE COMPLEXITY OF WENCHUAN AFTERSHOCK SEQUENCE ALONG LONGMENSHAN FAULT ZONE NORTH TO BEICHUAN
		Lü Jian ;Wang Xiaoshan ;Miao Chunlan ;Su Jinrong ;and Jin Yuke
		On the basis of precise locations of the Wenchuan earthquake sequence by using the HYPODD method, the focal mechanisms of the aftershocks (M5.0) occurred on the Longmenshan fault zone north to Beichuan were inversed by using the CAP method and the characteristics of hypocenter distribution and rupture complexity of strong aftershocks are discussed. The results are that the focal depth of Wenchuan aftershock sequence decreased gradually from Yingxiu of Wenchuan to Nanba of Pingwu along Longmen Shan fault zone, which beyond the segment boundary located in Beichuan, and the epicenters were distributed along the YingxiuBeichuanNanba coseismic surface rupture zone in the Central Fault. The aftershock sequence was characterized as less secondary segmented activity in Central Fault Zone north to Beichuan. The aftershocks (M≥5.5) were occurred on the end, transition or dislocation of the aftershocks zone. According to the focal mechanism, four of the seven stronger aftershocks are thrust and the others are strikeslip, it may suggest that the process of the aftershock activity was related to the BeichuanQingchuan Fault, PingwuQingchuan Fault etc.
		2012 Vol. 32 (5): 17-21 [Abstract] ( 1712 ) PDF (1935 KB) ( 2537 )

	22	APLICATION OF CORS OF GNSS IN LAND SUBSIDENCE MONITORING IN TIANJIN
		Gao Yanlong;Zheng Zhijiang;Han Yueping;Fu Lming;and Chen Fuchao
		The difficulties and uncertainties caused by reference datum changes in land subsidence estimation are discussed. In order to solve the difficulty,the method in which the velocity datum is determined by the observed elevation variations time series combined with the repeated leveling data at several GNSS stations is presented. Some practical examples are given for the comparison between this method and the traditional one,it is proved that the new method has some advantages.On the basis of these results, some recommendations about the land subsidence monitoring and the evaluation method in the Tianjin area are proposed. These recommendations may have some helps for land subsidence monitoring and evaluation in other similar areas.
		2012 Vol. 32 (5): 22-26 [Abstract] ( 1665 ) PDF (1628 KB) ( 2855 )

	27	MICRO-DYNAMIC CHARACTERISTICS OF GPS SITES IN TIANJIN AREA
		Ta La;Guo Liangqian;Liu Xia;and Chen Juzhong
		On the basis of the continuous displacement parameters of each site and the overall strain rate parameters of the Tianjin area obtained from the observational data of Tianjin GPS local network, the microdynamic displacement of each site and the microdynamic crustal strain rate of the Tianjin area as a whole were studied. The results show that in the first half of 2006 and whole 2008, there was a substantial change in the majority of the sites, which shows that the activity in the crust enhanced in this period. The sites displacement value in the first half of 2006 were the maximum during the period 2004-2010, and crustal strain rate of Tianjin in MarchApril 2006 also reached the maximum. The compressive strain axis significantly deviated from the normal direction of the area(normal NEE ).On July 4,2006 , Wenan Ms5.1 earthquake was occurred near the southwest of Tianjin. The displacements of part sites of the Tianjin area relatively increased in 2008, which may be affected by the farfield deformation of the Wenchuan Ms8.0 earthquake.
		2012 Vol. 32 (5): 27-32 [Abstract] ( 1705 ) PDF (2557 KB) ( 2471 )

	33	ESTABLISHING REGIONAL CRUSTAL MOVEMENT VELOCITY FIELDWITH COLLOCATION MODEL BASED ON DISPLACEMENT PRINCIPLE
		Li Chong ;Li Jiancheng ;and Qu Wei
		For the research on regional crustal movement, collocation model is always used to estimate the points which need attention without observation.However,because of its tendency characteristics of function model and its active characteristics of statistic model, accurate covariance matrix of the model is hard to be determined.This paper has analyzed and compared some popular covariance function, then brought up a new collocation model based on displacement principle. The new model can build up different collocation model aiming at different points, thus many avoid the accuracy loss of using experiential covariance function. The accuracy of the new model is apparently higher than normal collocation model through special verification.
		2012 Vol. 32 (5): 33-36 [Abstract] ( 1570 ) PDF (766 KB) ( 2331 )

	37	DETERMINATION OF SURFACE RUPTURE CHARACTERISTICS OF WENCHUAN EARTHQUAKE AT DUJIANGYAN SEGMENT BASED ON ELEVATION CONTROLLING POINTS AND ENGINEERING DAMAGE
		Ren Junjie;Sun Xinze ;Ding Rui ;and Gong Zheng
		The distribution of surface rupture of Wenchuan earthquake at Dujiangyan segment remains controversial for lack of direct geological evidence. We use newcollected GPS survey controlling points at the Dujiangyan reservoir and postseismic resurveyed cadastral data and combine some engineering damages in the studied area to obtain coseismic vertical displacements. The results demonstrate that the Dujiangyan surface rupture segment consists of three branches: the Yingxiu part has a clear geomorphological feature with a vertical displacement of 1.5-2 m; the Longchi part ruptured the Longchi and Longxi tunnels with a vertical displacement of about 0.8 m, the Zipingpu part passed through the Zipingpu reservoir with a uplift of 0.7 m. Finally, the three rupture parts merge into one eastward segment at Hongkou town and collectively comprise the initial rupture fault segment. In addition, regional uplift is smaller than coseismic vertical displacements along the ruptured faults, suggestive of an abrupt increase at the fault zone.
		2012 Vol. 32 (5): 37-40 [Abstract] ( 1658 ) PDF (1362 KB) ( 2694 )

	41	STUDY ON TECTONIC DEFORMATION AND QUATENARY ACTIVITY OF MIDDLE SEGMENT OF BAIHE-GUCHENG FAULT BELT
		Lei Dongning;Cai Yongjian;Qiao Yueqiang;Yu Song;Wu Jianchao;and Miao Weidong;
		Through field survey, with geological and geomorpohologic methods and dating the fault gouge and Quaternary sediments, we made certain study on tectonic deformation and activity of the middle segment of BaiheGucheng fault. Some conclusions can be drawn that the fault belt suffered from multistage tectonic deformation and it is clearly zoning. The lifting velocity of fault and its neighbouring area ranges from 0.64 mma -1 to 0.85 mma-1 since the Middle stage of Late Pleistocene. The fault was predominantly active in the Early Quaternary with sinistral slip component. The seismicity of fault and nearby tends to enhance in time domain and is tectonically relatated to the fault in spatial domain.
		2012 Vol. 32 (5): 41-47 [Abstract] ( 1505 ) PDF (2487 KB) ( 2685 )

理论方法研究

	48	RESEARCH ON PROPERTIES OF TOTAL LEAST SQUARES ESTIMATION
		Wang Leyang;
		Through theory derivation and proof, some properties of the total least squares estimation are found. The total least squares estimation is the linear transformation of the least squares estimation. When the coefficient matrix contains error,the least squares is biased.The total least squares estimation is unbiased. The condition number of the total least squares estimation is bigger than that of the least squares estimation, so the total least squares estimation is more easier to be affected by the data error than the least squares estimation. Through further derivation, the relation of solutions, residuals, unit weight variance estimations between the total least squares and the least squares are given.
		2012 Vol. 32 (5): 48-52 [Abstract] ( 1545 ) PDF (493 KB) ( 2576 )

	53	PREDICTION OF DYNAMIC DEFORMATION BASED ON CHAOTIC IMMUNE OPTIMIZATION ALGORITHM BRF NEURAL NETWORK
		Zhu Yu;Zhao Qing;and Mei Yan
		Aiming to the shortcoming of the traditional prediction model, a method for designing the RBF neural network based on chaotic immune optimization algorithm (CIOA) is proposed, which uses CIOA to the RBF network center vector and weights optimization. By applying chaos mutation operator to producing new antibody and applying immune selection operator to realizing the survival of the fittest, CIOA is able to maintain a good diversity. At the same time, CIOA has higher convergence speed and it can effectively avoid falling into local optima. The results show that chaotic immune optimization RBF neural network applied to the prediction of dynamic deformation, effectively improve the predicted speed and performance.
		2012 Vol. 32 (5): 53-57 [Abstract] ( 1511 ) PDF (768 KB) ( 2690 )

	58	DETERMINATION OF MEAN SEA LEVEL GEOTENTIAL FROM GLOBAL GRAVITY FIELD MODEL AND GLOBAL SEA SURFACE HEIGHT MODEL
		Chu Yonghai;and Li Jiancheng;
		The geoidal geopotential W0 was determined on the basis of global gravity model (EGM2008 and EGM96) and global mean sea surface height model (CLS01, DNSC08, WHU2009 and CNES_CLS10). If the sea surface topography correction was applied to the surface height, the geoidal geopotential values 62 636 858.333 3 m ² s ^-2 and 62 636 858.260 6 m ² s ^-2 were derived with a difference less than 1.40 m ² s ^-2 compared to the normal level ellipsoid geopotential within free tide and mean tide system respectively. The mean sea surface topography computed based on this W0 shows that the results are reliable.
		2012 Vol. 32 (5): 58-62 [Abstract] ( 1698 ) PDF (861 KB) ( 2767 )

	63	PROCESSING AND ANALYSIS OF TIDAL DATA FORZHONGSHAN STATION,EAST ANTARCTICA
		Huang Jifeng;E Dongchen;Zhang Shengkai;and Zhou Chunxia;
		A permanent tidal station was constructed at the Chinese Zhongshan station in Feb. 2010. We calculate the results of leveling survey for the tidal datum system and the calibration of the tide gauge zero. The harmonic constants of 170 tidal constituents are obtained and the tide table for Zhongshan station is compiled.
		2012 Vol. 32 (5): 63-67 [Abstract] ( 1507 ) PDF (985 KB) ( 2895 )

	68	ANALYSIS OF ACCURACY AND APPLICABILITY OF TRANSFORMATION BETWEEN 1954 BEIJING COORDINATE SYSTEMAND 1980 XI’AN COORDINATE SYSTEM
		Wang Wenli;Cheng Chuanlu;Li Dong;Chen Junying;and Jiang Guangwei
		Employing the coincidence point between referenceellipsoidcentric coordinate system and the CGCS2000 which are proportional distributed,of hight accuracy and wellcurrency,using the Bursa model to transform the coordinate and from the transformation residuals, the coordinate’s plane accuracy of the 1954 Beijing Coordinate system and the 1980 Xi’an coordinate system are analyzed, objectively evaluate the applicability and put forward some reasional suggestion about the continuance or suspense of asing the 1954 Beijing coordinate system and the 1980 Xi’an coordinate system.
		2012 Vol. 32 (5): 68-71 [Abstract] ( 1578 ) PDF (1254 KB) ( 2765 )

	72	RESEARCH ON LONG BASELINE AMBIGUITY RESOLUTION OF NETWORK RTK
		Ke Fuyang ;Wang Qing ;and Pan Shuguo
		With the distance between reference stations longer and longer, the atmospheric error related to spatial distance will be significantly reduced and can not be separated from ambiguity, so that the ambiguity is difficult to be fixed accurately. In view of this, an ambiguity resolution method suitable for long baseline is advanced based on partial ambiguity and Kalman filter. Firstly, the ambiguity of the satellites with higher elevation are resolved by twosteps and partial ambiguity methods. Secondly, the zenith atmospheric delay errors of reference stations are estimated by Kalman filter. Finally, the ambiguity of satellite with lower elevation between long baseline reference stations is corrected by the zenith atmospheric dalay errors estimated for the accurate resolution. At the last, the method is verified by the observations of part referece stations in Jiangsu CORS, the results show that the double difference ambiguity is accurate and reliable for the satellites with lower elevation between long baseline reference stations.
		2012 Vol. 32 (5): 72-77 [Abstract] ( 1763 ) PDF (1073 KB) ( 2859 )

	78	STUDY ON TRANSFORMATION FROM CARTESIAN TO GEODETIC COORDINATES
		Shi Haifeng;and Zhang Weibin
		As the Bowring direct algorithm limited to the impact of geodetic height, when the H is of more than 1 000 km the error with direct algorithm will increase. In order to solve the problem,this paper presents a new algorithm which considers the direct solution as an initial value of the iterative algorithm. The result shows that the new algorithm is sufficiently precise and stable,simultaneously, no longer limited to the impact of geodetic height.
		2012 Vol. 32 (5): 78-81 [Abstract] ( 1545 ) PDF (1037 KB) ( 3263 )

	82	INERTIAL/GEOMAGNETIC INTEGRATED NAVIGATION ALGORITHM BASED IMM-PF
		Liu Ming;and Wang Haijun
		The problem of nonlinearity and system noise uncertainty in the inertial and geomagnetic integrated navigation systems seriously affected the navigation accuracy of the systems.For solving the problem, Firstly, nonlinear model set of the system is established aming the system noise uncertainty, and the model set should cover a variety of noise conditions. Secondly, the Particle Filter (PF) is used as the IMM matched filter. Thus IMMPF algorithm is proposed, and the nonlinear equations can be used directly in this algorithm. The simulation results show that, compared to conventional EKF algorithm, in the condition of system noise uncertainty, IMMPF algorithm can automatically adjust the system model, can guarantee the convergence of the system quickly, and can improve the navigation accuracy.
		2012 Vol. 32 (5): 82-85 [Abstract] ( 1540 ) PDF (676 KB) ( 2530 )

	86	RESEARCH ON BURSA NONLINEAR 7-PARAMETER TRANSFORMATION WITH PSO ALGORITHM
		Yang Xing;Zhu Dadong;Zhao Gang;and Li Zhiqing
		The 7parameter is the main parameter for space coordinate transformation,and the minor error of 7parameter could lead to large coordinate conversion deviances.In order to improve the computational accuracy of 7parameter,a mathematical model of Bursa 7parameter analysis based on the partical swarm optimization(PSO) algorithm was established.Compared with a least square method,the model can avoid effectively the matrix’s morbidity problem,difficulty of selecting initial values,the convergence of algorithm.Finally,the practical application shows that the model has many advantages such as high accuracy and can be adapted large rotation angle.
		2012 Vol. 32 (5): 86-90 [Abstract] ( 1494 ) PDF (588 KB) ( 2337 )

	91	SEA LEVEL ANOMALY FORECASTING BASED ON COMBINED MODEL OF LEAST SQUARE AND ARMA
		Sun Wen;and Wang Qingbin
		A method based on the least square (LS) model combined with the ARMA model is used to predict the sea level anomaly (SLA), where the periodic terms and linear trends are fitted using LS while the stochastic terms are predicted with ARMA model. A test was carried out in the North Pacific Ocean by using satellite altimetry data and the results show that the accuracy for 1 year and 2 years’ prediction are 0.29 cm and 0.63 cm, respectively. It indicates that this combined model can be used for the short term SLA prediction in sub-centimeter accuracy.
		2012 Vol. 32 (5): 91-94 [Abstract] ( 1518 ) PDF (669 KB) ( 2511 )

	95	BATHYMETRY PREDICTION FROM VERTICALGRAVITY GRADIENT ANOMALIES
		Hu Minzhang ;Li Jiancheng;and Li Dawei
		The response function between seafloor undulation and sea surface vertical gravity gradient anomalies is derived based on the response function between sea floor velief and sea surface gravity anomaly. Accordingly, a simulation research is carried out with Gaussian seamount model.The effects of lithosphere effective elastic thickness,crustal density and the truncation wavelength on predicted results are studied. Finally,a high accuracy bathymetry model was established from actual vertical gravity gradient anomalies data.
		2012 Vol. 32 (5): 95-98 [Abstract] ( 1677 ) PDF (1154 KB) ( 3054 )

	99	OPTIMAL METHOD FOR GM(1,1) MODELING FOR PREDICTION OF DEFORMATION TAKING COMPENSATION FOR MODEL ERRORS INTO ACOUNT
		Gao Ning;Cui Ximin ;and Gao Caiyun
		By analyzing the main error source in the GM(1,1) modeling,the GM(1,1) model taking the compensation for model error was proposed and then,through an example,compared the model(with compensation for error) with the results predicted with conventional models GM(1,1),PGM(1,1) and timevarying GM(1,1).The results show that the prediction accuracy with the model GM(1,1) of error compensation is the highest.
		2012 Vol. 32 (5): 99-102 [Abstract] ( 1490 ) PDF (670 KB) ( 2630 )

	103	ESTABLISHMENT OF HARMONIC ANALYSIS MODELS OFSINGLE COMPONENT AND COMPOSITE COMPONENTSOF DISTURBED GRAVITY GRADIENT TENSOR
		Liu Xiaogang;Zhang Liping ;Wang Jun ;and Pu Tingting
		The harmonic analysis model of single component Tzz and composite components Txx+Tyy,Tzz-Txx-Tyy of disturbed gravity gradient tensor to compute the Earth’s gravitational field model(EGM) are deduced. The influences of disturbed gravity gradient data in different resolutions and with different errors on the accuracy of EGM are analyzed.Thus, the models established here are validated with simulated data. Results show that the harmonic analysis method could not recover the EGM completely because of the influence of continuation and gridding errors as well as the indetermination of smoothness factor. The effective degree and accuracy of EGM are gradually falling along with the increase of errors. The accuracy of EGM computed by composite components Tzz-Txx-Tyy is the highest while that of the composite components Txx+Tyy is the lowest.
		2012 Vol. 32 (5): 103-107 [Abstract] ( 1744 ) PDF (2439 KB) ( 2302 )

	108	EFFECT OF OCEAN TIDE LOADING ON GPS PRECISE POSITIONING BASED ON DIFFERENT OCEAN TIDE MODELS
		Zhao Hong;Zhang Qin;Huang Guanwen;and Tu Rui
		In order to study the regular effect of ocean tide loading on GPS positioning in different regions, this paper deduces and analyzes the effect formula of ocean tide loading on GPS stations positioning.On this basis, through example of the GPS stations in Jiangsu and Xi’an, the NAO99b and FES2004 ocean tide model which are inversed with T/P altimetry data, are synthetically adopted to calculate the effect of ocean tide loading on GPS positioning and baselines. The results show that the magnitude of the effect on GPS positioning of offshore stations is up to centimeter, which is 4-5 times as large as that of inland stations. And the effect of ocean tide loading on U direction is much larger than E,N directions and the effect difference on GPS baselines in different areas is less than 1 cm. From the comparison of NAO99b and FES2004 ocean models we know the effect of the two models have little difference in the inland, but on the coast the difference is large, which is 1 cm or more.
		2012 Vol. 32 (5): 108-112 [Abstract] ( 1699 ) PDF (1347 KB) ( 2739 )

	113	RESEARCH ON ANALYSIS METHOD OF BACKGROUND NOISE OF CONTINOUS GRAVITY STATIONS BASED ON HHT
		Zhou Lijuan;Li Hui;Yang Guangliang;and Ma Weiyu
		This paper introduces a new method based on HHT algorithm to analyze background noise , which is better than Wavelet transform proved by experiments. Besides, this paper studies how to apply the method to background noise analysis of continuous gravity stations and analyzes background noise of the cave stations with same top cover thickness and geological tectonic conditions with the method, as a result, characteristics of background noise is obtained.
		2012 Vol. 32 (5): 113-117 [Abstract] ( 1792 ) PDF (2207 KB) ( 2410 )

	118	ANALYSIS OF EFFICIENCY OF APPLYING MKL AND OPENMP POLYNUCLEAR PARALLEL ALGORITHMS TO RECOVERY OF HIGH DEGREE EARTH’S GRAVITY FIELD
		Chen Qiujie ;Shen Yunzhong ;and Zhang Xingfu
		The ordinary matrix operation algorithms are difficult to meet the needs of high degree gravity field recovery. In order to improve computational efficiency, this article applied OpenMP parallel computing libraries and MKL scientific computing libraries to high degree earth’s gravity field recovery, which significantly improved the computational efficiency. Simulation results are as follows. 1)When making up of sub normal equation coefficient matrix with a single epoch as the solver unit, OpenMP algorithm can store normal equation coefficient matrix under the compressed triangle and OpenMP algorithm’s overhead of memory and time are relatively acceptable.2)When the author makes up of the high dimension’s coefficient matrix with more than one epoch, and then forms the normal equation,MKL algorithm can make an efficient performance.3)The efficiency of MKL inversion algorithm is much higher than OpenMP algorithm.4)Utilization of the advantages of OpenMP and MKL algorithms can significantly improve the efficiency of high degree earth’s gravity field recovery.
		2012 Vol. 32 (5): 118-123 [Abstract] ( 1716 ) PDF (787 KB) ( 3329 )

	124	PREDICTION OF PEAK IONOSPHERIC TOTAL ELECTRON CONTENT OF EQUATORIAL IONIZATION ANOMALY BASED ON PARTIAL LEAST SQUARE REGRESSION
		Xu Zhenzhong;Wang Weimin ;and Deng Liang
		On the basis of the 1999—2009 IONEX format total electron content (TEC) data over 120°E from IGS, the method of Partial Least Square Regression is used to establish the prediction model of EIA(equatorial ionization anomaly) index. The TEC data from 1999 to 2008 were used to fit the prediction model and the allyear TEC data of 2009 was used to test the model. The results of the forecasting experimentations of the model show that this model can accurately describe the variation of EIA index Inc (TEC of north crest) and Isc (TEC of south crest), but the prediction effect of Inc is better than the Isc. The mean absolute error of Isc and Inc is about 4.4410TECU and 2.915 1 TECU, the mean relative error of Isc and Inc is about 23.26% and 10.78%. The correlation coefficient between the actual values and predicted values of Isc and Inc is 0.712 2 and 0.785 9 respectively.
		2012 Vol. 32 (5): 124-127 [Abstract] ( 1450 ) PDF (894 KB) ( 2328 )

	128	SLOPE IMPROVED MORPHOLOGICAL FILTERING ALGORITHM FOR LIDAR POINT CLOUDS
		Li Feng;Cui Ximin;Yuan Debao;Wang Guo;and Zhang Ling;
		In order to solve the problems on overmuch predefine parameters prior to performing classical morphological filter, this paper proposes an improved slope morphological filter algorithm. Firstly, an average approximate slope of the whole data sets is automatically calculated, and then the height difference threshold used in window iteration is estimated. Furthermore, the sorts of several point clouds in a grid are identified according to a slope of a grid and height difference threshold. As a result, terrain points are retained and nonterrain points are removed. The experimental results show that this approach is able to remove majority offground points effectively and reduce type Ⅰ errors along with total errors by means of inputting a maximum building size and errors of LiDAR.
		2012 Vol. 32 (5): 128-132 [Abstract] ( 1439 ) PDF (960 KB) ( 3395 )

	133	A NEW METHOD BASED ON MATRIX TRANSFORMATION ALGORITHM FOR LONG BASELINE MULTIFREQUENCY RAPID AMBIGUITY RESOLUTION
		Huang Lingyong ;Song Lijie ;Wang Yan ;and Zhi Suiqiang
		The matrix transformation algorithm for ambiguity resolution is transformation introduced，and the matrix changing algorithm for long baseline multifrequency rapid ambiguity resolution has been principally analyzed. The narrowlane combination ambiguity resolution in long baseline transformation matrix can not be realized in a single epoch, the data smoothing method has been used to solve this problem. Finally Beidou triplefrequency data have been used to validate the algorithm, the result indicates the matrix transformation algorithm can realize long baseline multifrequency rapid ambiguity resolution, and enhance the efficiency of long baseline precise positioning and navigation.
		2012 Vol. 32 (5): 133-136 [Abstract] ( 1428 ) PDF (881 KB) ( 2318 )

	137	ANALYSIS OF NON-LINEAR DRIFT OF SPRING GRAVIMETER
		Wei Jin;Liu Gaochuan ;Li Hui;Shen Chongyang; and Yao Yao;
		More than 3 years gravity data recorded at Guza seismostation using DZW gravimeter are analyzed along with ground water, precipitation and two global continental water storage models (GLDAS, CPC). It is shown that the linear drift of the instrument is about 1 200×10 ^-8 ms^-2 /a stablely. Furthermore, after artificial disturbance (such as power interrupt, restart, lightning), the instrument drift is inconsistent with the previous, so called nonlinear drift that is different from linear drift. Corrected with polynomial fitting method considering the barth tide, air pressure and polar tides, the gravity residual is ±(10-15)×10 ^-8 ms^-2 and shows 4 gravity anomalous variations synchronous with the precipitation for 3 years.So, this research indicates that the drift rule of spring gravity for long time and supply a new method for correcting drift and obstaining gravity variations affected by water loading.
		2012 Vol. 32 (5): 137-142 [Abstract] ( 1566 ) PDF (1297 KB) ( 2770 )

观测技术

	143	AN EXPERIMENTAL STUDY ON FLEXIBLE OBSERVATION PIERS OF GNSS
		Wu Peizhi;Xu Ping;Zhao Guiru ;Xing Chengqi;Zhang Zhongwu;Xu Bin;Bai Yongfu;Hu Leyin;and Yin Jiyao
		On the basis of the requirement of the observation piers to have the ability to work for the GNSS continuous observation in the nonearthquake period and to reduce the recordable ground displacement threshold in the earthquake period, we designed and built 3 flexible GNSS observation piers with the dual drum sinkingmode at Dongsanqi station. With these three flexible observation piers, we carried out the continuous observation several months in the same environment and the same time period. Through examining the results which solved in the same conditions, we have found that the flexible GNSS observation piers with the dual drum sinkingmode are able to be used in the continuous observations. At the same time, the shock and pulse experiments results shown that the inverted pendulum type observation piers for testing have the amplification ability. The amplification ability of this type of piers proved the possibility to reduce the recordable ground displacement threshold. Considering that there were no earthquakes more than \%M\%3.0 in the testing area in the testing period, some more detailed study will be took out in the future.
		2012 Vol. 32 (5): 143-147 [Abstract] ( 1629 ) PDF (1836 KB) ( 2574 )

	148	ANALYSIS OF ACCELEROMETER PERFORMANCE PARAMETERS FOR SATELLITE GRAVITY GRADIOMETRY
		Zhu Zhu ; and Zhou Zebing;
		Spaceborne gravity gradiometer is a core sensor in satellite gradiometry, and accelerometer is the basic unit of gravity gradiometer, whose performance directly affects the level of gravity field recovery and space resolution. Combined the basic operation principle with the real L1b data of the satellite gradiometry mission GOCE, the effects of the resolution, scale factor and quadratic factor of accelerometers are specified in this paper. On the basis of analysis results,finally,we propose that the higher sensitive accelerometers and threeaxis dragfree control technologies should be developed and applied into the future satellite gradiometry mission.
		2012 Vol. 32 (5): 148-153 [Abstract] ( 1385 ) PDF (1437 KB) ( 2529 )

	154	DESIGN OF ELECTROSTATIC SUSPENSION ACCELEROMETER BASED ON EIGHT PAIRS OF DIFFERENTIAL CAPACITANCE ELECTRODES
		Hu Ming;Bai Yanzheng ;Zhu Zhu ;Wu Shuchao ;and Zhou Zebing;
		The capacitance sensing and feedback control combination algorithm for redundant design based on eightpair capacitance electrodes, which is employed to the electrostatic suspension accelerometers in the GOCE gravity gradient satellite, is discussed, and then the preproposal on failure recovery for some possible faults of an accelerometer in orbit is formulated.Finally, its improvement reliability compared to similar accelerometers but with sixpair electrodes for the CHAMP and the GRACE missions is presented.
		2012 Vol. 32 (5): 154-159 [Abstract] ( 1819 ) PDF (1015 KB) ( 2657 )

·

·

·

·

·

·

More...

·

·

·

·

·

·

More...

Copyright © 2013 Editorial office of jgg
Supported by: Beijing Magtech