GNSS World of China

2018 Vol. 43, No. 1

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  Precision Analysis of the BDS GEO/IGSO/MEO Observables and Stochastic Model Refining
LIU Yongjian, JIANG Yong
2018, 43(1): 1-6. doi: 10.13442/j.gnss.1008-9268.2018.01.001
Abstract:
With 10-days observation data of CUT0 station in MGEX observation network, we calculate the single-difference residuals sequence using the method of the zerobaseline single-difference model, and then deducethe noise of GEO/IGSO/MEO observables. The refined elevation stochastic model is established by the leastsquare method through the statisticsof observation noise with the changing of elevation. The results show that:there is slight difference in different kind satellite of BDS about observation precision, and the precision from high to low isMEO, IGSO, GEO; the observation precision of phase is about 129 times higher than pseudorangein B1, and it’s about 118 times in B2; the accuracy of BDS observation is slightly better than GPS. Further, the baseline test results indicate that the refined stochastic model can improvethe accuracy in epoch-by-epoch kinematic positioning. The average point accuracyis increased by 42.1%,and RMS values are increased by15.3%, 31.6%, 31.4% in E, N, U direction respectively.
A Method of GNSS Pseudorange Multiple Outlier Prior Detection Based on Observations Domain
WU Fengbo, SONG Ge
2018, 43(1): 7-14. doi: 1008-9268(2018)01-0007-08
Abstract:
It is difficult to distinguish gross error observations when conducting GNSS multiple outlier detection using a statistical hypothesis test method based on least squares.To solve theproblem, a new priordetecting method is proposed in this paper.The detecting measures are gaussian distribution and independent to each other.Thus multiple gross errors can be simultaneous exactly located by testing normality of the detecting measures. An experiment on the method is conducted with IGS data. Results are as follows:First, the detecting measures conform to normal distribution confirmed its good outlier detectable characteristics;Second,the multiple outlier detecting results showed over 92% detection rate of this method;Atlast,theSPP results influenced by multiple gross errorswere significantly improved byreducing the weights of identified error observables.
  Discussion on Plane Coordinate Transformation Basedon Barycentre Datum
YU Guorong, FENG Guoxin, ZHANG Jian
2018, 43(1): 15-18. doi: 10.13442/j.gnss.1008-9268.2018.01.003
Abstract:
Datum unification and coordinates transformation are always one of the key problem in surveying engineering project. In this paper, the results show that the barycentric coordinates method adopted to overcome the strong correlation problem between the parameters in coordinates transformation model, are basically the same as the four- parameter method. This method simplifies the calculation and enhances the reliability of numerical calculations. Due to the extensive application of modern computing devices, the difference between the two methods is not obvious. The reliability of various coordinate transformation algorithms depends heavily on the accuracy and the distribution of known points. In polar coordinates method, it is extremely significant to avoid short sides, which is remarkable difference with others, participation in parameter solution.
Analysis of Galileo Signal Quality and Positioning Performance
ZHOU Xingyu, CHEN Hua, AN Xiangdong
2018, 43(1): 19-24. doi: doi:10.13442/j.gnss.1008-9268.2018.01.004
Abstract:
 Galileo system is one of GNSS, and it has preliminary obtained global positioning capability. The research of Galileo signal quality and bi/tri-frequency positioning performance not only contributes to Galileo system, but also promotes the fusion positioning of multi GNSS. On the basis of existing MGEX ground tracking stations, this paper focuses on the analysis of Galileo carrier to noise(CNR) ratio, code multipath delay, and the current stage of the precise point positioning (PPP) dual-frequency, triple-frequency static positioning accuracy. The results show that comparing Galileo and GPS, the CNR and multipath delay follow an order of E5> E5a≈ E5b≈L5>E1≈L1>L2 and E5≤E1
Analysis of Realization of Station Pointing Attitude for KX-02 Satellite
JIANG Hu, DENG Lei, YU Jinpei
2018, 43(1): 25-28. doi: 10.13442/j.gnss.1008-9268.2018.01.005
Abstract:
Spacecrafts usually keep a certain attitude in order that the payload onboard the S/C can remotely sense the targets of interest, and successfully get the interesting information about the targets during the flight mission. Two methods for realization of station pointing attitude are put forward. Therein, the influences of transformation matrices of different coordinate system on position of S/C are assessed. With these two methods fulfilled in S/C simultaneously, the station pointing attitude can be reliably and effectively realized.
Estimation of the Parameters of Nuclear Explosion based on GNSS Observation
SUN Yang, MIAO Jiayou, WANG Shuai, XIONG Wen, YU Xiao
2018, 43(1): 29-35. doi: 10.13442/j.gnss.1008-9268.2018.01.006
Abstract:
Acoustic-gravity wave induced by underground nuclear explosion will affect the ionosphere by generating travelling ionospheric disturbance (TID). Such effect can be studied by GNSS observation and the parameters of nuclear explosion can be calculated as well. Based on GPS data from several IGS stations, methods used for estimation of TID velocity and source location have been studied and the result confirms the feasibility of estimating the source location by GPS observations.
  Searching High-dimension Ambiguity Based on Self-adaptive Differential Evolution Algorithm
SUN Yanyan, LIU Cuizhi
2018, 43(1): 36-42. doi: 10.13442/j.gnss.1008-9268.2018.01.007
Abstract:
In this paper, a new algorithm is proposed to solve the problem of high dimensional ambiguity resolution. The self-adaptive differential evolution algorithm is used to fix the high dimensional ambiguity with its global, fast and parallel search. According to the characteristics of the problem to be solved, some parameters are reset on the basis of the original adaptive differential evolution algorithm so as to realize the quick search of the ambiguity. Based on the solution and operation rate of LAMBDA algorithm, the correctness of the algorithm and the rapidity of solution are verified. It is proved that the algorithm has certain application reference value for high dimensional ambiguity resolution, and it has good reliability and robustness by simulating and measuring the data with different dimensions.
  Dynamic Positioning Accuracy Test and Analysis of BeiDou Satellite Navigation System
ZHANG Fengzhao, LIU Ruihua, NI Yude, WANG Ying
2018, 43(1): 43-48. doi: 0.13442/j.gnss.1008-9268.2018.01.008
Abstract:
With the construction and development of BeiDou satellite navigation system, we are committed to providing stable, reliable and high quality satellite navigation services to global users and promoting the development of global satellite navigation in civil aviation. This paper introduces the positioning error of the satellite navigation system and the main factors that affect the positioning accuracy. By comparing with the GPS/INS navigation data as the true value data, the positioning accuracy of the dynamic test points in different altitude regions is analyzed. Firstly, the distribution of DOP and the number of visible stars in the measured data is simulated and analyzed for the high altitude mountain range and the low altitude plain area, and the dynamic positioning accuracy of the two kinds of altitude is statistically analyzed. The results of the measured data show that the Beidou satellite navigation system can provide real-time navigation and positioning services both in the low altitude plain and in the high altitude mountain range, and can calculate the dynamic positioning accuracy of the satellite system, and the positioning results are in compliance with the standards of "BeiDou satellite navigation system performance standards for public service", to meet the user's positioning requirements.
Test and Precision Analysis of BeiDou Ground  Augmengtation System
YANG Jianke, MO Nuo
2018, 43(1): 49-53. doi: 10.13442/j.gnss.1008-9268.2018.01.009
Abstract:
  To Combining with the Nanning BeiDou ground-based augmengtation system demonstration project actual production pyactice,the test of time availability, RTK positioning accuracy(including the effect after encryption station) and spatial availability had been done.The results show that the Nanning BeiDou ground-based augmengtation system meets cenmetre order for RTK positioning in all-day and 95% coverage of Nanning area.Compared with single GPS and single BDS,the combination of GPS+BDS in reliability.time availability fo RTK positioning under the hidden environment is improved obviously.
  Study on Feasibility of Real time Retrieval of Precipitable Water Vapor Based on Ultra-rapid Ephemeris
SHEN Jianhua, ZHAO Xingwang, XU Jiujing, LIU Chao, XU Yue
2018, 43(1): 54-59. doi: 10.13442/j.gnss.1008-9268.2018.01.010
Abstract:
 From the perspective of the practical application of ground-based GPS meteorology, it is a critical problem to obtain the atmospheric water vapor field of high spatial and temporal resolution in real time. Based on the principle of ground GPS water vapor remote sensing using Hong Kong CORS network of actual measuring data, according to the different precision of the orbit of IGS web site provides information design the experiment scheme, this paper compares the schemes of precise ephemeris, eventually ultra-rapid ephemeris and meteorological sounding station PWV sequence detection. The results show that the predicted PWV data of the ultra-rapid ephemeris agree with those of the final precise ephemeris, and its accuracy can meet the real-time business needs, such as weather forecasting.
  Modeling of Weighted Mean Temperature and its Application in GPS/PWV
XU Jiujing, ZHAO Xingwang, SHEN Jianhua
2018, 43(1): 60-64. doi: 10.13442/j.gnss.1008-9268.2018.01.011
Abstract:
The accurate acquisition of weighted mean temperature is critical to GPS inversion of atmospheric precipitation. Based on the linear regression theory, the correlation between weighted mean temperature (Tm) and surface temperature (Ts) is analyzed. Then linear regression is made to get the empirical formula of Tm with Hong Kong radiosonde data. The results show that the root mean square of the Tm using this paper’s model is 2.356  K, which is 41.94% higher than that of the Bevis model, and the effect of seasonal variation on the Tm accuracy is not significant. Finally, the model of this paper is applied to remote sensing atmospheric water vapor. The root mean square is 1.807 mm, and the mean deviation is 1.362 mm. The results indicated that the model of this paper for Tm can meet the accuracy of GPS inversion of atmospheric precipitation, and better than the Bevis model.
Design and Calculation Method of GIS High Precision Target Point Collector
CHEN Shiping, ZHUANG Guiyu, XU Binxiong, TAN Shucai, DING Rong
2018, 43(1): 65-69. doi: 10.13442/j.gnss.1008-9268.2018.01.012
Abstract:
Not for the use of satellite positioning or personnel is difficult to reach a collection of coordinate information of the target, this paper uses differential positioning module receives CORS network difference information can be obtained with high precision reference point coordinates, using a visible laser ranging module, electronic compass respectively target distance, azimuth and elevation, obtain high precision coordinates of target through calculation, only one measurement can obtain the coordinate of the target, reducing the difficulty of collecting outdoor GIS information, and can shoot the target site to upload, and automatically records the photos with the target coordinates and matching. The equipment has the advantages of low cost, high positioning accuracy, small size, low power consumption, easy to carry, simple development of the two time, compatible with data acquisition, etc.
  Performance Analysis of BDS/GPS Combination Kinematic Positioning in Different Environments
YU Longhao, DING Keliang, LIU Yajie, ZHAO Haitao, ZHOU Mingduan
2018, 43(1): 70-74. doi: 于龙昊 E-mail: yu415479771@163.com
Abstract:
This paper mainly discusses the positioning model of the combination system of Beidou and GPS, through the dynamic positioning experiments were carried out in different receiving environment, using carrier phase postprocessing technique for dynamic data processing, combined with the spatial distribution and location of environmental satellite, analyzed the single Beidou Satellite Navigation System, Global Positioning System, and positioning system performance. The results show that the observation conditions favorable environment, the positioning performance of combination system and global positioning system is basically the same, the Beidou Satellite Navigation System in the weaker; observation condition is not ideal environment, increase the number of visible satellites navigation system, improved satellite constellation structure, improve the positioning performance, the dynamic positioning performance is superior to that of the dynamic positioning performance the combination system of single system.
An Ambiguity Algorithm for Single Frequency and Single Epoch Combination of GPS and BDS
JIN Xing, WANG Ling, HUANG Wende, ZHOU Bang, LIU Wei
2018, 43(1): 75-80. doi: 10.13442/j.gnss.1008-9268.2018.01.014
Abstract:
Aiming at the problem of rank-defect and ill-conditioned ambiguity resolution in the process of single frequency single epoch combined RTK positioning, a new method for ambiguity decorrelation is proposed, in which pseudorange observations is introduced as auxiliary solution.First, we adopt the empirical decentralization method to assign weights to the pseudorange and carrier phase observations, and obtain the floating resolution of ambiguities by weighted least squares. Then the ill-conditioned ambiguity resolution can be eliminated by the descending order of variance-covariance matrix of the floating resolution of ambiguitiesand Cholesky triangular decomposition. Finally, we use the modified floating solution toiterate the search of the integer solution of ambiguity. The experimental results show that the down-correlation algorithm can not only improve the positioning accuracy, but also can reduce the correlativity of the ambiguity, which is suitable for RTK positioning.
Analysis of the Impact of Extra Long-baseline in GPS Data Processing with High Precision
YANG Dengke
2018, 43(1): 81-84. doi: 10.13442/j.gnss.1008-9268.2018.01.015
Abstract:
   According to the fact that there is no enough research of the extra long-baseline in GPS data processing with high precision. Focusing on the data of two CORS networks with different given points and dividing the processing time into the following six time periods: 4 hours, 6 hours, 8 hours,12 hours, 18 hours, this paper quantitatively analyzes the effects of different given points and extra long-baseline on GPS data processing with high precision. The result shows that extra long-baseline can make an effect on the accuracy of GPS data processing: the effect gets less as the increase of the processing time. And it also shows that the existence of the extra long-baseline has a relatively great effect on the result: when the given points locate worse, the maximum effect can reach 12.7mm, and when they locate better, the maximum effect gets to 6mm, and the effect is obvious in all of the 6 time periods. So the effect of extra long-baseline should be taken into consideration in GPS data processing with high precision.
The Application of Moving Least Square Method on Elevation Anomaly Fitting
ZHOU Pinghong, LI Zhifu
2018, 43(1): 85-90. doi: 10.13442/j.gnss.1008-9268.2018.01.016
Abstract:
  The anomaly of elevation has always been a concern in surveying and mapping field, and the commonly used fitting methods are based on least square method. In this paper, the method of moving least square method is used to make the elevation anomaly fitting, and the fitting accuracy is improved by the Engineering data. At the same time, the "fixed point method" is proposed for the determination of the radius in the least square method of moving, and the method can satisfy the fitting precision requirement.
Satellite Clock Error Prediction of Improved Polynomial and Periodic Mode
LIAO Jianfa, ZHANG Yanbing
2018, 43(1): 91-95. doi: 10.13442/j.gnss.1008-9268.2018.01.017
Abstract:
In order to solve the problem that accuracy of the existing ultra-fast clock error products is too low to meet the real-time PPP technology, an improved polynomial and periodic clock error prediction model is proposed. The model first uses the polynomial and periodic nonlinear function to make a sliding estimation of the clock error data, and then uses the iterative method to naturally correct the random error of the fitting model to realize the prediction and estimation of the satellite clock error. Compared with the common polynomial model, the gray system model and the polynomial and periodic model, the results show that the improved polynomial and periodic model is more suitable for satellite clock error forecasting, and RMS of the forecast results can reach 0.57 ns and the maximum deviation is 1 ns within a day, which is obviously better than the gray system model and the polynomial and periodic model. With the increase of forecasting time, the forecasting accuracy of the polynomial model, the gray system model and the polynomial and periodic model greatly decreases, while the improved polynomial and periodic model does not change significantly, and the forecast result is stable.
Study on the Application of BeiDou Satellite Navigation in AUV
WANG Yongding, LI Huanan, QIAN Yingjuan
2018, 43(1): 96-101. doi: 10.13442/j.gnss.1008-9268.2018.01.018
Abstract:
This paper analyzes the characteristics and advantages of different navigation and positioning technologies applied by AUV at work, introduces BeiDou navigation system and the AUV positioning principle based on BeiDou navigation system. On the application of BeiDou navigation system of AUV mechanical structure modular design of the four modules to carry on the detailed elaboration, logical process for the control of the AUV navigation control section and based on the logic of the hardware system design and build complete. The AUV platform of BeiDou navigation system is verified, and the operation is stable and consistent with the expected value from the self-directed cruise and autonomous cruise verification structure. With the continuous upgrading and upgrading of BeiDou navigation system, the application of BeiDou satellite navigation system in AUV will become more and more common.
Study of The Indoor Environment Testing Based on BeiDou System
HU Qingsong, WANG Peng, JIANG Bo
2018, 43(1): 103-106. doi: 10.13442/j.gnss.1008-9268.2018.01.019
Abstract:
 BeiDou system is our self-developed GPS navigation system, which is used widely because of its excellent properties.After the Internet,the Internet of Things is the another major revolution in information technology.The indoor testing technology has developed in a relatively mature height.This paper analyzes the applicability of the BeiDou system in the the indoor environment testing based on the architecture of the Internet of Things.So that BeiDou system can serve the indoor environment testing better and we can develop the indoor environment testing with Chinese characteristics by using the method of unique innovation.