Assessment of Radio Frequency Compatibility between Compass Phase II and Other GNSSs

2011 ◽  
Vol 64 (S1) ◽  
pp. S55-S72 ◽  
Author(s):  
Li Liu ◽  
Xingqun Zhan ◽  
Wei Liu ◽  
Mancang Niu
Keyword(s):  
Radio Frequency ◽  
Phase Ii ◽  
Density Ratio ◽  
Critical Issue ◽  
Satellite System ◽  
Asia Pacific ◽  
Separation Coefficient ◽  
Interference Level ◽  
Wide Area Augmentation System ◽  
Global Navigation Satellite

As the technology of global navigation satellite system (GNSS) and augmentation systems are evolving rapidly, compatibility becomes a critical issue for system providers. By April 2011, China had successfully launched eight satellites of the Compass phase II (CP II) navigation system, which will provide positioning, navigation, timing and communication services to the Asia-Pacific region by the year 2012. Due to the limitations of available radio frequency bandwidths, it is important to assess the compatibility and to design signals based on the compatibility within these limited radio frequency bandwidths. This paper presents a modified compatibility assessment methodology, derived from the traditional methodologies that are based on the spectral separation coefficient (SSC) and the effective carrier-power-to-noise density ratio. The modified methodology takes into account additional factors including the Doppler offset, code tracking loop, and band-limiting, sampling and quantisation (BSQ) of the GNSS receiver. In the simulation section, the comprehensive compatibility assessment between CP II and other GNSSs, such as GPS, Galileo, Wide Area Augmentation System (WAAS) and European Geostationary Navigation Overlay Service (EGNOS) on L1 Band are carried out and presented with some new results. Simulation results reveal that CP II does not cause serious interference on GPS, Galileo, WAAS and EGNOS as the interference level is below the 0·25 dB threshold recommended by ITU.

Assessment of Radio Frequency Compatibility Relevant to the Galileo E1/E6 and Compass B1/B3 Bands

2010 ◽  
Vol 63 (3) ◽  
pp. 419-434 ◽  
Author(s):  
Wei Liu ◽  
Gang Du ◽  
Xingqun Zhan ◽  
Chuanrun Zhai
Keyword(s):  
Radio Frequency ◽  
Sensitivity Coefficient ◽  
Satellite System ◽  
Separation Coefficient ◽  
Interference Effects ◽  
Code Tracking ◽  
The Earth ◽  
Spectral Separation ◽  
User Communities ◽  
Global Navigation Satellite

The intersystem interference between Galileo and Compass, known as a radio frequency compatibility problem, has become a matter of great concern for the system providers and user communities. This paper firstly describes two fundamentally different methods to assess the Global Navigation Satellite System (GNSS) intersystem interference, by using different interference coefficients that are calculated for each combination of signals: the spectral separation coefficient (SSC) and code tracking spectral sensitivity coefficient (CT_SSC). And then a complete methodology combining the SSC and CT_SSC is presented. Real simulations are carried out to assess the interference effects where Galileo and Compass signals are sharing the same band (E1/B1 and E6/B3 bands) at every time and place on the Earth. Simulation results show that the effects of intersystem interference are significantly different by using these two methodologies. It is also shown that the Compass system leads to intersystem interference on Galileo but that the maximal values are lower than Galileo interference to Compass. The design and implementation of any new signal has to be conducted carefully in order for there to be radio frequency compatibility.

scholarly journals Design of a Multiband Global Navigation Satellite System Radio Frequency Interference Monitoring Front-End with Synchronized Secondary Sensors

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2594
Author(s):  
Aiden Morrison ◽  
Nadezda Sokolova ◽  
James Curran
Keyword(s):  
Radio Frequency ◽  
Global Navigation Satellite System ◽  
Low Cost ◽  
Satellite System ◽  
Radio Frequency Interference ◽  
Navigation Satellite ◽  
Inertial Measurement ◽  
Front End ◽  
Global Navigation ◽  
Global Navigation Satellite

This paper investigates the challenges of developing a multi-frequency radio frequency interference (RFI) monitoring and characterization system that is optimized for ease of deployment and operation as well as low per unit cost. To achieve this, we explore the design and development of a multiband global navigation satellite system (GNSS) front-end which is intrinsically capable of synchronizing side channel information from non-RF sensors, such as inertial measurement units and integrated power meters, to allow the simultaneous production of substantial amounts of sampled spectrum while also allowing low-cost, real-time monitoring and logging of detected RFI events. While the inertial measurement unit and barometer are not used in the RFI investigation discussed, the design features that provide for their precise synchronization with the RF sample stream are presented as design elements worth consideration. The designed system, referred to as Four Independent Tuners with Data-packing (FITWD), was utilized in a data collection campaign over multiple European and Scandinavian countries in support of the determination of the relative occurrence rates of L1/E1 and L5/E5a interference events and intensities where it proved itself a successful alternative to larger and more expensive commercial solutions. The dual conclusions reached were that it was possible to develop a compact low-cost, multi-channel radio frequency (RF) front-end that implicitly supported external data source synchronization, and that such monitoring systems or similar capabilities integrated within receivers are likely to be needed in the future due to the increasing occurrence rates of GNSS RFI events.

scholarly journals A Joint Dual-Frequency GNSS/SINS Deep-Coupled Navigation System for Polar Navigation

2018 ◽  
Vol 8 (11) ◽  
pp. 2322 ◽  
Author(s):  
Lin Zhao ◽  
Mouyan Wu ◽  
Jicheng Ding ◽  
Yingyao Kang
Keyword(s):  
Navigation System ◽  
Density Ratio ◽  
Satellite System ◽  
The Arctic ◽  
Observation Data ◽  
Dual Frequency ◽  
Vector Tracking ◽  
Time Observation ◽  
Global Navigation Satellite ◽  
Navigation Accuracy

The strategic position of the polar area and its rich natural resources are becoming increasingly important, while the northeast and northwest passages through the Arctic are receiving much attention as glaciers continue to melt. The global navigation satellite system (GNSS) can provide real-time observation data for the polar areas, but may suffer low elevation problems of satellites, signals with poor carrier-power-to-noise-density ratio (C/N0), ionospheric scintillations, and dynamic requirements. In order to improve the navigation performance in polar areas, a deep-coupled navigation system with dual-frequency GNSS and a grid strapdown inertial navigation system (SINS) is proposed in the paper. The coverage and visibility of the GNSS constellation in polar areas are briefly reviewed firstly. Then, the joint dual-frequency vector tracking architecture of GNSS is designed with the aid of grid SINS information, which can optimize the tracking band, sharing tracking information to aid weak signal channels with strong signal channels and meet the dynamic requirement to improve the accuracy and robustness of the system. Besides this, the ionosphere-free combination of global positioning system (GPS) L1 C/A and L2 signals is used in the proposed system to further reduce ionospheric influence. Finally, the performance of the system is tested using a hardware simulator and semiphysical experiments. Experimental results indicate that the proposed system can obtain a better navigation accuracy and robust performance in polar areas.

scholarly journals First results of BDS positioning for LBS applications in the UK

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Yan Xia ◽  
Xiaolin Meng ◽  
Yusong Yang ◽  
Shuguo Pan ◽  
Qing Zhao ◽  
...  
Keyword(s):  
Density Ratio ◽  
Satellite System ◽  
Location Based Services ◽  
Navigation Satellite ◽  
Location Services ◽  
First Results ◽  
Global Coverage ◽  
The Uk ◽  
Global Navigation Satellite ◽  
Good Visibility

AbstractThe last satellite of BeiDou Navigation Satellite System with Global Coverage (BDS-3) constellation was successfully launched on June 23rd, 2020, and the entire system began to provide Positioning, Navigation, and Timing (PNT) services worldwide. We evaluated the performance of location services using BDS with a smartphone that can track the Global Navigation Satellite System (GNSS) satellites in Nottingham, UK. The static and kinematic experiments were conducted in an open meadow and a lakeside route covered by trees, respectively. Experimental results show that BDS has good visibility, and its overall signal carrier-to-noise density ratio (C/N0) is comparable to that of Global Positioning System (GPS). The average C/N0 of BDS-3 satellites with elevation angles above 45° on B1 band is the highest among all systems, reaching 40.0 dB·Hz. The noise level of the BDS pseudorange measurements is within 0.5 m, and it has a good consistency among satellites. In the static experiment, the standard deviations of BDS positioning in the east, north and up directions are 1.09, 1.16, and 3.02 m, respectively, and the R95 value of the horizontal position is 2.88 m. In harsh environments, the number of BDS satellites tracked by the smartphone is susceptible to environmental factors. The bias Root Mean Squares (RMS) in the three directions of the whole kinematic positioning are 6.83, 6.68, 11.67 m, in which the positioning bias RMS values in a semi-open environment are only 2.81, 1.11, 3.29 m. Furthermore, the inclusion of BDS in multiple GNSS systems can significantly improve the positioning precision. This study intends to provide a reference for the further improvements of BDS global PNT services, particularly for Location-Based Services (LBS).

Performance analysis of BDS/GPS kinematic vehicle positioning in various observation conditions

Sensor Review ◽  
2016 ◽  
Vol 36 (3) ◽  
pp. 249-256 ◽  
Author(s):  
Xin Li ◽  
Jiming Guo ◽  
Lv Zhou
Keyword(s):  
Urban Area ◽  
Satellite System ◽  
Asia Pacific ◽  
Navigation Satellite ◽  
Content Type ◽  
Kinematic Positioning ◽  
Constrained Environments ◽  
Regional Service ◽  
Vehicle Positioning ◽  
Global Navigation Satellite

Purpose Global positioning system (GPS) kinematic positioning suffers from performance degradation in constrained environments such as urban canyons, which then restricts the application of high-precision vehicle positioning and navigation within the city. In December 2012, the BeiDou Navigation Satellite System (BDS) regional service was announced, and the combined BDS/GPS kinematic positioning has been enabled in the Asia-Pacific area. Previous studies have mainly focused on the performance evaluations of combined BDS/GPS static positioning. Not much work has been performed for kinematic vehicle positioning under constrained observation conditions. This study aims to analyze the performance of BDS/GPS kinematic vehicle positioning in various conditions. Design/methodology/approach In this study, three vehicle experiments under three observation conditions, an open suburban area, a less dense non-central urban area and a dense central urban area, are investigated using both the code-based differential global navigation satellite system (DGNSS) and phase-based real-time kinematic (RTK) modes. The comparison between combined BDS/GPS and GPS-only vehicle positioning solutions is conducted in terms of positioning availability and positioning precision. Findings Numerical results show that the combined BDS/GPS system significantly outperforms the GPS-only system under poor observation conditions, whereas the improvement was less significant under good observation conditions. Originality/value Thus, this paper studies the performance of combined BDS/GPS kinematic relative positioning under various observation conditions.

scholarly journals Precise Orbit Determination for BeiDou GEO/IGSO Satellites during Orbit Maneuvering with Pseudo-Stochastic Pulses

2019 ◽  
Vol 11 (21) ◽  
pp. 2587
Author(s):  
Qin ◽  
Huang ◽  
Zhang ◽  
Wang ◽  
Yan ◽  
...  
Keyword(s):  
Orbit Determination ◽  
Precise Orbit Determination ◽  
Satellite System ◽  
Assessment System ◽  
Asia Pacific ◽  
Earth Orbit ◽  
Observation Data ◽  
Navigation Satellite ◽  
Precise Orbit ◽  
Global Navigation Satellite

In order to provide better service for the Asia-Pacific region, the BeiDou navigation satellite system (BDS) is designed as a constellation containing medium earth orbit (MEO), geostationary earth orbit (GEO), and inclined geosynchronous orbit (IGSO). However, the multi-orbit configuration brings great challenges for orbit determination. When orbit maneuvering, the orbital elements of the maneuvered satellites from broadcast ephemeris are unusable for several hours, which makes it difficult to estimate the initial orbit in the process of precise orbit determination. In addition, the maneuvered force information is unknown, which brings systematic orbit integral errors. In order to avoid these errors, observation data are removed from the iterative adjustment. For the above reasons, the precise orbit products of maneuvered satellites are missing from IGS (international GNSS (Global Navigation Satellite System) service) and iGMAS (international GNSS monitoring and assessment system). This study proposes a method to determine the precise orbits of maneuvered satellites for BeiDou GEO and IGSO. The initial orbits of maneuvered satellites could be backward forecasted according to the precise orbit products. The systematic errors caused by unmodeled maneuvered force are absorbed by estimated pseudo-stochastic pulses. The proposed method for determining the precise orbits of maneuvered satellites is validated by analyzing data of stations from the Multi-GNSS Experiment (MGEX). The results show that the precise orbits of maneuvered satellites can be estimated correctly when orbit maneuvering, which could supplement the precise products from the analysis centers of IGS and iGMAS. It can significantly improve the integrality and continuity of the precise products and subsequently provide better precise products for users.

scholarly journals BeiDou Augmented Navigation from Low Earth Orbit Satellites

Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 198 ◽  
Author(s):  
Mudan Su ◽  
Xing Su ◽  
Qile Zhao ◽  
Jingnan Liu
Keyword(s):  
Simulated Data ◽  
Slow Motion ◽  
Satellite System ◽  
Low Earth Orbit ◽  
Convergence Time ◽  
Asia Pacific ◽  
Earth Orbit ◽  
Navigation Satellite ◽  
Beidou Navigation Satellite System ◽  
Global Navigation Satellite

Currently, the Global Navigation Satellite System (GNSS) mainly uses the satellites in Medium Earth Orbit (MEO) to provide position, navigation, and timing (PNT) service. The weak navigation signals limit its usage in deep attenuation environments, and make it easy to interference and counterfeit by jammers or spoofers. Moreover, being far away to the Earth results in relatively slow motion of the satellites in the sky and geometric change, making long time needed for achieved centimeter positioning accuracy. By using the satellites in Lower Earth Orbit (LEO) as the navigation satellites, these disadvantages can be addressed. In this contribution, the advantages of navigation from LEO constellation has been investigated and analyzed theoretically. The space segment of global Chinese BeiDou Navigation Satellite System consisting of three GEO, three IGSO, and 24 MEO satellites has been simulated with a LEO constellation with 120 satellites in 10 orbit planes with inclination of 55 degrees in a nearly circular orbit (eccentricity about 0.000001) at an approximate altitude of 975 km. With simulated data, the performance of LEO constellation to augment the global Chinese BeiDou Navigation Satellite System (BeiDou-3) has been assessed, as one of the example to show the promising of using LEO as navigation system. The results demonstrate that the satellite visibility and position dilution of precision have been significantly improved, particularly in mid-latitude region of Asia-Pacific region, once the LEO data were combined with BeiDou-3 for navigation. Most importantly, the convergence time for Precise Point Positioning (PPP) can be shorted from about 30 min to 1 min, which is essential and promising for real-time PPP application. Considering there are a plenty of commercial LEO communication constellation with hundreds or thousands of satellites, navigation from LEO will be an economic and promising way to change the heavily relay on GNSS systems.

scholarly journals Identifying GNSS market in Indonesia before and the future

2019 ◽  
Vol 94 ◽  
pp. 03010
Author(s):  
Heri Andreas ◽  
Sandy Noveriansyah
Keyword(s):  
Traffic Management ◽  
Small Deformation ◽  
Satellite System ◽  
Asia Pacific ◽  
South East Asia ◽  
Huge Amount ◽  
System A ◽  
Timing System ◽  
The Future ◽  
Global Navigation Satellite

Global Navigation Satellite System (GNSS) is one of the best finding of the twenty century world technologies. It is satellite base positioning and timing system. A millimeter accuracy of 4D positions can be provided by this GNSS system, allowed us to measure the geodynamic with millimeter per year signal only, measure small deformation and even the change of pole of earth rotation. Not to mention the GNSS for navigation and transportation system, it helps a lot in such traffic management, tracking, controlling, etc. GNSS market has contributed huge amount of dollars in world’s economy. Japan and America are two country of among others for biggest GNSS market so far. As for Indonesia, it is only part of 4% of Asia market in the early 2000. With such similar characteristic between Indonesia and Japan, especially relating to fast growing nation and the ring of fire, in this case market of GNSS in the future can be promising in Indonesia. This paper will highlight the GNSS market in Indonesia before and the future. We found that within ten to fifteen years the GNSS market in Indonesia will be the biggest around South East Asia and probably in Asia Pacific.

Developing a highly-available GNSS reference station network

2020 ◽  
Author(s):  
Ryan Ruddick ◽  
Amy Peterson ◽  
Richard Jacka ◽  
Bart Thomas
Keyword(s):  
Reference Frame ◽  
Satellite System ◽  
Asia Pacific ◽  
Community Safety ◽  
Reference Station ◽  
The Pacific ◽  
Australian Continent ◽  
Global Navigation Satellite ◽  
Geodetic Reference Frame ◽  
Reduced Data

<p>Having modern and well-maintained geodetic infrastructure is critical for the development of an accurate and reliable Global Geodetic Reference Frame (GGRF). Geoscience Australia (GA) contributes to the development of the GGRF through a network of Global Navigation Satellite System (GNSS) reference stations positioned in key locations across Australia, Antarctica and the Pacific. Data from these reference stations contribute to the realisation of the GGRF, the development and maintenance of the Asia-Pacific Reference frame and the monitoring of deformation across the Australian continent. We are also seeing a rapid increase in the use of this data for location-based positioning applications, such as civil engineering, transport, agriculture and community safety. These applications bring with them a new suite of challenges for geodetic infrastructure operators, such as reduced data latency, denser networks and accessing the latest signals in the most modern formats. Through the Positioning Australia program, GA is addressing these challenges by developing a modern highly-available GNSS reference station design that will be deployed at over 200 sites across the region. This paper discusses the concept of highly-available infrastructure and presents a GNSS reference station design that is openly available for use by the global geodetic community.</p>

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