GNSS World of China

2018 Vol. 43, No. 6

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Overview of Satellite Navigation Spoofing Signal Detection Technology
ZHANG Xin
2018, 43(6): 1-7. doi: doi:10.13442/j.gnss.1008-9268.2018.06.001
Abstract:
The detection of satellite navigation spoofing signal provides a precondition for spoofing interference suppression of satellite navigation receivers,which prevents the receivers displaying error positioning, speed measurement and timing information.After introducing the development of satellite navigation spoofing technology in the background of navigation war, this paper analyzes the difficulty,effect and adaptability of the main satellite navigation spoofing detection technologies, points out the most valuable spoofing signal detection technologies in satellite navigation receiver. At last,the trend and development direction of the spoofing detection research are summarized and prospected.
Performance Analysis Joint of GPS/GLONASS/Galileo Precise Point Positioning Under Occlusion Condition
TIAN Xiancai, ZHAO Xingwang, XU Miaoqiang
2018, 43(6): 8-13. doi: doi:10.13442/j.gnss.1008-9268.2018.06.002
Abstract:
For poor precision single point positioning performance of single GPS system under Occlusion Condition,to improve performance of precision single point positioning cross multisystem in this paper, By setting different Elevation mask angle, the environment around the city is divided into normal environment, general occlusion and heavy occlusion. Using GPS, GPS/GLONASS, GPS/Galileo, GPS/GLONASS/Galileo different modes respectively, the static PPP simulation experiments were carried out on four continuously operating reference stations in hong kong under the environment. the results show that multisystem combination can effectively remedy the shortage of satellites in the occlusion environment around the city, and the PPP performance of GPS/GLONASS, GPS/Galileo, GPS/GLONASS/Galileo combination is improved to varying degrees compared with that of a single GPS system.

RDSS Transmission Delay Random Number Generation Method Based on Kernel Estimation
XIA Tianqi, LIU Ruihua
2018, 43(6): 14-18. doi: doi:10.13442/j.gnss.1008-9268.2018.06.003
Abstract:
BeiDou satellite navigation system adopts RNSS and RDSS dualmode structure system, which not only has the navigation, positioning and timing functions of GPS and other systems, but also provides bidirectional short message information service, which has a very wide potential application in many civil fields. Transmission success rate and transmission delay are two important performance parameters of BeiDou short message. These two performance parameters are urgently needed as reference for the promotion and application of BeiDou short message technology in various industries and the construction of related systems. This paper tests the communication performance of BeiDou short message, proposing a method based on the kernel density estimation in order to establish the Beidou short message transmission delay probability model and generate the delay pseudorandom number. The kernel density of Beidou RDSS measured time delay is estimated by MATLAB and the probability density estimation curve is drawn. The probability density function of the time delay is obtained by fitting the probability density estimation curve with multiple normal distributions. The rejection method realizes the generation of the pseudorandom number of the Beidou RDSS transmission delay.
Satellite Navigation Usability Monitoring Technology
ZHANG Faxiang, LIN Li, YIN Zan, ZHEN Weimin
2018, 43(6): 19-24. doi: doi:10.13442/j.gnss.1008-9268.2018.06.004
Abstract:
Existing navigation and positioning systems include GPS, GLONASS, GALILEO, BEIDOU navigation system, collectively referred to as GNSS. With the continuous improvement of GNSS and the continuous promotion and application in various fields, the importance of navigation system is increasing. The satellite navigation usability directly affect the user experience and even the security of the user. The paper mainly discusses the related technologies of satellite navigation system usability monitoring, mainly from three aspects: satellite navigation system integrity monitoring, ionospheric scintillation monitoring technology and electromagnetic environment monitoring.
Simulation of GNSS/SINS/Photogrammetry Inteqrated Navigation using Asynchronous Federal UKF Algorithm
ZHOU Pengjin, LV Zhiwei, CONG Dianwei, JIA Zhengyang
2018, 43(6): 25-32. doi: doi:10.13442/j.gnss.1008-9268.2018.06.005
Abstract:
In the process of aircraft landing, in order to improve the accuracy of the integrated system and solve the problem of the traditional federal filter that the nonlinear system is easy to filter divergence. This paper analyze the advantages and disadvantages of the two system, propose a federal filter algorithm of GNSS/SINS/Photogrammetry, and derived the system’s error model. This algorithm can assist the SINS with the high precision of GNSS and Photogrammetry, utilizing the federal unscented Kalman filter to estimate errors of SINS. For non-equal interval data problems of multi-sensor, the information fusion of asynchronous non-equal interval federal filter algorithm use time and measurement update separation, and the corresponding improvements of the federal filter structure to reduce the complexity of the algorithm. Computer simulation shows that the position and attitude accuracy based on the UKF-FKF has been significantly improved comparison with traditional federal filter algorithm.
A Novel Correlation Method with High Efficiency for GNSS Signal Acquisition
DAI Zhichun, LIU Wenxiang, FENG Xin, SUN Guangfu
2018, 43(6): 33-36. doi: doi:10.13442/j.gnss.1008-9268.2018.06.006
Abstract:
The implementation of correlation layer in signal acquisition take up an important proportion of hardware resource in GNSS receivers. In order to reduce the quantization loss and used hardware resource, a novel correlation method with high efficiency is proposed. The resource of adder tree in acquisition module of proposed is half of traditional method, and the quantization loss is reduced by 0.3 dB, which could be used in GNSS receivers with low cost and power consumption demand.
Research on Water Body Extraction Method Based on GF-2 High Resolution Remote Sensing Image
LIU Shuangtong, WANG Mingxiao, YANG Shuwen, YANG Mingze, YANG Lihua
2018, 43(6): 37-43. doi: doi:10.13442/j.gnss.1008-9268.2018.06.007
Abstract:
For the characteristics of GF-2 satellite image data, the water information in Liujiaxia area is extracted by singleband threshold method, multi-band algorithm, normalized difference water index threshold method(NDWI) and the decision tree method combining singleband threshold method with shadow water index(SWI). At the same time, a decision tree classification method combining single-band threshold method and enhanced shadow water index(ESWI) is proposed.The comparison of the effects of these water extraction method is carried out. It is found that the decision tree classification method combining single band threshold method with ESWI can effectively eliminate the influence of most shadows, and the extraction effect is better than that of SWI. NDWI and multiband algorithm has a second extraction effect.The single-band threshold method has a poor extraction effect.
A Quick Rectify Method for Road Distortion in Orthophoto Production in the Third Land Survey
MA Ruifeng, DU Quanye, ZHANG Li, DONG Youqiang, JIANG Huiwei
2018, 43(6): 44-50. doi: doi:10.13442/j.gnss.1008-9268.2018.06.008
Abstract:
It is the basis for resource and environmental monitoring and census of national conditions when orthophoto is produced as the base map in land survey. Aiming at the large number of distorted areas existing in the orthorectified image, especially the road area, this paper proposes a new method. That is to say, Real-time local orthorectification is carried out by editing DEM in the road distortion area. It shows that the method achieves a rapid rectify of the image road distortion area, There is no obvious misalignment of the road edge area after rectifying the high-resolution satellite imagery of the GF-2 and TRIPLESAT-2 experimental data. In addition, through comparing the accuracy of a certain number control points in the road area, before and after local orthorectification, it also shows that the method significantly improves the accuracy of the road distortion area, whose planar accuracy is better than 4 m. and meeting the requirements of Orthophoto production accuracy of 1∶10 000.
Study on Influence of Orbital Perturbation on the Visibility of GNSS Satellite System
CAO Xinliang, WANG Bisong
2018, 43(6): 51-57. doi: doi:10.13442/j.gnss.1008-9268.2018.06.009
Abstract:
The influence of orbital disturbance on satellite visibility is analysed in view of the phenomenon that the orbital data is effected by the perturbbative force. With STK(Satellite Toolkit), the software of simulation of orbit, the orbit is researched from simulation using TowBoday J2 J4 and HPOP. Choosing Tow Boday J2 and HPOP, the software generate a report that analysis visibility of satellite constellation from ground measurement and control station. The simulation results show that satellitic orbit is effected by perturbation force. The orbit elements computed by perturbative orbit equation is accuracy. As it is more accurate, in HPOP model, the maximum error is 0.076°in latitude and 0.115°in longitude. In altitude, the maximum error is 3.226 km. The disturbances of satellitic orbit can influence visibility of satellite which work out the maximum error was 9.913 s.
Influence of Thermal Expansion Effect on GNSS Short Baseline Coordinate Time Series
LIU Xingwei
2018, 43(6): 58-63. doi: doi:10.13442/j.gnss.1008-9268.2018.06.010
Abstract:
Thermal expansion effect of antenna observation pier and bedrock can cause nonlinear change of coordinate time series of global navigation satellite system (GNSS) reference station. In this paper, the effects of thermal expansion on the periodic characteristics of GNSS short baseline time series are evaluated using longterm GNSS observations. The results show that the thermal expansion effect can induce seasonal annual signal of about 1 mm in vertical, and can well explain the periodic signal of GNSS short baseline time series, but has little contribution to the plane direction. However, the effect of thermal bending caused by uneven sunlight irradiation on the plane direction should be considered.
High Performance and Fast Positioning Algorithm for GroundBased Navigation Systems
GUO Li, ZHANG Xue, GUO Xiye
2018, 43(6): 64-68. doi: doi:10.13442/j.gnss.1008-9268.2018.06.011
Abstract:
The base station of the groundbased pseudo satellite is fixed, and it lacks the fast geometric change for the static or low dynamic users. It needs a long observation epoch to solve the problem of location calculation. In order to realize the fast calculation of the precision single point positioning of the groundbased navigation system, the TIKHNOV regularization algorithm and the pseudo satellite platform of the unmanned aerial vehicle (UAV) are proposed to assist the positioning of the pseudo satellite. The simulation shows that the addition of TIKHNOV regularization can improve the positioning accuracy of ambiguity to a certain extent, and the addition of the airborne pseudo satellite platform can not only make the positioning result converge quickly, but also improve the positioning accuracy of the ambiguity floating point solution. The combination of the two can make the location algorithm achieve optimization.
Noise Analysis of PANGA Coordinate Time Series
HE Xiaoxing, SUN Xiwen
2018, 43(6): 69-75. doi: doi:10.13442/j.gnss.1008-9268.2018.06.012
Abstract:
A 12-year coordinate sequence of 200 GPS reference stations in the PANGA observation network was selected. The AIC model used to estimate the noise characteristics of the criterion, and the effects of different data strategies on the establishment of the noise model are discussed. The results show that different data strategies have less influence on the establishment of noise model. The noise model of the base station coordinate sequence is mainly characterized by the PL+WN noise model. The influence of different stochastic models on the GPS station speed estimation is relatively small, but in U. The component influence is the most obvious; compared with the annual amplitude change under different strategies, the amplitude values in the E, N, and U directions are different, and the scale of the amplitude displacement is finally determined.
Study on the Non-linear Variation of the IGS Station Time Series inside China
DAI Hailiang, SUN Fuping, ZHU Xinhui
2018, 43(6): 76-81. doi: doi:10.13442/j.gnss.1008-9268.2018.06.013
Abstract:
Taking 8 IGS station time series inside China as research object, this paper analyzes the law of non-linear variation. First, the periods of station time series are obtained by spectral analysis, finding that the annual non -linear variation is a common role, it is just different in amplitude of variation; other periodic items vary from station to station, and the periodic law in vertical direction is the most obvious. Then station time series are fitted by triangle method according to the periodical rule, the results show that it can exhibit the law of non-linear variation directly, which is beneficial to further analyze the property and mechanism of non-linear variation. The results would provide important reference for establishing and maintaining the high-precision terrestrial reference frame.
Data Security and Protection for iGMAS
LIU Chang, DING Fan
2018, 43(6): 82-86. doi: doi:10.13442/j.gnss.1008-9268.2018.06.014
Abstract:
iGMAS (international GNSS Monitoring and Assessment System) is a platform to monitor the BDS and evaluate the available system performance, servicing various users and applications with different products. It has been attached great importance to the system security,with the data security as one of its key points, in iGMAS development. In the paper, the potential risks are analyzed with the focus on data security for iGMAS based on the experience achieved in developing information systems alike to iGMAS. The analysis is made from various aspects including data communication, data transmission and verification, and data storage. Protection scheme is elaborated with the technology and management measures accounted.
Analysis of Fitting Accuracy of Satellite Orbit Based on BDS Broadcast Ephemeris
LI Zhenchang, LI Zhongqin, KOU Ruixiong
2018, 43(6): 87-91. doi: doi:10.13442/j.gnss.1008-9268.2018.06.015
Abstract:
In real-time positioning and navigation,in order to improve the efficiency of calculating the satellite position using the broadcast ephemeris of BDS,it is proposed to fit the satellite orbit to a polynomial. Firstly,using Chebyshev polynomial fitting method, the fitting period was fix to 1 h,the fitting interval was fixed at 5 min,and a checkpoint was selected every 30 s, different fitting orders was used,the Beidou satellite orbits of three different types of geostationary earth orbit,medium earth orbit and inclined geosynchronous orbit was fitted and analyzed. Then, the fitting order is fixed at 9, and the orbits of three types of satellites as a whole is fitted and analyzed using a fitting interval of 2 to 6 minutes..The example shows that as long as the appropriate fitting order is selected,the Beidou satellite orbit fitting accuracy of the three different types of orbits is high.The maximum fitting error is in the centimeter level,and the average error is in the millimeter level, which satisfies the precision requirements. When the fitting polynomial is fixed at the 9th order, the fitting accuracy of 2~6 min time interval can meet the precision requirement.The Chebyshev polynomial fitting method is suitable for the fitting of the satellite orbit of BDS broadcast ephemeris.
Application of the Qianxun SI CORS-RTK in the Foundation Pit Staking
DONG Yongxiang
2018, 43(6): 92-97. doi: doi:10.13442/j.gnss.1008-9268.2018.06.016
Abstract:
For the problem that the target lofting area is blocked by the wall and the base station is located at the center of the road, the traditional total station lofting method and the single-base CORS RTK lofting method cannot be used. Qianxun SI service system and the network CORS-RTK method are used to stake out the foundation pit in the engineering construction. The principle and advantages of the network CORS are introduced, and the data of the lofting points are processed and the lofting accuracy is analyzed in the paper. The results show that the plane coordinates of 37 lofting points are measured by RTK, the error in the X direction within 20mm is 97%, the error in the Y direction within 20mm is 100%, which is relatively concentrated and stable; 95% of the error in the position is less than 20 mm, 5% of the error in the position is 20-40mm, the error in the measurement point of the CORS-RTK method meets the accuracy requirement of less than 70 mm in the plane point required by the National Satellite Positioning City Measurement Technical Specification CJJTT73 2010. The CORS measurement of Qianxun SI meets the accuracy requirements of engineering specifications and is of great significance for reducing the workload of engineering construction.
Study on the Characteristics of the Ionospheric TEC Disturbances Caused by Typhoon Based on GroundBased GPS Data
XU Jiujing, KE Fuyang, ZHAO Xingwang
2018, 43(6): 98-104. doi: doi:10.13442/j.gnss.1008-9268.2018.06.017
Abstract:
The way to study ionosphere used the Global Position System has many advantages of all-weather, high-resolution and wide-range. Based on the sliding interquartile range method and with the ionospheric TEC data which is extracted from GPS dual observation and GIM, this paper studies the feature of the ionospheric TEC disturbances caused by typhoon at its passage areas and landing site. The results show that the day before the typhoon landed in Xiamen, the TEC has a strong positive disturbance, and there is a small-scale negative disturbance occurred the day after landing; Before the typhoon approached Taiwan Island, there is a widely range of positive ionospheric anomaly disturbances whose value is 15~20 TECU and the duration is 10 h in the typhoon-affected areas. Combined with the terrain of Xiamen and Taiwan Island, it is inferred that the TEC anomaly is due to the propagation of acoustic gravity waves induced by typhoon into the ionosphere altitude.
Design of Football Training System Based on BeiDou Smart Bracelet
LUO Shulei, FENG Yi, WANG Shiyin
2018, 43(6): 105-109. doi: doi:10.13442/j.gnss.1008-9268.2018.06.018
Abstract:
The BeiDou Navigation Satellite System(BDS) independently researched and developed in China has gradually matured and is widely used in the civilian field. There are still many shortcomings in football training in China. Improper football training not only causes poor training effect, but also may does harm to the athlete's body. In view of the above problems, this paper designs a soccer training system based on Beidou smart bracelet. Blending BDS, multi-sensor fusion technology, Internet technology, 3D video technology and wireless communication technology, the smart bracelet has high-precision real-time positioning, blood pressure measurement, heart rate detection, speed and acceleration measurement, motion recognition, onebutton alarm and track record and other functions to improve the scientific, safety and pertinence of training.
GPS-Based Segmented Elevation Benchmarking Transfer Experiment and Analysis
ZHANG Tao, CHEN Meng, ZHANG Piya
2018, 43(6): 110-114. doi: doi:10.13442/j.gnss.1008-9268.2018.06.019
Abstract:
There is no doubt that the elevation benchmarking is an important part of engineering application. Obtaining a stable and reliable elevation benchmark is an indispensable part of engineering construction. GPS positioning technology is a reliable method. In order to solve the problem of how to transform the height of the GPS into the normal high, this paper proposes a segmented elevation fitting method combined with elevation fitting models. Combined with a mine project data and the overall elevation transmission for comparative analysis, some useful conclusions are drawn.
Analysis on Positioning Performance of Vehicle Navigation and Positioning Terminal
YUAN Dao, LV Weicai, YUAN Xiaoxin, XU Miaoqiang, CHU Min, PENG Xiaoqiang, GE Xiang
2018, 43(6): 115-119. doi: doi:10.13442/j.gnss.1008-9268.2018.06.020
Abstract:
The principle of vehicle terminal combination positioning is introduced, and several methods for verifying the positioning accuracy of positioning of the terminal are proposed, including static positioning test, dynamic positioning test and general inspection. Experiments were carried out on the terminal to simulate the real scene. The experimental data of static state, occlusion environment, and road test were processed and compared with high-precision data to calculate the RMS “root mean square”of the terminal location (Root Mean Square). RMS), and matching the positioning data to the electronic map, showing good positioning and map matching results, based on theory,which conclude that the accuracy of terminal positioning meets the requirement of practical application.
Design of Ship’s Engine Room Temperature Monitoring System Based on BeiDou and Embedded System
CUI Xiufang, LI Zhigang, WANG Hongyu, CHEN Gang
2018, 43(6): 120-125. doi: doi:10.13442/j.gnss.1008-9268.2018.06.021
Abstract:
With the wide application of artificial intelligence, automatic control and network communication technology in the field of ship, the monitoring system of ship’s engine room becomes more intelligent, digitized, and modular. The Beidou satellite navigation system developed in China has the functions of location, navigation, time service and two-way short message communication, which is especially suitable for the field of ship monitoring. Temperature monitoring is an important part of engine room monitoring. In order to solve the problem of inconvenient temperature monitoring and find the way to control in engine room, a ship’s engine room temperature monitoring system based on Beidou and embedded system is proposed. The temperature collection system, ARM processor and its peripherals, equipment control devices and WiFi communication modules are used to monitor and control the temperature of the ship's engine room in real time. With the Beidou communication system as the medium, the temperature data collected from the engine room and the ship's position are transmitted to the remote monitoring terminal in real time. Not only does it simplify the hardware and software of the system, but also it enhances the real-time and operability. At the same time, it improves the confidentiality and stability, and has good prospects for development.