scholarly journals Unambiguous BPSK-like CSC Method for Galileo Acquisition

2021 ◽  
Vol 15 ◽  
pp. 171-176
Author(s):  
Wei-Lung Mao ◽  
Chorng-Sii Hwang ◽  
Chung-Wen Hung ◽  
Jyh Sheen ◽  
Po-Hung Chen
Keyword(s):  
Detection Probability ◽  
Search Algorithm ◽  
Satellite System ◽  
Navigation Satellite ◽  
Code Length ◽  
Hardware Complexity ◽  
Code Structure ◽  
Hardware Resource ◽  
Simulation Results ◽  
Global Navigation Satellite

Galileo will be Europe’s own Global Navigation Satellite System (GNSS), which is aiming to provide highly accurate and guaranteed positioning services. Galileo E1 system has a code period of 4ms which is quadruple that of GPS C/A code. In other words, due to the large number of hypotheses in code phase at acquisition stage, a longer searching time or more hardware resource is required. It is difficult to acquire Galileo signal because of longer code length and the multiple peaks of autocorrelation function of BOC modulation. In this paper, the cyclically shift-and-combine (CSC) and BPSK-like architectures are employed to resolve the unambiguous acquisition for BOC modulation and acquires these satellite signals with hardware complexity reduction. The concept of CSC code is to modify the code structure and shorten the code period such that the acquisition burden can be decreased. Simulation results show that our proposed search algorithm can provide better performances in terms of low hardware complexity for acquiring these satellite signals and detection probability at the low value of CNR.

Analysis of Deep Space Navigation Feasibility Based on Inter-Satellite Link Antenna of Satellite Navigation System

2013 ◽  
Vol 411-414 ◽  
pp. 917-921
Author(s):  
Dong Hui Wang ◽  
Wen Xiang Liu
Keyword(s):  
Satellite System ◽  
Geosynchronous Orbit ◽  
Navigation Satellite ◽  
Deep Space ◽  
Positioning Accuracy ◽  
Satellite Navigation System ◽  
Space Navigation ◽  
Simulation Results ◽  
Global Navigation Satellite ◽  
Navigation Method

There is no effectual navigation method to deep space aerocraft until now. Global Navigation Satellite System (GNSS) is a candidate. Its feasibility was analyzed according to the deep space geometry coverage characteristics. The antenna elevation was optimally designed to maximum the signal coverage performance in deep space. Simulation Results show that the best antenna elevation is 50-90 degrees. At the height of geosynchronous orbit, the average PDOP is 8.63, and at the height of lunar orbit, the positioning accuracy can only be achieved by km level.

scholarly journals A Subset-Reduced Method for FDE ARAIM of Tightly-Coupled GNSS/INS

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4847
Author(s):  
Weichuan Pan ◽  
Xingqun Zhan ◽  
Xin Zhang ◽  
Shizhuang Wang
Keyword(s):  
Global Navigation Satellite System ◽  
Inertial Navigation System ◽  
Satellite System ◽  
Civil Aviation ◽  
Navigation Satellite ◽  
Tightly Coupled ◽  
Simulation Results ◽  
Receiver Autonomous Integrity Monitoring ◽  
Global Navigation Satellite ◽  
Advanced Receiver

The advanced receiver autonomous integrity monitoring (advanced RAIM, ARAIM) is the next generation of RAIM which is widely used in civil aviation. However, the current ARAIM needs to evaluate hundreds of subsets, which results in huge computational loads. In this paper, a method using the subset excluding entire constellation to evaluate the single satellite fault subsets and the simultaneous multiple satellites fault subsets is presented. The proposed ARAIM algorithm is based on the tight integration of the global navigation satellite system (GNSS) and inertial navigation system (INS). The number of subsets that the proposed GNSS/INS ARAIM needs to consider is about 2% of that of the current ARAIM, which reduces the computational load dramatically. The detailed fault detection (FD) process and fault exclusion (FE) process of the proposed GNSS/INS ARAIM are provided. Meanwhile, the method to obtain the FD-only integrity bound and the after-exclusion integrity bound is also presented in this paper. The simulation results show that the proposed GNSS/INS ARAIM is able to find the failing satellite accurately and its integrity performance is able to meet the integrity requirements of CAT-I precision approach.

Assessment Models and Rules of GNSS Interoperability

2013 ◽  
Vol 846-847 ◽  
pp. 808-811
Author(s):  
Wei Wang ◽  
Cheng Cai Lv ◽  
Xin Li
Keyword(s):  
Global Navigation Satellite System ◽  
Satellite System ◽  
System Level ◽  
Navigation Satellite ◽  
Weighted Sum ◽  
Dilution Of Precision ◽  
Satellite Systems ◽  
System Integrity ◽  
Simulation Results ◽  
Global Navigation Satellite

Global Navigation Satellite System (GNSS) interoperability could make use of the information from different navigation satellite systems. To estimate GNSS interoperability at the system level, an innovative assessment algorithm was presented in this paper. First of all, three assessment parameters, namely, Dilution Of Precision (DOP), Navigation Satellite System Precision (NSSP) and Navigation Satellite System Integrity (NSSI) were introduced. Secondly, availability and continuity of the assessment parameters were adopted to quantify the GNSS performance. A further step was then taken to focus on the assessment rule for GNSS performance by employing the weighted sum of availability and continuity. Simulation results demonstrate that GNSS performance could be improved significantly by interoperability.

scholarly journals Performance of TPC based ranging signal for more than 2 services multiplexing

2019 ◽  
Vol 94 ◽  
pp. 03007
Author(s):  
Seung Tae Kim ◽  
Kap-Jin Kim ◽  
Ki-Won Song ◽  
Jae Min Ahn
Keyword(s):  
Global Navigation Satellite System ◽  
Power Efficiency ◽  
Satellite System ◽  
Navigation Satellite ◽  
Constant Envelope ◽  
Efficiency Performance ◽  
Simulation Results ◽  
Envelope Signal ◽  
Global Navigation Satellite ◽  
Simultaneous Transmission

This paper presents signal structure and power efficiency performance for simultaneous transmission of Global Navigation Satellite System (GNSS) service signals based on Tiered Polyphase Code (TPC). For the simultaneous transmission of three or more service signals, the intermodulation terms addition and modification of the power allocations for the signal multiplexing are applied first to the spreading signal with the binary pseudorandom noise (PRN) code and a constant envelope signal is generated. Then, Zadoff-Chu sequence is applied as a secondary code to generate a multiplexed satellite navigation signal having a constant envelope characteristic. Simulation results show that power efficiency performance of more than 80% can be achieved in three service signal multiplexing.

scholarly journals Estimation of fractional cycle bias for GPS/BDS-2/Galileo based on international GNSS monitoring and assessment system observations using the uncombined PPP model

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jin Wang ◽  
Qin Zhang ◽  
Guanwen Huang
Keyword(s):  
Estimation Method ◽  
Satellite Orbit ◽  
Satellite System ◽  
Assessment System ◽  
Navigation Satellite ◽  
Dual Frequency ◽  
Fractional Cycle Bias ◽  
The Stability ◽  
High Consistency ◽  
Global Navigation Satellite

AbstractThe Fractional Cycle Bias (FCB) product is crucial for the Ambiguity Resolution (AR) in Precise Point Positioning (PPP). Different from the traditional method using the ionospheric-free ambiguity which is formed by the Wide Lane (WL) and Narrow Lane (NL) combinations, the uncombined PPP model is flexible and effective to generate the FCB products. This study presents the FCB estimation method based on the multi-Global Navigation Satellite System (GNSS) precise satellite orbit and clock corrections from the international GNSS Monitoring and Assessment System (iGMAS) observations using the uncombined PPP model. The dual-frequency raw ambiguities are combined by the integer coefficients (4,− 3) and (1,− 1) to directly estimate the FCBs. The details of FCB estimation are described with the Global Positioning System (GPS), BeiDou-2 Navigation Satellite System (BDS-2) and Galileo Navigation Satellite System (Galileo). For the estimated FCBs, the Root Mean Squares (RMSs) of the posterior residuals are smaller than 0.1 cycles, which indicates a high consistency for the float ambiguities. The stability of the WL FCBs series is better than 0.02 cycles for the three GNSS systems, while the STandard Deviation (STD) of the NL FCBs for BDS-2 is larger than 0.139 cycles. The combined FCBs have better stability than the raw series. With the multi-GNSS FCB products, the PPP AR for GPS/BDS-2/Galileo is demonstrated using the raw observations. For hourly static positioning results, the performance of the PPP AR with the three-system observations is improved by 42.6%, but only 13.1% for kinematic positioning results. The results indicate that precise and reliable positioning can be achieved with the PPP AR of GPS/BDS-2/Galileo, supported by multi-GNSS satellite orbit, clock, and FCB products based on iGMAS.

scholarly journals Performance evaluation of multi-GNSSs navigation in super synchronous transfer orbit and geostationary earth orbit

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Tao Shi ◽  
Xuebin Zhuang ◽  
Liwei Xie
Keyword(s):  
Global Navigation Satellite System ◽  
Autonomous Navigation ◽  
Satellite System ◽  
Earth Orbit ◽  
Navigation Satellite ◽  
Geostationary Earth Orbit ◽  
Beidou Navigation Satellite System ◽  
Transfer Orbit ◽  
High Orbit ◽  
Global Navigation Satellite

AbstractThe autonomous navigation of the spacecrafts in High Elliptic Orbit (HEO), Geostationary Earth Orbit (GEO) and Geostationary Transfer Orbit (GTO) based on Global Navigation Satellite System (GNSS) are considered feasible in many studies. With the completion of BeiDou Navigation Satellite System with Global Coverage (BDS-3) in 2020, there are at least 130 satellites providing Position, Navigation, and Timing (PNT) services. In this paper, considering the latest CZ-5(Y3) launch scenario of Shijian-20 GEO spacecraft via Super-Synchronous Transfer Orbit (SSTO) in December 2019, the navigation performance based on the latest BeiDou Navigation Satellite System (BDS), Global Positioning System (GPS), Galileo Navigation Satellite System (Galileo) and GLObal NAvigation Satellite System (GLONASS) satellites in 2020 is evaluated, including the number of visible satellites, carrier to noise ratio, Doppler, and Position Dilution of Precision (PDOP). The simulation results show that the GEO/Inclined Geo-Synchronous Orbit (IGSO) navigation satellites of BDS-3 can effectively increase the number of visible satellites and improve the PDOP in the whole launch process of a typical GEO spacecraft, including SSTO and GEO, especially for the GEO spacecraft on the opposite side of Asia-Pacific region. The navigation performance of high orbit spacecrafts based on multi-GNSSs can be significantly improved by the employment of BDS-3. This provides a feasible solution for autonomous navigation of various high orbit spacecrafts, such as SSTO, MEO, GEO, and even Lunar Transfer Orbit (LTO) for the lunar exploration mission.

scholarly journals OutFin, a multi-device and multi-modal dataset for outdoor localization based on the fingerprinting approach

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Fahad Alhomayani ◽  
Mohammad H. Mahoor
Keyword(s):  
Global Navigation Satellite System ◽  
Urban Areas ◽  
Satellite System ◽  
Reference Points ◽  
Navigation Satellite ◽  
Data Types ◽  
Entry Barrier ◽  
Promising Alternative ◽  
Global Navigation ◽  
Global Navigation Satellite

AbstractIn recent years, fingerprint-based positioning has gained researchers’ attention since it is a promising alternative to the Global Navigation Satellite System and cellular network-based localization in urban areas. Despite this, the lack of publicly available datasets that researchers can use to develop, evaluate, and compare fingerprint-based positioning solutions constitutes a high entry barrier for studies. As an effort to overcome this barrier and foster new research efforts, this paper presents OutFin, a novel dataset of outdoor location fingerprints that were collected using two different smartphones. OutFin is comprised of diverse data types such as WiFi, Bluetooth, and cellular signal strengths, in addition to measurements from various sensors including the magnetometer, accelerometer, gyroscope, barometer, and ambient light sensor. The collection area spanned four dispersed sites with a total of 122 reference points. Each site is different in terms of its visibility to the Global Navigation Satellite System and reference points’ number, arrangement, and spacing. Before OutFin was made available to the public, several experiments were conducted to validate its technical quality.

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