全球定位系统

2017 Vol. 42, No. 6

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Improved Shadow Matching Positioning Algorithm Based on High Score Weighting

XIA Jingping, HU Hui, YAN Yujun, OU Minhui

2017, 42(6): 1-8. doi: 1008-9268(2017)06-0001-08

[Abstract](173) [PDF 1481KB](82)

Abstract:
Traditional shadow matching signal-to-noise ratio (SNR) threshold cannot distinguish LOS／NLOS effectively, resulting in larger positioning error because of inaccurate visibility of the satellites.Based on the analysis of the SNR characteristics received by the receiver in the urban canyon, an improved shadow matching algorithm based on high score weighting is proposed,and the results of improved algorithm are filtered by particle filterin the dynamicscene.Experimental results show that the average positioning error of the algorithm is 2.45 m and 4.64 m in static and dynamic scene, which is reduced by 38.1％ and 21.9％ compared to 3.96 m and 5.95 m of traditional shadow matchingpositioning algorithm.

Cycle Slip Correction and Rapid Re-convergences with Inertial Aiding for Precise Point Positioning Based on Geometry-specified Model

FU Fene

2017, 42(6): 9-15. doi: 10.13442/j.gnss.1008-9268.2017.06.002

[Abstract](416) [PDF 2002KB](55)

Abstract:
The loss of lock and cycle slip on GNSS signals occurs frequently in the GPSdenied environment where re-initialization forprecise point positioning (PPP)is usually required.It results in degrading theaccuracyand reliability of PPP. In this paper, an inertial aiding and geometry-specified cycle repair model is applied in PPP／SINS tightly coupled integration. The proposed model using uncombined observations builds the time-differenced carrier phase equations, which cycle slips are estimated and the displacement from inertial is treated as virtual observation for adjustment. When the cycle slips are fixed to correct integers, the original carrier phases are repaired accordingly to keep continues positioning with high precision. Two tests including vehicle and airborne data are analyzed to validate the proposed method. The results show that inertial aiding could accelerate PPP re-convergences significantly and success to repair cycle slips.

Performance Analysis of GPS／BDS／GALILEO Multi-system Combination Pseudo-range Point Positioning

JIA Xue, XU Wei

2017, 42(6): 16-23. doi: 10.13442/j.gnss.1008-9268.2017.06.003

[Abstract](1089) [PDF 2113KB](155)

Abstract:
Aiming at the difference of GPS,BDS,GPS／BDS,GPS／GALILEO,BDS／GALILEO,GPS／BDS／GALILEO intermodulation pitch single point positioning accuracy, the multi-system fusion pseudorange single point positioning The mathematical model and the error term processing method are studied. According to the experimental data of Hong Kong CORS station HKNW site, in the case of cutoff satellite elevation angles of 10, 15, 20, 30, and 40 degrees, the GPS, BDS, GPS／BDS, GPS／GALILEO, BDS／GALILEO and GPS／BDS／GALILEO pseudo range single point positioning calculations are carried out. The results show that the positioning accuracy of GPS／BDS／GALILEO system is better than that of single system in X, Y and Z directions, and the positioning result is more stable. Especially when the cutoff height angle reaches 30°and 40°,the positioning accuracy of single system The GPS／BDS／GALILEO combination system can still meet the requirements of positioning.

Change of Ionospheric Crest in China Sector Based on GPS-TEC

YU Houfang, ZHU Yunzhou, DENG Zhongxin

2017, 42(6): 24-29. doi: 10.13442/j.gnss.1008-9268.2017.06.004

[Abstract](379) [PDF 2183KB](107)

Abstract:
The variations of ionospheric TEC (total electron content) of equatorial anomaly are studied using the data from seven GPS sites of China region in 2004, including the occurrence latitude and time of the crest and the ionospheric gradient. Results show that the latitude of the crest varies from 17.5°N to 22.5°N in different seasons. It is higher in equinoxes and lower in winter, and the mean of occurrence latitude is about 20°N. The occurrence time of the crest varies also between 13 h and 16 h in local time (LT). It is earlier in winter and later in summer, and the mean time is about 14 h LT for the former and between 15 and 16h LT for the latter. It is found that there is the gradient of ionospheric TEC along the longitudinal chain, which vary with the local time and seasons. The minimum of gradient occur in nightside about 4.5 h LT and the maximum appears in dayside between 13 h and 16 h LT. Moreover, the variations of gradient is smaller in different seasons for the nightside and turn notable for the dayside, and the gradient is greater in equinoxes than summer and winter in dayside.

Research on Dynamic Precise Point Positioning Algorithm Based on INS Aiding

HAN Shuwen, LI Feng, LIU Feng

2017, 42(6): 30-35. doi: 10.13442/j.gnss.1008-9268.2017.06.005

[Abstract](306) [PDF 1666KB](43)

Abstract:
In Precise Point Positioning, the integer ambiguity does not have integer property, how to solve it accurately has always been a hot topic in recent research. Moreover, in the initial stage,a long time observation should be taken to make the positioning result converge to centimeter to decimeter level. In order to solve this two problems, the shorttime high accuracy positioning information output from the inertial navigation system can be introduced in ambiguity resolution, making the calculation faster and more accurately. The paper describes two kinds of least square methods, including using INS position information to substitute directly and building the virtual observation. Then, the relationship between INS accuracy and accuracy of ambiguity resolution are also discussed under two methods. The simulation result shows that the INS position aiding can effectively improve the efficiency and accuracy of ambiguity resolution, shorten the convergence time and improve the positioning accuracy.

An Integrated Map Matching Algorithm Based on Road Connectivity and Shortest Path

CUI Songlin, FENG Junhuan

2017, 42(6): 36-41. doi: 10.13442/j.gnss.1008-9268.2017.06.006

[Abstract](424) [PDF 1737KB](101)

Abstract:
Map matching algorithm of factor weighting method、road network topology and grid division is studied in the paper. The process of map matching is analysed,including map data preprocessing、the establishment of road connectivity、the calculation of the projection point and the road matching weight. Next, a map matching algorithm based on road connectivity is proposed,which uses the capture circle to obtain candidate road sets.When the GPS signal is loss, the shortest path algorithm is started to calculate out the way the car passed. Finally, the algorithm mentioned in the paper is compared with others by experiment. It is proved that the algorithm is with high matching accuracy, matching speed and practicability.

Algorithm Implementation and Result Analysis of Network-RTK Based on GPS／BDS

DU Wenxuan, YAN Chao, XU Wei, WANG Tao

2017, 42(6): 42-47. doi: 10.13442/j.gnss.1008-9268.2017.06.007

[Abstract](592) [PDF 1705KB](147)

Abstract:
With the development of GPS modernization, as well as the implementation of China's BDII, GPS／BDS integrated navigation system in the field of various industries and countries in the asiapacific region are increasingly widespread application, RTCM increased the BDS ephemeris message and support BDS carrier phase difference makes the big dipper foundation system is more important to its application in various industries. In this paper, the basic model of relative positioning, a single base station RTKwith multiple base stations gps-rtk basic principle as well as the VRS positioning method, through collecting GPS／BDS observation,analysis of single base station of RTK and base station positioning results.The results show that if the distance between the station and the base station is shorter, both multi-base station and single base station positioning accuracy can be obtained by the centimeter-level positioning results. The positioning accuracy of GPS／BDS dual-frequency multi-station RTK can reach the accuracy of centimeter-level and can be of high availability when the distance between the mobile station and the base station is longer.

Analysis of the Impact of Inclined Geosynchronous Orbit on BDS Triple-frequency Single-epoch Baseline Resolution

XU Mei, YAN Chao, QIAO Fang, SU Di

2017, 42(6): 48-54. doi: 10.13442/j.gnss.1008-9268.2017.06.008

[Abstract](361) [PDF 1763KB](52)

Abstract:
IGSO is a special geosynchronous circular orbit with good track stability, long control period, and can cover the high latitudes. On the basis of this, the influence of IGSO satellites on the accuracy of BDS triplefrequency singleepoch baseline resolution is studied. This article uses two short baselines in Inner Mongolia and Anhui, on the basis of the GEO and MEO satellites, an IGSO satellite was added to participate in the solution increase by visibility. The experimental results show that when adding 2-3 IGSO satellites with good visibility, the success rate of ambiguity resolution is the highest, and the positioning accuracy is the best; compared with the addition of 1-3 IGSO satellites, the ambiguity resolution success rate and the positioning accuracy were decreased when 4-5 IGSO satellites were added.

Solving Integer Cycle Ambiguity of GNSS Attitude Instrument by Nulling Antenna Array

SHI Rong, LIU Chang, ZHANG Wei

2017, 42(6): 55-60. doi: 10.13442/j.gnss.1008-9268.2017.06.009

[Abstract](349) [PDF 1744KB](96)

Abstract:
The GNSS nulling antenna array with multiple antenna cells is usually used to form the beam null in the direction of jamming with large power. This is an effective anti-jamming method. Here the 2D short baselines in a nulling antenna array are utilized. According to direction finding principle of multi-baselines interferometer in electronic reconnaissance, the measurement result of short baseline is naturally used to solve the phase difference ambiguity of long baseline for GNSS attitude instrument. In this way the integer cycle ambiguity from GNSS attitude instrument is removed in real time. In this method GNSS attitude instrument is combined with nulling antenna array. It enhanced not only the speed for ambiguity removing, but also the anti-jamming and anti-deception ability of the whole system. It is an important reference for the application development of GNSS attitude instrument and nulling antenna array.

Comparison and Analysis of Astronomical Refraction Correction Model

CHEN Shaojie, ZHENG Yong, ZHAN Yinhu, PU Junyu, LI Chonghui

2017, 42(6): 61-65. doi: 10.13442/j.gnss.1008-9268.2017.06.010

[Abstract](350) [PDF 1377KB](46)

Abstract:
Atmospheric refraction is one of the main factors which affecting the accuracy of astronomical measurement all the time. The paper introduces and summarizes several commonly used models in computing atmospheric refraction corrections, compare and analysis the effect of different models under standard atmospheric conditions. It shows the difference between different methods is very small when the zenith distance is smaller than 60°, but with the increase of zenith distance, the difference of different methods increases. High precision method must been setup for high precision astronomical measurements.

Research on Ambiguity Fixing Method of Reference Station with Zero Baseline Constraint

DING Lele, WANG Zhen, PAN Yuming, LI Lei

2017, 42(6): 66-71. doi: 10.13442/j.gnss.1008-9268.2017.06.011

[Abstract](221) [PDF 1668KB](77)

Abstract:
In this paper, a method for fast ambiguity resolution between reference stations with GNSS zero baseline constraints is proposed. The method is based on the design of "one antenna+two receivers". First of all, using the observations of four receivers on two reference stations, the double difference observation of the ionosphere free combination between four reference stations is constructed. Secondly, combined with the ionosphere ambiguity and the ambiguity of the whole lane, the real solution of N1 ambiguity is obtained by Kalman filter. Then, the linear transformation in the ambiguity domain, single epoch fixed zero baseline ambiguity; the relationship between the use of constraints of zero baseline ambiguity, calculated in the four groups a set of reference station ambiguity. Finally, all the original double difference ambiguities are solved by using the fixed ambiguity. Experiments show that compared with the traditional reference station, the ambiguity fixing method, make full use of the constraint of zero baseline ambiguity, accelerate the ambiguity speed, greatly improve the ambiguity speed and success rate.

Implementation of Data Sharing Service Platform for GNSS Applications User

ZHOU Bang, ZHOU Wei, HUANG Wende, PANG Hao, JIN Xing, LIU Wei

2017, 42(6): 72-78. doi: 10.13442/j.gnss.1008-9268.2017.06.012

[Abstract](225) [PDF 2251KB](56)

Abstract:
In order to achieve the application of GNSS data sharing, allow more users to make full use of existing data resources, break the constraints of data scarcity, reduce duplication oflabor and other costs, provide an effective and visual data sharing service byinteractive portal, we need to design an implementation of data sharing service platform.Thispaperanalyzes the user's need for data sharing platform interoperability, based on the SSM framework design of the B／S (browser／server) model GNSS application data sharing platform, for GNSS applications users provide staticand dynamic data downloads.The architecture of the data sharing platform is composed of data acquisition layer,data storage layer, data analysis layer, processing layer and data sharing layer.The loose coupling of various hierarchical features a clear mechanism, and has good scalability.

Research on Coordinate Transformation Between ITRF Frame and CGCS2000

ZHANG Jie, FAN Yulei, DONG Haizheng, LU Qun

2017, 42(6): 79-83. doi: 10.13442/j.gnss.1008-9268.2017.06.013

[Abstract](501) [PDF 1211KB](106)

Abstract:
The parameters of frame transformation from ITRF2005 to ITRF97 are deduced for calculation in this paper, and the frame transformation and epoch reduciton are researched deeply. With the data from the four IGS stations in China, the two transformation methods of frameepoch and epochframe are validated by examples. Finally this paper analyses the accuracy of conversion results and gives some suggestions for the use of coordinate transformation methods.

Study on Data Processing Method of Course Alignment Based on Dual Antenna Direction Finding

BAI Yudong, LI Jingyan

2017, 42(6): 84-87. doi: 10.13442/j.gnss.1008-9268.2017.06.015

[Abstract](303) [PDF 1169KB](111)

Abstract:
This paper mainly researches the course alignment using method of dual antenna direction finding in dynamic state, calculates measurement errors caused by antenna position and ship attitude, data processing method is proposed and used to test of ship navigation system,test results show that the proposed method can improve the precision.

Research Analysis of GPS Elevation Fitting Method

TANG Lijuan

2017, 42(6): 88-91. doi: 10.13442/j.gnss.1008-9268.2017.06.015

[Abstract](153) [PDF 1121KB](113)

Abstract:
This paper takes the inclined line survey area of 2111(3) working face of Xie Qiao mine in Anhui Province as an example, elevation conversion GPS／level measurement points in the region is realized by plane fitting, surface fitting, multi36 cm, the RMS is about 1.9 cm, the residual value of the checkpoint is 1～3.5 cm, The BP neural network in accordance with the accuracy of up to 1.92 cm and RMS in 1.37 cm, indicating the use of GPS measurement combined with the level of measurement data to fit the elevation anomaly, to calculate the normal high point of each GPS is a line Effective way to meet the needs of general engineering construction.

Accuracy Analysis and Application of Single Base Station CORS in Mine Surveying

SHI Changwei, HE Qingqing, CHEN Changkun, XIAO Ming, SU Di

2017, 42(6): 92-96. doi: 10.13442/j.gnss.1008-9268.2017.06.016

[Abstract](297) [PDF 1271KB](65)

Abstract:
The principle of CORS system and the composition and construction steps of the single base station CORS system, combined with the actual measurement of single base station CORS in Zhuji East mining area, the application of single base station CORS system in mine measurement accuracy is analyzed, through the analysis on the precision of single base station CORS system can be applied in the surface movement monitoring and superiority of application in the mine surveying.