GNSS World of China

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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Analysis of the impact and effects of the solar storm on the ionosphere from May 8 to 16, 2024
WANG Shuai, QUAN Lin, LI Ling, WANG Kunpeng, HUANG Jian, YUAN Gang
 doi: 10.12265/j.gnss.2024107
[Abstract](32) [FullText HTML](12) [PDF 5660KB](1)
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Solar storms can cause severe disturbances to the state of Earth’s ionosphere and affect navigation and positioning performance. According to the ionospheric disturbance event occurring during the solar storm from May 8 to 16, 2024, the changes of ionospheric total electron content, ionospheric total electron content change rate, ionospheric F2 layer critical frequency, satellite navigation single point positioning error and so on at different latitude stations in the eastern and western hemispheres are analyzed. The analysis result shows that the sun-lit hermisphere of the ionosphere will respond to X-ray flares, but the main source of the disturbance is the geomagnetic storm caused by the solar wind southward magnetic field energy injection. The responses at the top and bottom of the ionosphere during solar storms are not synchronized; The single point positioning error of satellite navigation will increase significantly during the solar storm, especially in the vertical direction it will increase to about ±10 m. It will continue to exist during the recovery phase of ionospheric storms, and gradually weaken with the calm of the ionospheric state.
Application research of RINGO software in multi-system GNSS data preprocessing
FAN Jiuguo, LI Jianyong
 doi: 10.12265/j.gnss.2023202
[Abstract](235) [FullText HTML](81) [PDF 4282KB](44)
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Data preprocessing is a prerequisite for achieving high-precision positioning with the Global Navigation Satellite System (GNSS) and is also a vital step in data processing. As the number of satellite systems, numbers, and versions of Receiver Independent EXchange format (RINEX) increase, the GNSS data types and formats become progressively complex. Thought there are various data preprocessing software options available, multiple programs are required to complete the preprocessing stage, resulting in inefficiency and complexity. Therefore, to achieve efficient data preprocessing, developers have created the “RINGO” data preprocessing software, which supports all RINEX versions of multi-system data preprocessing. To achieve effective data preprocessing, developers created the “RINGO” software which supports all RINEX versions of multi-system data preprocessing. The study demonstrates the main functions, usage and principles of RINGO, with a focus on investigating and explaining confusing functions such as receiver clock jump correction. The test results demonstrate that RINGO can effectively and independently preprocess vast amounts of multi-system GNSS data, which can significantly ease the complex task of GNSS data management and foster the adoption of the latest version of RINEX observation records.
Architecture design of radiation source positioning system based on TDOA
HU Anyi, WANG Dengliang, QIN Bingkun, ZHANG Faxiang
 doi: 10.12265/j.gnss.2023174
[Abstract](132) [FullText HTML](97) [PDF 2726KB](16)
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To ensure the normal application of the Global Navigation Satellite System (GNSS), monitoring and localization of GNSS interference radiation sources are required. This paper presents the design of a radiation source positioning system architecture. By designing the system functions, architecture, grid monitoring equipment and workflows, high-precision time synchronization and reliable time difference measurements are achieved using BeiDou/GPS timing + high-stability crystal oscillators and a generalized weighted time delay estimation algorithm, which ensures the accuracy of time difference of arrival (TDOA) localization. The effective location of radiation source is realized through system application test.
2024, 49(4).  
[Abstract](12) [FullText HTML](7) [PDF 1297KB](2)
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Special Issue on “Satellite Navigation Information Security”
2024, 49(4): 1-1.  
[Abstract](26) [FullText HTML](17) [PDF 1668KB](2)
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2024, 49(4): 2-2.  
[Abstract](7) [FullText HTML](6) [PDF 1432KB](0)
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Design of satellite navigation service performance evaluation and interference monitoring protection system
LI Teng, JIANG Dongwei, LI Jinlong, HU Xiaoping
2024, 49(4): 3-9.   doi: 10.12265/j.gnss.2024113
[Abstract](20) [FullText HTML](15) [PDF 2130KB](0)
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The satellite navigation signals have inherent vulnerabilities and are highly susceptible to both intentional and unintentional electromagnetic interference. Therefore, conducting monitoring and evaluation of satellite navigation service performance and interference signals is of significant importance for supporting the operational services of navigation systems and ensuring the security of spatio-temporal information applications. This paper addresses the mechanisms and characteristics of monitoring and evaluating satellite navigation service performance. In conjunction with the practical needs for interference monitoring and troubleshooting, it presents an overall architecture for system construction and operational processes. Furthermore, it conducts research and analysis on the key technologies necessary for enhancing system effectiveness, providing comprehensive guidance and technical support for the engineering construction of a navigation application monitoring and support system characterized by “multi-source integration, wide-area coverage, three-dimensional perception, and rapid response”.
Differential privacy-based cooperative positioning for satellite internet
TAO Yihang, LI Jianhua
2024, 49(4): 22-27.   doi: 10.12265/j.gnss.2024032
[Abstract](55) [FullText HTML](14) [PDF 2316KB](7)
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Satellite internet provides positioning, navigation and timing services for the whole world based on the Global Navigation Satellite System (GNSS), but the data containing users’ location information will be leaked during GNSS cooperative positioning process, which poses a threat to users’ privacy security. To address the current privacy-protection challenges in GNSS cooperative positioning systems, this paper proposes a differential privacy-based cooperative positioning method for GNSS systems. The method first generates the perturbed position and randomly selects one to calculate the positioning collaboration data under the premise of satisfying the privacy budget, so as to prevent the user’s location from being leaked during the collaboration process. The experimental results show that the proposed method can effectively protect user location privacy while guaranteeing real-time and accurate positioning service, which provides a theoretical reference for the research of GNSS cooperative positioning information security.
An optimized deployment method for satellite navigation distributed suppression of interference
XIAO Yifan, LIU Weiping, YU Jiashu
2024, 49(4): 92-98.   doi: 10.12265/j.gnss.2024028
[Abstract](50) [FullText HTML](20) [PDF 2705KB](4)
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Satellite navigation has been widely used in various fields of human production and life, however, due to weak landing signals and other reasons, satellite navigation signals are prone to interference. In practical applications, distributed suppression jamming has become an effective means of satellite navigation jamming because of its advantages such as large coverage area and difficult detection. In this paper, the visual field algorithm based on the reference surface is used to calculate the interference range of a single jamming station in a specific terrain, and on this basis, a cyclic iterative method is used to find the optimal layout scheme of distributed jamming suppression. Experimental analysis shows that under experimental conditions, the distributed suppression interference coverage rate of the proposed method is more than 98%, which is obviously better than 74.18% of the traditional high-power single interference source. At the same time, the key suppression interference targets can be further highlighted and multiple suppression interference can be realized by setting red and green zones reasonably.
Maritime rescue terminal based on BDS short message and emergency position indicating radio beacon
MA Jun, NIE Guigen, LIAO Mi, GAO Wenliang
2024, 49(4): 107-112.   doi: 10.12265/j.gnss.2024057
[Abstract](21) [FullText HTML](13) [PDF 2310KB](0)
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Traditional maritime rescue terminals suffer from insufficient positioning accuracy and real-time performance. A maritime rescue terminal is designed for combines the functions of BDS short message and Emergency Position Indicating Radio Beacons (EPIRB). Combined with the command center and related software systems, it can achieve rapid reporting and precise positioning of distress. BeiDou Navigation Satellite System (BDS) short message communication can send messages between terminals and satellites. The COSPAS-SARSAT is an important component of the maritime distress search and rescue system implemented by the International Maritime Satellite Organization. It uses signals sent by EPIRB to locate accident locations and information. Combine the BDS short message with EPIRB, and assemble positioning modules and temperature, heart rate, and other sensors. When the holder is in danger, the terminal will immediately continuously send distress information to the command center, which can provide support for the rescue mission through analysis by the command center. After testing, its dynamic and static positioning accuracy has reached the level of 10 meters; BDS short message, EPIRB working well.
Localization for GNSS interference sources based on weighted K-Means combined with DRSS positioning
CHENG Hanqing, ZHANG Guomei, PENG Kejun
2024, 49(4): 113-120, 126.   doi: 10.12265/j.gnss.2024025
[Abstract](40) [FullText HTML](15) [PDF 2975KB](2)
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The carrier to noise ratio (CNR) based interference positioning in Global Navigation Satellite System (GNSS) has the problem of high localization difficulty and the low localization precision under the scenarios with multiple interference sources, multi-path transmission and long distance between receivers. Aiming at this problem, a multi-interference localization scheme that combines the weighted K-Means clustering with different receiver signal strength (DRSS) and equation solving based method is proposed in this paper. Assuming that the number of interference sources is determined and a single receiver is only affected by one interference source, the improved weighted K-Means clustering algorithm is designed to realize the initial estimation for multiple interference sources. In order to reduce the positioning error of the weighted K-Means clustering when the distance between receives is long, the receiving CNR affected more obviously by interference within each cluster are used to build the localization equations based on DRSS after clustering processing. To solve the equations can obtain the more accurate localization results. Simulation results demonstrate that the proposed scheme can realize the multi-interference localization. Compared with the scheme only including weighted K-Means, the average positioning errors of the proposed method involving DRSS parameters can be reduced by more than 19% and 38% under the two cases of single source and two single-tone sources, respectively.
Special Issue on “Satellite Navigation Information Security”
Introduction of ICG IDM and technology analysis of GNSS interference detection and localization
JIN Ruimin, ZHEN Weimin, HAN Chao, CHEN Li, CHEN Qidong, YANG Huiyun, CUI Xiang, GU Mingyue
2024, 49(4): 10-21.   doi: 10.12265/j.gnss.2024039
[Abstract](25) [FullText HTML](12) [PDF 3256KB](4)
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Global Navigation Satellite System (GNSS) is widely used in all walks of life. However, GNSS signals are very weak and the civilian signal format is known, making it extremely susceptible to various intentional and unintentional electromagnetic interferences, which poses a serious threat to GNSS applications. GNSS interference has attracted widespread international attention, the International Committee on Global Satellite Navigation Systems (ICG) has established a special GNSS interference detection and mitigation (IDM) working group to develop IDM technologies and exchange ideas on IDM system construction. This paper introduces the situation of ICG IDM, and analyzes the research progress of GNSS interference detection and localization technology and IDM systems. It provides important technical reference and research support for deepening the theoretical and technical research on GNSS interference monitoring and ensuring the safety of satellite navigation.
Research on the application of navigation countermeasures in the Russia-Ukraine Conflict
JIA Zanjie, YU Heli, WU Zhijia, DAI Taogao
2024, 49(4): 28-33, 41.   doi: 10.12265/j.gnss.2024026
[Abstract](29) [FullText HTML](17) [PDF 4320KB](0)
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The Russia-Ukraine Conflict is one of the major hotspot of the international situation. This paper reviews the situation of Russia and Ukraine navigation countermeasure equipment. Based on the IGS monitoring data near the conflict area and the military actions of Russia and Ukraine, this paper analysis the measures taken by Russia and Ukraine to fight for control of navigation resources in the conflict, and deeply studied the application methods of navigation confrontation between the two sides. Through analysis, it can be concluded that satellite navigation signals in conflict zones are one of the important sources of battlefield intelligence. Combined with other reconnaissance methods, comprehensive analysis and judgment can comprehensively reflect the military dynamics of the battlefield.
GNSS interference localization technology using the carrier-to-noise ratio measurements of the receivers
LIU Zhijian, YAO Zhiqiang, DENG Min, PENG Deyi, JIANG Fan
2024, 49(4): 34-41.   doi: 10.12265/j.gnss.2024033
[Abstract](63) [FullText HTML](16) [PDF 2609KB](5)
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Due to the low signal strength of GNSS signals upon reaching the ground, they are highly susceptible to unintentional or intentional human interference, which can severely impact the availability of navigation and positioning services. Therefore, locating and eliminating sources is of paramount interference. For common jamming interference, current positioning methods mainly involve processing the raw sampled signals, which often leads to issues with complex equipment, high computational demands, and high costs. This paper proposes a method for locating GNSS interference source using the carrier-to-noise ratio (C/N0) measurements from standard commercial receivers. By estimating the interference signal strength difference through C/N0 measurements, the position of the interference source can be calculated. Field test results indicate that, under line-of-sight conditions, in a monitoring area of approximately 11 400 square meters, this method can achieve a Mean Absolute Error (MAE) of 13.17 meters with minimal time consumption, thereby effectively locating the interference source. The proposed method does not require any modifications to the receiver's hardware or software, making it simple to implement and cost-effective, which is advantageous for engineering applications.
Analyzing the security of RDSS system from the perspective of information security
ZHANG Tao, NIE Guigen, MA Jun
2024, 49(4): 42-47.   doi: 10.12265/j.gnss.2024055
[Abstract](23) [FullText HTML](11) [PDF 2732KB](0)
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This paper analyzes the security advantages of radio determination satellite service (RDSS) in terms of signal structure and operation mechanism, and studies the potential security risks and countermeasures of RDSS from three aspects of information security: confidentiality, integrity, and availability. In particular, the use of radio frequency recording and replay (RAR) to verify the potential counterfeiting and deception security risks of RDSS has been studied prove that RDSS has vulnerabilities in resisting RAR attacks and is easily deceived by RAR attacks. The success of this deception attack exposes the security risks in the integrity and availability of the RDSS system, which can cause information confusion for end users and may also limit the frequency of attacks, preventing them from receiving normal services. Finally, several measures were proposed to improve system security in response to such security risks.
Consistency deception detection technique for GNSS/INS based on open-closed-loop alternation
CHENG Yuyang, PENG Xinzhi, FENG Fan, XU Yiyu, YUAN Xuelin, ZHU Xiangwei
2024, 49(4): 48-55, 65.   doi: 10.12265/j.gnss.2024020
[Abstract](35) [FullText HTML](17) [PDF 3392KB](2)
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The Global Navigation Satellite System (GNSS) and inertial navigation system (INS) are widely used in fields such as vehicles and drones. However, GNSS receivers are susceptible to deceptive signals. Therefore, this paper proposes a consistency deception detection technique using INS observations. Inertial devices have the characteristics of being less susceptible to deceptive signal interference and prone to cumulative errors. By alternately feeding back estimated errors in an open-closed loop manner, a GNSS/INS integrated navigation system is constructed. During the open-loop period, a deception detection window is established, and the consistency between the statistical detection measurements of the inertial device, acceleration, and angular velocity obtained from GNSS is evaluated to determine the presence of deception. Experimental results demonstrate that with a window time of 70 s, the detection probability reaches 99.2% while the false alarm probability is 5.2%.
A novel GNSS spoofing interference detection technology based on SQM
DENG Min, LIAO Xinlu, GUO Yingying, YAO Zhiqiang
2024, 49(4): 56-65.   doi: 10.12265/j.gnss.2024017
[Abstract](45) [FullText HTML](13) [PDF 3167KB](3)
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The Global Navigation Satellite System (GNSS) plays a strategic role in positioning, navigation, and timing in infrastructure application. Given the characteristics of GNSS signals such as extremely low landing power and transparent civil code structure, civil satellite signals are extremely vulnerable to interference and spoofing attacks, which makes GNSS suffer from serious interference problems. In this paper, to address the problems of low detection probability and poor reliability of traditional SQM (signal quality monitoring) detection quantities, we propose a new type of SQM detection quantities without the carrier phase information of tracking loop. Then, the metric values are moving averaged to reduce the effect of abnormal fluctuation value on the false alarm probability. Besides, the statistical distribution characteristic of the proposed metric is derived. The computation threshold and measurement threshold without a priori information are set up. The proposed method can avoid the failure detection when the relative carrier phases of spoofing and authorized satellite navigation signal are integer multiples of π. The comparison experimental results based on the public database with real measured signals of TEXBAT (texas spoofing test battery) show that the proposed algorithm is able to detect spoofing attacks with better accuracy in a shorter time under different real signal scenarios. The research results are valuable for the development of anti-spoofing communication devices in the future to improve the detection performance effectively without making large-scale changes to the hardware structure of the receiver.
Research on GNSS spoofing interference detection for multi-correlator combined power
ZHAO Shen, LIAO Yifei, LI Shiling, ZHOU Kaijun
2024, 49(4): 66-74.   doi: 10.12265/j.gnss.2023235
[Abstract](47) [FullText HTML](19) [PDF 3548KB](4)
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Global Navigation Satellite System (GNSS) civil signals are vulnerable to external spoofing because of their openness and vulnerability. As an effective method for spoofing detection, Signal Quality Monitoring (SQM) monitors the correlation results of early code, late code and phase code (ELP) after the receiver's tracking loop, and compares them with the correlation characteristics without spoofing to determine whether spoofing interference exists. The conventional SQM algorithm uses only three ELP information and the detection performance is limited. Therefore, a multi-correlator combined power algorithm is proposed. The weight of the output power of multiple equally spaced correlators between ELP is taken as the detection quantity, and the inverse ratio of the correlation time and the real-time code time difference is taken as the weighting coefficient. The probability distribution characteristics of the detected quantity were further analyzed, and the optimal detection threshold was determined based on the Neyman-Pearson theory. By comparing the detected quantity and the detection threshold, the existence of deception interference was determined. Based on the Scenario 4 set published by the University of Texas, the test results show that compared with typical SQM algorithms such as Ratio and ELP, the proposed algorithm has both high detection probability and fast early warning response time under different false alarm rates.
Anti-spoofing technology based on array antenna signal processing
LU Jianjun, PENG Xinzhi, FENG Fan, HUANG Chuhan, YUAN Xuelin, ZHU Xiangwei
2024, 49(4): 75-85.   doi: 10.12265/j.gnss.2024019
[Abstract](55) [FullText HTML](21) [PDF 2491KB](4)
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Global navigation satellite systems play an important role in national infrastructure as well as life safety applications, but the increasing spoofing incidents pose a great threat to GNSS. This paper introduces the anti-spoofing technology based on array antenna signal processing, and summarizes the spoofing interference detection and spoofing interference suppression methods from both uniform and sparse arrays according to the different array configurations. Compared with uniform array, sparse array has larger array aperture and degree of freedom under the same number of antenna elements, which greatly reduces the cost of equipment, but its coherent signal processing technology requires more. Finally, this paper gives the difficulties faced by the anti-spoofing interference technology and its future development trend.
The time spoofing detection method based on Long Short-Term Memory network
SHENG Menggang, SHENG Siyuan, DENG Min, WANG Liliang, YAO Zhiqiang
2024, 49(4): 86-91.   doi: 10.12265/j.gnss.2024034
[Abstract](35) [FullText HTML](33) [PDF 2628KB](0)
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Temporal and spatial information security is fundamental to the safety of national critical infrastructure. Disruption or interference with the time system can cause significant economic losses to the nation, and even pose a substantial threat to defense security. Existing timing deception detection methods primarily establish models based on the characteristics of changes in the receiver’s clock model to detect deception. However, due to the uncertainty of attack methods and the system errors inherent in the established receiver clock model calculation and fitting process, accurate fitting of the clock model parameters is difficult, and the environmental adaptability is low. To address this, this paper proposes a timing deception detection method based on the Long Short-Term Memory (LSTM) network. This method does not require consideration of the attack methods of timing deception, and has strong generalization capabilities. By utilizing the excellent time series prediction ability of LSTM, the method accurately tracks the trend of changes in receiver clock differences before and after timing deception based on the characteristics of these changes, achieving effective detection of timing deception interference. Finally, experiments and analyses are conducted using TEXBAT (Texas spoofing test battery) timing deception scenario data, and a comparison is made between LSTM and Multilayer Perceptron (MLP) networks. The results indicate that the performance of LSTM timing deception detection is superior to that of MLP.
Research on GNSS spoof detection method based on PCS combined with Ratio
ZHAO Shen, HU Yong, LI Shiling, XIA Yi
2024, 49(4): 99-106.   doi: 10.12265/j.gnss.2023234
[Abstract](36) [FullText HTML](22) [PDF 2994KB](2)
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A spoofing detection algorithm based on power combind with signal quality montoring(PCS) combind with Ratio(PCSR) is proposed to improve the performance of spoofing detection, in response to the problem of high fluctuation in the detection performance of PCS during the traction stage. The fusion process of the PCSR algorithm uses a weighting factor to linearly weight the amplitudes of the processed PCS and Ratio, and adjusts the contribution of PCS and Ratio to PCSR by changing the weighting factor.The experiment used data scenario 4 (DS4) of texas spoofing test battery (TEXBAT) from the University of Texas at Austin as the dataset to compare and analyze the deception detection performance of PCS, Ratio, and PCSR algorithms. The experimental results show that PCSR has higher detection probability and accuracy, better immediacy and robustness, and a wider detection range. The proposed PCSR algorithm combines the advantages of both PCS and Ratio algorithms and has better spoofing detection performance.
Research on jamming methods of satellite navigation and positioning system in UAV defense
GENG Zeqi, YU Heli, JIA Zanjie, CAI Yong, TANG Bin
2024, 49(4): 121-126.   doi: 10.12265/j.gnss.2024068
[Abstract](29) [FullText HTML](14) [PDF 2560KB](2)
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In view of the increasingly vicious UAV “black flight” phenomenon, and considering that its satellite navigation terminal will be loaded with multi-array adaptive zeroing anti-jamming antenna to improve the use of navigation resources, the advantages of using satellite navigation jamming for UAV defense are analyzed, and a satellite navigation jamming method for UAV defense is explored. The implementation strategy of navigation jamming from single interference source to multi-interference source is described, and the evaluation index is given. It helps protection personnel to accurately explore effective defense boundaries, determine weak areas, optimize interference source deployment strategies, and improve protection efficiency. A defense effect evaluation software is developed, which can present the defense situation and make the defense effect display more intuitive.
Construction and development of satellite navigation augmentation systems
GUO Shuren, LIU Cheng, GAO Weiguang, LU Jun
2019, 44(2): 1-12.   doi: DOI:10.13442/j.gnss.1008-9268.2019.02.001
[Abstract](2333) [PDF 1536KB](1309)
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  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](1847) [PDF 1895KB](361)
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Accuracy analysis of BDS-2/BDS-3 standard point positioning
FANG Xinqi, FAN Lei
2020, 45(1): 19-25.   doi: DOI:10.13442/j.gnss.1008-9268.2020.01.003
[Abstract](1078) [PDF 750KB](217)
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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](1642) [PDF 93258KB](335)
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Positioning Performance Comparison and Analysis on BDS Dual and Triple Frequency Static Precise Point Positioning
2017, 42(1): 53-58.   doi: 10.13442/j.gnss.1008-9268.2017.01.011
[Abstract](838) [PDF 678KB](170)
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A Survey of Fusion Algorithms for Multi-source Navigation Fusion System
TANG Luyang, TANG Xiaomei, LI Baiyu, LIU Xiaohui
2018, 43(3): 39-44.   doi: 10.13442/j.gnss.1008-9268.2018.03.007
[Abstract](849) [PDF 668KB](199)
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Effect of image control point layout on the accuracy of real-world modeling of small-scale irregular areas of UAVs
ZHANG Guangzu, WANG Chun, XU Yan, TAO Yu, WU Liang, SHENG Shuai
2020, 45(2): 60-67.   doi: DOI:10.13442/j.gnss.1008-9268.2020.02.010
[Abstract](296) [PDF 2013KB](86)
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High Precision GPS/BDS Data Processing and Precision Contrast Analysis Based on GAMIT10.61
LIU Xingwei, PU Dexiang, GAO Xiang, ZHANG Shiyong, XIA Dinghui
2018, 43(5): 77-83.   doi: 10.13442/j.gnss.1008-9268.2018.05.015
[Abstract](995) [PDF 648KB](228)
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A New Method of NMEA0813 Protocol Parsing
LIU Fushan, GUO Chengjun, JIA Zhendong
2017, 42(1): 70-73.   doi: 10.13442/j.gnss.1008-9268.2017.01.014
[Abstract](845) [PDF 476KB](155)
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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](1143) [PDF 1830KB](189)
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Construction and development of satellite navigation augmentation systems
GUO Shuren, LIU Cheng, GAO Weiguang, LU Jun
2019, 44(2): 1-12.   doi: DOI:10.13442/j.gnss.1008-9268.2019.02.001
[Abstract](2333) [PDF 1536KB](345)
Abstract:
Since the birth of satellite navigation system, a variety of enhancement technologies and means are developed, and a large number of enhancement systems are established to meet the needs of users with higher accuracy and integrity. However, as a matter of fact, they are generated  later than the basic system and built independently on the respective demands, there are problems of “fragmentation” and “patch”  development, functional overlap with each other, lack of unified planning and standards, and unsystematic construction. This paper reviews and summarizes the generation and development process of satellite navigation augmentation technology, combings the relevant technical connotation and definition, and focuses on the related construction and development of China BeiDou Satellite navigation system augmentation system. On this basis, combined with emerging technologies such as 5G communication and loworbit satellites, the future development of satellite navigation augmentation system is prospected and analyzed.  Finally, suggestions are made for the augmentation system construction of the future BeiDou positioning, navigation and timing (PNT) comprehensive service.
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](1888) [PDF 62945KB](221)
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.

Fog positioning and its applications
SHI Chuang, GU Shengfeng, JING Guifei, GENG Jianghui, LOU Yidong, TANG Weiming
2019, 44(5): 1-9.   doi: DOI:10.13442/j.gnss.1008-9268.2019.05.001
[Abstract](1610) [PDF 1146KB](189)
Abstract:
With the development of GNSS, the LBS (Location Based Service) has been popularized rapidly. Meanwhile, people’s demand for PNT service with high reliability, high credibility and high precision is increasingly urgent. PNT is a system which integrates multi-technology and multilevel systems. Focusing on the optimization of PNT service, domestic and overseas scholars have put forward several new architectures and technical systems such as All Source Positioning and Navigation, Resilient PNT and Cloud Positioning. This study states, that with heterogeneous positioning resources which are capable in communication, calculation, storing, positioning and sensing as infrastructure construction, PNT service with high reliability, high credibility and high precision can be realized by intelligent management and scheduling of heterogeneous positioning resources distributed in different geolocations. Further, the definitions of Fog Positioning and Omnipresent Positioning and Navigation are given. It is argued that the definition of Fog Positioning is evolved from distributed computing architecture and emphasizes the architecture for PNT service. While the definition of Omnipresent Positioning and Navigation is evolved from the development of positioning technology and emphasizes the ability to realize omnipresent positioning by collaborative fusion processing of omnipresent positioning resources. On this basis, by comparing Fog Positioning with Cloud Positioning, this study points out that Fog Positioning is the extension of Cloud Positioning towards the user side and the omnipresent realization of positioning resources. Meanwhile, Fog Positioning is one kind of dynamic and elastic cloud, so Fog Positioning can be seen as a PNT architecture with the property of elasticity. Omnipresent positioning is an important target of PNT architecture, and Fog Positioning gives the potential means for this target, e.g., Omnipresent Positioning and Navigation. At last, this contribution analysis the basic service mode for Fog Positioning or Omnipresent Positioning and Navigation under the city environment and indoor environment.
A novel engineering implementation technique for acquiring B1C signal in the BeiDou-3 receiver
YAN Shulin, DING Chao
2019, 44(1): 1-9.   doi: DOI:10.13442/j.gnss.1008-9268.2019.01.001
[Abstract](1502) [PDF 1077KB](160)
Abstract:
The modern signals of the Chinese BeiDou-3 navigation system bring new features compared to the previous civilian signals, such as longer spreading code, involving secondary code, new modulation technique (i.e. Binary Offset Carrier BOC), data/pilot channels and so on. These innovations are able to enhance the signal acquisition robustness, but they also require specific acquisition techniques to handle the large data stream, deal with the problem of sign transition and side peaks caused by the secondary code and the BOC modulation respectively. This paper proposes a novel two-stage acquisition technique for realizing efficient acquisition of the B1C signal in the engineering implementation of the modern receiver. The first stage employs an extended parallelized Averaging Correlation (AC) search structure, which can cope with the sign transition problem, to coarsely capture the signal with high efficiency. At the second stage, a fine-search process is completed within a reduced searching range to provide high precision result. The involving of the later stage aims to avoid the side peaks effect in the tracking stage that can easily cause a false lock. In addition, both of the single and channel combining acquisition techniques are introduced, which give designers an option of implementing the acquisition with higher sensitivity but more resources. The experiment results demonstrate that the proposed method allows to use much cheaper FFT blocks and enables fast acquisition by parallel process. The proposed method can reduce the number of multiplications by at least 61% when the sampling frequency is over 50 MHz while providing quite similar acquisition precisions with the conventional method.
  Research Progress and Prospect of PPP/INS Integration System
WANG Haoyuan, SUN Fuping, XIAO Kai
2017, 42(5): 53-58.   doi: 10.13442/j.gnss.1008-9268.2017.05.011
[Abstract](1727) [PDF 778KB](208)
Abstract:
With the construction of GNSS multi-system, precise point positioning (PPP) technology is developing in the direction of real-time and ambiguity-fixed solution. The PPP/INS integration system has a wide application prospect in the navigation and surveying field, since the convenience of not laying base station. In this paper, the contributions of GNSS multi-system, PPP ambiguity fixing, INS-aided to the PPP/INS integration system are systematically summarized. And the progresses of filtering method, smoothing algorithm and stochastic model establishment in integration system are generalized. The development trend of the PPP/INS integration system is discussed.

Bimonthly, Established 1976

Sponsored by:China Institute of Radio Transmission

Competent Authorities:China Electronics Technology Group Corporation

ISSN 1008-9268

CN 41-1317/TN