BDSec:Security Authentication Protocol for BeiDou-Ⅱ Civil Navigation Message

Due to the lack of authentication mechanism in BeiDou navigation satellite system(BDS),BD-Ⅱ civil navigation message(BDⅡ-CNAV) are vulnerable to spoofing attack and replay attack.To solve this problem,we present a security authentication protocol,called as BDSec,which is designed by using China’s cryptography Shangyong Mima(SM) series algorithms,such as SM2/4/9 and Zu Chongzhi(ZUC)algorithm.In BDSec protocol,both of BDⅡ-CNAV and signature information are encrypted using the SM4 algorithm(Symmetric encryption mechanism).The encrypted result is used as the subject authentication information.BDSec protocol applies SM9 algorithm(Identity-based cryptography mechanism) to protect the integrity of the BDⅡ-CNAV,adopts the SM2 algorithm(Public key cryptosystem) to guarantee the confidentiality of the important session information,and uses the ZUC algorithm(Encryption and integrity algorithm) to verify the integrity of the message authentication serial number and initial information and the information in authentication initialization sub-protocol respectively.The results of the SVO logic reasoning and performance analysis show that BDSec protocol meets security requirements for the dual user identity authentication in BDS and can realize the security authentication of BDⅡ-CNAV.

Data-Driven Heuristic Assisted Memetic Algorithm for Efficient Inter-Satellite Link Scheduling in the BeiDou Navigation Satellite System

Inter-satellite link(ISL)scheduling is required by the BeiDou Navigation Satellite System(BDS)to guarantee the system ranging and communication performance.In the BDS,a great number of ISL scheduling instances must be addressed every day,which will certainly spend a lot of time via normal metaheuristics and hardly meet the quick-response requirements that often occur in real-world applications.To address the dual requirements of normal and quick-response ISL schedulings,a data-driven heuristic assisted memetic algorithm(DHMA)is proposed in this paper,which includes a high-performance memetic algorithm(MA)and a data-driven heuristic.In normal situations,the high-performance MA that hybridizes parallelism,competition,and evolution strategies is performed for high-quality ISL scheduling solutions over time.When in quick-response situations,the data-driven heuristic is performed to quickly schedule high-probability ISLs according to a prediction model,which is trained from the high-quality MA solutions.The main idea of the DHMA is to address normal and quick-response schedulings separately,while high-quality normal scheduling data are trained for quick-response use.In addition,this paper also presents an easy-to-understand ISL scheduling model and its NP-completeness.A seven-day experimental study with 10080 one-minute ISL scheduling instances shows the efficient performance of the DHMA in addressing the ISL scheduling in normal(in 84 hours)and quick-response(in 0.62 hour)situations,which can well meet the dual scheduling requirements in real-world BDS applications.

Application and Prospect of BeiDou Navigation Satellite System in the Transportation Industry

The transportation industry is one of the largest users of the BeiDou Navigation Satellite System(BDS),characterized by multiple locations,long lines,wide range,and extensive mobility.The application of BDS in the transportation industry improves the development level of intelligent,safe,green and shared transportation.Based on the introduction of the application requirements and characteristics of BDS in the transportation industry,this paper systematically introduces the overall status of BDS in the transportation industry,covering highways,waterways,railways,civil aviation,and the postal service.Finally,the paper forecasts future applications of BDS in the field of transportation.It identifies within the transportation industry rich application scenarios for the cultivation of advanced technologies represented by BDS,enhancing transportation safety services and guaranteeing emergency communication,while improving the operation efficiency and management level of an integrated transportation system.

BeiDou Regional Navigation Satellite System Completed

As the 16th BeiDou navigation satellite was successfully launched into space at 23:33 Beijing Time from the Xichang Satellite Launch Center (XSLC) on October 25, 2012, China completed the construction of the BeiDou Regional Navigation Satellite System that starts to officially provide services for most parts of the Asia-Pacific region from December 27. The 16th BeiDou navigation satellite, the last one for the regional BeiDou system, was developed by China Academy of Space Technology under CASC.

Networking of BeiDou Navigation Satellite System Accelerated with Two New Members

At 4:50 on April 30, China's LM-3B/I rocket, an improved type based on LM-3B, made its debut at the Xichang Satellite Launch Center and successfully sending the 12th and 13th BeiDou Navigation Satellite System satellites into the planned transfer orbit in space. It was the first time that China launched two BeiDou satellites with one rocket. It was

China Launches the 11th BeiDou Satellite in Navigation Satellite System

China launched the 11th BeiDou navigation satellite in their BeiDou Navigation Satellite System.The satellite was launched from the Xichang Satellite Launch Center in Sichuan Province on a LM-3C rocket at 0:12 on February 25 (Beijing time) and was put into the predetermined transfer orbit successfully.The geostationary satellite is the first BeiDou navigation satellite launched in 2012 for the

TESLA-Based Authentication for BeiDou Civil Navigation Message

Due to the civil BeiDou navigation system is open,unauthenticated,and non-encrypted,civilian BeiDou navigation signals may have great security loopholes during transmission or reception.The main security loophole here is spoofing attacks.Spoofing attacks make the positioning or timing results of BeiDou civilian receivers wrong.Such errors may cause a series of security problems,which lays a serious hidden danger for Bei-Dou satellite information security.This article proposes an anti-spoofing method for BeiDou navigation system based on the combination of SM commercial cryptographic algorithm and Timed Efficient Stream Loss-tolerant Authentication(TESLA)for spoofing attacks.In this solution,we use the SM3 algorithm to generate a TESLA key chain with time information,and then use the key in the key chain to generate the message authentication code for the BeiDou D2 navigation message.The message authentication code is inserted into a reserved bit of the D2 navigation message.In addition,this solution uses the SM2 algorithm to protect and encrypt time information in the TESLA key chain to prevent key replay attacks in TESLA.The experimental results tested on the experimental platform built in this paper show that this scheme reduces the possibility of the BeiDou navigation system being deceived and enhances the safety of the BeiDou navigation system.

Research on Blanket Jamming to Beidou Navigation Signals Based on BOC Modulation

Aiming at the issue of influence of blanket jamming on performances of Beidou navigation signals, through studying Beidou signals based on the BOC modulation technology, establishing a blanket jamming mathematical model, and performing modeling and simulation on multiple jamming technologies, to attain the jamming curves of time domains and frequency domains of Beidou signals, and the correlation curve of the signal-to-jamming rate and the bit error rate under blanket jamming, and thus realizing evaluation on the jamming performance.

The 10th BeiDou 2 Navigation Satellite Flew into Space

LM launch vehicles established a new record by successfully performing the 16th successful flight this year.A LM-3A launched the 10th BeiDou 2 satellite into its predetermined transfer orbit on December 2 from the XSLC in Sichuan Province.

Control Policy Learning Design for Vehicle Urban Positioning via BeiDou Navigation

This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou navigation.While navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou signal.Here,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback control.The proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle dynamics.It is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.

BeiDou Integrated Disaster Reduction Application Platform

To better improve the emergency communication and location-based services of disaster information reporting network for serious natural response and relieL disaster emergency the national natural disaster reduction application platform based on BeiDou navigation satellite system is constructed. The administrative distributed platform is integrated with BeiDou positioning and multiple communication ways so as to achieve main disaster reduction application services, including disaster information acquisition and monitoring, emergency relief for trapped people, on-site emergency relief command service, relief supplies＇ transportation monitoring, and disaster information publishing service. By the platform, serious disaster information reporting time may be reduced to one hour and the emergency decision-making information service for serious natural disasters can be effectively improved, and it will be helpful to provide technical references for the industrial application and promotion of BeiDou inte- grated disaster reduction.

Modeling and Prediction of Inter-System Bias for GPS/BDS-2/BDS-3 Combined Precision Point Positioning

The combination of Precision Point Positioning(PPP)with Multi-Global Navigation Satellite System(MultiGNSS),called MGPPP,can improve the positioning precision and shorten the convergence time more effectively than the combination of PPP with only the BeiDou Navigation Satellite System(BDS).However,the Inter-System Bias(ISB)measurement of Multi-GNSS,including the time system offset,the coordinate system difference,and the inter-system hardware delay bias,must be considered for Multi-GNSS data fusion processing.The detected ISB can be well modeled and predicted by using a quadratic model(QM),an autoregressive integrated moving average model(ARIMA),as well as the sliding window strategy(SW).In this study,the experimental results indicate that there is no apparent difference in the ISB between BDS-2 and BDS-3 observations if B1I/B3I signals are used.However,an obvious difference in ISB can be found between BDS-2 and BDS-3 observations if B1I/B3I and B1C/B2a signals are used.Meanwhile,the precision of the Predicted ISB(PISB)on the next day of all stations is about 0.1−0.6 ns.Besides,to effectively utilize the PISB,a new strategy for predicting the PISB for MGPPP is proposed.In the proposed strategy,the PISB is used by adding two virtual observation equations,and an adaptive factor is adopted to balance the contribution of the Observed ISB(OISB)and the PISB to the final estimations of ISB.To validate the effectiveness of the proposed method,some experimental schemes are designed and tested under different satellite availability conditions.The results indicate that in open sky environment,the selective utilization of the PISB achieves almost the same positioning precision of MGPPP as the direct utilization of the PISB,but the convergence time of MGPPP is reduced by 7.1%at most in the north(N),east(E),and up(U)components.In the blocked sky environment,the selective utilization of the PISB contributes to more significant improvement of the positioning precision and convergence time than that in the open sky environment.Compared with the direct utilization of the PISB,the selective utilization of the PISB improves the positioning precision and convergence time by 6.7%and 12.7%at most in the N,E,and U components,respectively.

Preliminary assessment of the navigation and positioning performance of BeiDou regional navigation satellite system

BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satellites in Inclined Geosynchronous Orbit （IGSO）, and 4 satellites in Medium Earth Orbit （MEO）. In this paper, its basic navigation and positioning performance are evaluated preliminarily by the real data collected in Beijing, including satellite visibility, Position Dilution of Precision （PDOP） value, the precision of code and carrier phase measurements, the accuracy of single point positioning and differential position- ing and ambiguity resolution （AR） performance, which are also compared with those of GPS. It is shown that the precision of BDS code and carrier phase measurements are about 33 cm and 2 mm, respectively, which are comparable to those of GPS, and the accuracy of BDS single point positioning has satisfied the design requirement. The real-time kinematic positioning is also feasible by BDS alolae in the opening condition, since its fixed rate and reliability of single-epoch dual-frequency AR is comparable to those of GPS. The accuracy of BDS carrier phase differential positioning is better than 1 cm for a very short baseline of 4.2 m and 3 cm for a short baseline of 8.2 km, which is on the same level with that of GPS. For the combined BDS and GPS, the fixed rate and reliability of single-epoch AR and the positioning accuracy are improved significantly. The accu- racy of BDS/GPS carrier phase differential positioning is about 35 and 20 % better than that of GPS for two short baseline tests in this study. The accuracy of BDS code differential positioning is better than 2.5 m. However it is worse than that of GPS, which may result from large code multipath errors of BDS GEO satellite measurements.

Application of BeiDou navigation satellite system in emergency rescue of natural hazards: a case study for field geological survey of Qinghai−Tibet plateau

In recent years,geological and mineral resources exploration in China has expanded to deep hinterland of the Qinghai−Tibet Plateau and other regions with complex geological conditions.The special natural conditions of Qinghai−Tibet Plateau determine the characteristics of“life-forbidden zone”that is characterized by alpine hypoxia,changeable weather,complex road conditions,and beast attack.In particular,the work in wild depopulated zones with severe environment and poor communications imposes serious threats to the life safety of geological personnel.Therefore,how to guarantee the safety of geological personnel working on the Qinghai−Tibet Plateau and how to reduce or even avoid casualty of geological personnel have currently become the urgent challenge.In this study,an emergency rescue information system for field geological survey is constructed based on BeiDou Navigation Satellite System.A case study of emergency rescue has been conducted in the depopulated zone of the Qinghai−Tibet Plateau and good effects have been achieved,providing security assurance for personnel engaged in field geological survey on the Qinghai−Tibet Plateau and technical support for the emergency rescue in case of natural hazards on the Qinghai−Tibet Plateau.The BeiDou Navigation Satellite System(BDS)can be effectively used to locate and communicate in the emergency rescue for rigorous Geological survey task where there is no network signal for the mobile phone,and the emergency rescue guarantee system is independent,reliable,and relatively cheap.The application value of BDS is demonstrated in the geological field.

Advances in BeiDou Navigation Satellite System(BDS)and satellite navigation augmentation technologies

Several noteworthy breakthroughs have been made with the BeiDou Navigation Satellite System(BDS)and other global navigation satellite systems as well as the associated augmentation systems,such as the commissioning of the BDS-3 preliminary system and the successful launch of the first BDS-3 GEO satellite which carries the satellite-based augmentation payload.Presently,BDS can provide basic services globally,and its augmentation system is also being tested.This paper gives an overview of BDS and satellite navigation augmentation technologies.This overview is divided into four parts,which include the system segment technologies,satellite segment technologies,propagation segment technologies,and user segment technologies.In each part,these technologies are described from the perspectives of preliminary information,research progress,and summary.Moreover,the significance and progress of the BeiDou Satellite-based Augmentation System(BDSBAS),low earth orbit augmentation,and the national BeiDou ground-based augmentation system are presented,along with the airborne-based augmentation system.Furthermore,the conclusions and discussions covering popular topics for research,frontiers in research and development,achievements,and suggestions are listed for future research.

Initial analysis for characterizing and mitigating the pseudorange biases of BeiDou navigation satellite system

Pseudorange bias has become a practical obstacle in the field of high-precision global navigation satellite system(GNSS)applications,which greatly restricts the further development of high-precision applications.Unfortunately,no studies have been conducted on the pseudorange biases of the BeiDou navigation satellite system(BDS).To mitigate the effects of pseudorange biases on the BDS performance to the greatest extent possible,the origin of such BDS pseudorange biases are first thoroughly illustrated,based upon which the dependency of the biases on the receiver configurations are studied in detail.Owing to the limitations regarding the parameter re-settings for hardware receivers,software receiver technology was used to achieve the ergodicity of the receiver parameters,such as the correlator spacing and front-end bandwidth,using high-fidelity signal observations collected by a 40-m-high gain dish antenna at Haoping Observatory.Based on this,the pseudorange biases of the BDS B1I and B3I signals and their dependency on different correlator spacings and front-end bandwidths were adequately provided.Finally,herein,the suggested settings of the correlator spacing and front-end bandwidth for BDS receivers are in detail proposed for the first time.As a result,the pseudorange biases of the BDS signals will be less than 20 cm,reaching even under 10 cm,under this condition.This study will provide special attention to GNSS pseudorange biases,and will significantly promote a clear definition of the appropriate receiver parameter settings in the interface control documents of BDS and other individual satellite systems.

Building an“Outer Space Silk Road”:China’s Beidou Navigation Satellite System in the Arab World

Navigation satellite systems are the symbols of states’hard power,and so are the assets of science and technology diplomacy.In the new era,the structure of great powers’navigation satellite systems is characterized by“one superpower”(the US GPS),“multi-pillars”(EU’s Galileo,Russian GLONASS and Chinese Beidou),and“multi-centers”(Indian regional navigation satellite system and Japanese quasi zenith navigation satellite system).Beidou is of great significance to promoting“One Belt and One Road”Initiative in the Arab world,and the essential measures to deepen the strategic partnership between China and the Arab League in inter-connectivity;it will also be an essential step for Beidou’s“going global”strategy in the long run.The implementation of Beidou’s projects in the Arab world is confronted with four dimensions of challenges of political,security,judicial and socio-cultural risks.Its implementation follows an incremental principle,choose pivotal states,create a radiation effect,which will lay a foundation for Beidou to open the West Asian and African market in the years to come.

Monitoring the ionosphere based on the Crustal Movement Observation Network of China

The Global Navigation Satellite System （GNSS） is becoming important for monitoring the variations in the earth＇s ionosphere based on the total electron content （TEC） and iono- spheric electron density （IED）. The Crustal Movement Observation Network of China （CMONOC）, which includes GNSS stations across China's Mainland, enables the continuous monitoring of the ionosphere over China as accurately as possible. A series of approaches for GNSS-based ionospheric remote sensing and software has been proposed and devel- oped by the Institute of Geodesy and Geophysics （IGG） in Wuhan. Related achievements include the retrieval of ionospheric observables from raw GNSS data, differential code biases estimations in satellites and receivers, models of local and regional ionospheric TEC, and algorithms of ionospheric tomography. Based on these achievements, a software for processing GNSS data to determine the variations in ionospheric TEC and IED over China has been designed and developed by IGG. This software has also been installed at the CMONOC data centers belonging to the China Earthquake Administration and China Meteorological Administration. This paper briefly introduces the related research achievements and indicates potential directions of future work.

Time synchronization in communication networks based on the Beidou foundation enhancement system

Communication networks rely on time synchronization information generated by base station equipment(either the Global Navigation Satellite System receiver or rubidium atomic clock) to enable wireless networking and communications. Meanwhile, the time synchronization among base stations depends on the Network Time Protocol. With the development of mobile communication systems, the corresponding time synchronization accuracy has increased as well. In this case, the use of sparsely distributed-high-precision synchronization points to synchronize time for an entire network with high precision is a key problem and is the foundation of the enhanced network communication. The current receiver equipment for China's digital synchronous network typically includes dedicated multi-channel GPS receivers for communication; however, with the development of GPS by the USA, network security has been destabilized and reliability is low. Nonetheless, network time synchronization based on Beidou satellite navigation system timing devices is an inevitable development trend for China's digital communications network with the establishment of the independently developed BDS, especially the implementation and improvement of the Beidou foundation enhancement system.

A GPS/BDS dual-mode positioning algorithm for a train based on CIPSO_EKF

When using global positioning system/BeiDou navigation satellite(GPS/BDS)dual-mode navigation system to locate a train,Kalman filter that is used to calculate train position has to be adjusted according to the features of the dual-mode observation.Due to multipath effect,positioning accuracy of present Kalman filter algorithm is really low.To solve this problem,a chaotic immune-vaccine particle swarm optimization_extended Kalman filter(CIPSO_EKF)algorithm is proposed to improve the output accuracy of the Kalman filter.By chaotic mapping and immunization,the particle swarm algorithm is first optimized,and then the optimized particle swarm algorithm is used to optimize the observation error covariance matrix.The optimal parameters are provided to the EKF,which can effectively reduce the impact of the observation value oscillation caused by multipath effect on positioning accuracy.At the same time,the train positioning results of EKF and CIPSO_EKF algorithms are compared.The eastward position errors and velocity errors show that CIPSO_EKF algorithm has faster convergence speed and higher real-time performance,which can effectively suppress interference and improve positioning accuracy.