Receiving and Assessing L1C Signal for In-Orbit GPS III and QZSS Transmissions Using a Software-Defined Receiver

To avoid signal interference in L1 frequency and provide various services, GPS has updated a modern signal, called L1C, which has been tested with three QZSS satellites launched in 2017. In December 2018, the first GPS III satellite was launched, which implies improved joint positioning using GPS and QZSS L1C signal. The L1C signal offers a series of advanced designs in signal modulation, message structure and coding. We present complete methodologies for joint L1C signal receiving and processing. For the transmitted signals, we present a methodology and results from collecting and assessing Binary Offset Carrier (BOC) modulation and time-multiplexed BOC (TMBOC) modulation used in the L1C signal. Using the same omnidirectional antenna and test equipment, we collected the L1C signal in Xi’an and Sanya, China, respectively. The experiments in Xi’an verify the joint positioning method to complement the GPS III and QZSS satellite constellations. Our methodology evaluates the ranging difference and positioning error of BOC and TMBOC modulation under the same environment and satellite constellation configuration in Sanya. It is also verified that the joint positioning error is less than the QZSS-only positioning due to the optimization of the satellite constellation.

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Fast Precise Positioning of Circular Mark in Automatic Optical Inspection

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.325-326.1614 ◽

2013 ◽

Vol 325-326 ◽

pp. 1614-1618

Author(s):

Guang Jie Xiong ◽

Yu Fei Liu ◽

Rui Zhen Liu

Keyword(s):

Printed Circuit Boards ◽

Positioning Error ◽

Circuit Boards ◽

Precise Positioning ◽

Automatic Optical Inspection ◽

Running Time ◽

Printed Circuit ◽

Optical Inspection ◽

Positioning Method ◽

The Difference

Captured circular marks are deformed sometimes when Automatic Optical Inspection (AOI) is used to detect various defects on Printed Circuit Boards (PCB), which may affect the precision of inspection. A new accurate positioning method of circular marks is proposed to solve the problem by obtaining the center of the most round ellipse based on the criterion that the ratio of the difference between the length and width of its circumscribed rectangle and the width of the rectangle is less than 0.1. The simulation tests show that, if the mark has much more deformations, the center positioning error of the proposed algorithm is about 0.013 pixels, and the running time is less than 40ms. Therefore, the proposed method provides good characteristics such as speediness, strong anti-interference ability and robustness.

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Research on spatial positioning of online inspection robots for vertical storage tanks

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-08-2019-0168 ◽

2019 ◽

Vol 47 (2) ◽

pp. 187-195

Author(s):

Zhiqiang Huang ◽

Lei He ◽

ZhaoXin Gao ◽

Yingqi Jia ◽

Yewei Kang ◽

...

Keyword(s):

Storage Tank ◽

Positioning Error ◽

Content Type ◽

Positioning Method ◽

Spatial Positioning ◽

Inspection Robots ◽

Positioning Algorithm ◽

Online Inspection ◽

Technology Level ◽

Acoustic Positioning

Purpose This paper aims to introduce a new acoustic positioning method to solve the problem of space positioning for online inspection robots within the storage tank. Design/methodology/approach The proposed positioning system comprises two acoustic signal emitters and two receivers. Emitters are brought by the robot into the storage tank. Receivers are mounted on the external edge of the storage tank floor. The spatial coordinate values and motion directions of the robot in the storage tank are calculated by using the proposed acoustic positioning algorithm. Findings The experiment results and positioning error analysis indicate that the method can obtain the data of robotic space coordinates and motion orientation, while the positioning error of the method can be less than 20 cm. The accuracy reaches the positioning technology level of other tank online inspection robots. Originality/value This method not only expands the positioning of the inspection robots from 2D plane to 3D space but also significantly reduces the number of positioning sensors carried by a robot and improves the safety of a robot in the tank.

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Exploration of Wireless Sensor Network Based on RSSI Positioning Algorithm

International Journal of Online Engineering (iJOE) ◽

10.3991/ijoe.v14i11.9519 ◽

2018 ◽

Vol 14 (11) ◽

pp. 133

Author(s):

Shuan Liu

Keyword(s):

Signal Strength ◽

Wireless Sensor ◽

Positioning Error ◽

Network Resources ◽

Simulation Experiments ◽

Wormhole Attack ◽

Positioning Method ◽

Physical Information ◽

Positioning Algorithm ◽

Node Energy

Based on the security of the receiving signal strength indicator positioning algorithm, the RSSI positioning algorithm in the environment of witch attack, wormhole attack and replication attack has largely failed.Although existing security positioning algorithms can effectively prevent attacks from occurring, the massive consumption of network resources can’t be ignored.Therefore, a tolerable security positioning method is proposed for each of the three attacks in order to improve the security of positioning.According to the node's physical information, the attack node is detected.Through simulation experiments, compared with the traditional indoor security positioning method, the proposed algorithm can significantly reduce the intervention of witch attack, wormhole attack and replication attack on positioning error.While achieving the goal of combating attacks, it reduces the computational complexity, decreases node energy consumption, and extends the network life cycle.

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Design Coverage Optimization Based on Position of Constellations and Cost of the Launch Vehicle

WSEAS TRANSACTIONS ON ENVIRONMENT AND DEVELOPMENT ◽

10.37394/232015.2021.17.107 ◽

2021 ◽

Vol 17 ◽

pp. 1160-1190

Author(s):

Saeid Kohani ◽

Peng Zong ◽

Fengfan Yang

Keyword(s):

Genetic Algorithms ◽

Optimal Design ◽

Launch Vehicle ◽

Multiple Objective ◽

Satellite Constellations ◽

Coverage Optimization ◽

Satellite Constellation ◽

Constellation Design ◽

Global Coverage ◽

Simulation Results

This research will analyze the tradeoffs between coverage optimization based on Position dilution of precision (PDOP) and cost of the launch vehicle. It adopts MATLAB and STK tools along with multiple objective genetic algorithms (MOGA) to explore the trade space for the constellation designs at different orbital altitudes. The objective of optimal design solutions is inferred to determine the economic and efficient LEO, MEO, HEO or hybrid constellations and simulation results are presented to optimize the design of satellite constellations. The benefits of this research are the optimization of satellite constellation design, which reduces costs and increases regional and global coverage with the least number of satellites. The result of this project is the optimization of the number of constellation satellites in several orbital planes in LEO orbit. Validations are based on reviewing the results of several simulations. The results of graphs and tables are presented in the last two sections and are taken from the results of several simulations.

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Indoor Three-Dimensional Positioning Method Based on CSS

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.556-562.3281 ◽

2014 ◽

Vol 556-562 ◽

pp. 3281-3286

Author(s):

Gao Ping Liu ◽

Jin Yan Zhang ◽

Ru Xiang Yang

Keyword(s):

Kalman Filtering ◽

Pressure Sensor ◽

Spread Spectrum ◽

Indoor Environment ◽

Three Dimensional ◽

Chirp Signal ◽

Positioning Error ◽

Filtering Method ◽

Positioning Method ◽

Chirp Spread Spectrum

This paper designs a three-dimensional positioning scheme suitable for indoor, adopts Chirp Spread Spectrum (CSS) and the particular Symmetric Double-Sided Two-Way Ranging (SDS-TWR). Combining BMP085 pressure sensor to measure altitude, it can implement three-dimensional positioning of a moving object in indoor. Due to the complex indoor environment would cause multipath effect when Chirp signal being transmitted, this scheme uses Kalman filtering method to filter out mutative coordinate value, thus the positioning error can be controlled within 1 m.

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Positioning Performance Limits of GNSS Meta-Signals and HO-BOC Signals

Sensors ◽

10.3390/s20123586 ◽

2020 ◽

Vol 20 (12) ◽

pp. 3586 ◽

Cited By ~ 1

Author(s):

Lorenzo Ortega ◽

Daniel Medina ◽

Jordi Vilà-Valls ◽

François Vincent ◽

Eric Chaumette

Keyword(s):

Intelligent Transportation Systems ◽

Single Point ◽

Transportation Systems ◽

Global Navigation Satellite Systems ◽

Performance Limits ◽

Binary Offset Carrier ◽

Ml Estimation ◽

Satellite Systems ◽

Satellite Constellation ◽

The Impact

Global Navigation Satellite Systems (GNSS) are the main source of position, navigation, and timing (PNT) information and will be a key player in the next-generation intelligent transportation systems and safety-critical applications, but several limitations need to be overcome to meet the stringent performance requirements. One of the open issues is how to provide precise PNT solutions in harsh propagation environments. Under nominal conditions, the former is typically achieved by exploiting carrier phase information through precise positioning techniques, but these methods are very sensitive to the quality of phase observables. Another option that is gaining interest in the scientific community is the use of large bandwidth signals, which allow obtaining a better baseband resolution, and therefore more precise code-based observables. Two options may be considered: (i) high-order binary offset carrier (HO-BOC) modulations or (ii) the concept of GNSS meta-signals. In this contribution, we assess the time-delay and phase maximum likelihood (ML) estimation performance limits of such signals, together with the performance translation into the position domain, considering single point positioning (SPP) and RTK solutions, being an important missing point in the literature. A comprehensive discussion is provided on the estimators’ behavior, the corresponding ML threshold regions, the impact of good and bad satellite constellation geometries, and final conclusions on the best candidates, which may lead to precise solutions under harsh conditions. It is found that if the receiver is constrained by the receiver bandwidth, the best choices are the L1-M or E6-Public Regulated Service (PRS) signals. If the receiver is able to operate at 60 MHz, it is recommended to exploit the full-bandwidth Galileo E5 signal. In terms of robustness and performance, if the receiver can operate at 135 MHz, the best choice is to use the GNSS meta-signals E5 + E6 or B2 + B3, which provide the best overall performances regardless of the positioning method used, the satellite constellation geometry, or the propagation conditions.

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An Adaptive Bluetooth/Wi-Fi Fingerprint Positioning Method based on Gaussian Process Regression and Relative Distance

Sensors ◽

10.3390/s19122784 ◽

2019 ◽

Vol 19 (12) ◽

pp. 2784 ◽

Cited By ~ 3

Author(s):

Hongji Cao ◽

Yunjia Wang ◽

Jingxue Bi ◽

Hongxia Qi

Keyword(s):

Gaussian Process ◽

Prediction Models ◽

Gaussian Process Regression ◽

Position Estimation ◽

Relative Distance ◽

Error Prediction ◽

Estimation Result ◽

Positioning Error ◽

Positioning Method ◽

Better Than

Trusted positioning data are very important for the fusion of Bluetooth fingerprint positioning (BFP) and Wi-Fi fingerprint positioning (WFP). This paper proposes an adaptive Bluetooth/Wi-Fi fingerprint positioning method based on Gaussian process regression (GPR) and relative distance (RD), which can choose trusted positioning results for fusion. In the offline stage, measurements of the Bluetooth and Wi-Fi received signal strength (RSS) were collected to construct Bluetooth and Wi-Fi fingerprint databases, respectively. Then, fingerprint positioning error prediction models were built with GPR and data from the fingerprint databases. In the online stage, online Bluetooth and Wi-Fi RSS readings were matched with the fingerprint databases to get a Bluetooth fingerprint positioning result (BFPR) and a Wi-Fi fingerprint positioning result (WFPR). Then, with the help of RD and fingerprint positioning error prediction models, whether the positioning results are trusted was determined. The trusted result is selected as the position estimation result when there is only one trusted positioning result among the BFPR and WFPR. The mean is chosen as the position estimation result when both the BFPR and WFPR results are trusted or untrusted. Experimental results showed that the proposed method was better than BFP and WFP, with a mean positioning error of 2.06 m and a root-mean-square error of 1.449 m.

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Positioning Method without Current Navigation Data

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.556-562.3234 ◽

2014 ◽

Vol 556-562 ◽

pp. 3234-3237

Author(s):

Ji Zhong Li ◽

Rui Wang

Keyword(s):

Objective Function ◽

Mobile Station ◽

Positioning Error ◽

Fuzzy Algorithm ◽

Reference Time ◽

Navigation Data ◽

Clock Error ◽

Positioning Errors ◽

Positioning Method ◽

Positioning Algorithm

Positioning errors were found through the analysis to AGPS positioning algorithm with mobile station (MS) clock error. These errors are engendered in the process of calculating the pseudo-range. Using fuzzy algorithm, the large positioning error of several hundred kilometers was eliminated. After this method, the objective function is quadratically related to the deviation of reference time. The objective function curve were fitted with three reference time values and determined the lowest point of curve to amend the reference time. This method removed residual positioning error.

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An Improved Indoor Positioning Method Based on Nearest Neighbor Interpolation

Network and Communication Technologies ◽

10.5539/nct.v6n1p1 ◽

2021 ◽

Vol 6 (1) ◽

pp. 1

Author(s):

Yonghao Zhao

Keyword(s):

Nearest Neighbor ◽

Indoor Positioning ◽

Location Information ◽

Positioning Error ◽

Positioning Accuracy ◽

Indoor Location ◽

Sampling Points ◽

Sampling Cost ◽

Positioning Method ◽

Positioning Algorithm

Nowadays, people’s demand for indoor location information is more and more, which continuously promotes the development of indoor positioning technology. In the field of indoor positioning, fingerprint based indoor positioning algorithm still accounts for a large proportion. However, the operation of this method in the offline stage is too cumbersome and time-consuming, which makes its disadvantages obvious, and requires a lot of manpower and time to sample and maintain. Therefore, in view of this phenomenon, an improved algorithm based on nearest neighbor interpolation is designed in this paper, which reduces the measurement of actual sampling points when establishing fingerprint map. At the same time, some simulation points are added to expand fingerprint map, so as to ensure that the positioning error will not become larger or even better. Experimental results show that this method can further improve the positioning accuracy while saving the sampling cost.

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High-Performance Fingerprint Localization in Massive MIMO System

10.3233/faia210456 ◽

2021 ◽

Author(s):

Yijie Ren ◽

Zhixing Xiao ◽

Yuan Tang ◽

Fei Tang ◽

Xiaojun Wang ◽

...

Keyword(s):

Massive Mimo ◽

High Performance ◽

Mimo Systems ◽

Mimo System ◽

Principal Component ◽

Development Projects ◽

Positioning Error ◽

Positioning Method ◽

Outdoor Localization ◽

Positioning Time

Location-based service (LBS) for both security and commercial use is becoming more and more important with the rise of 5G. Fingerprint localization (FL) is one of the most efficient positioning methods for both indoor and outdoor localization. However, the positioning time of previous research cannot achieve real-time requirement and the positioning error is meter level. In this paper, we concentrated on high-performance in massive multiple-in-multiple-out (MIMO) systems. Principal Component Analysis (PCA) is applied to reduce the dimension of fingerprint, so that the positioning time is about tens of milliseconds with lower storage. What’s more, a novel fingerprint called Angle Delay Fingerprint (ADF) is proposed. Simulation result of the positioning method based on ADF shows the positioning error is about 0.3 meter and the positioning time is about hundreds of milliseconds, which is much better than other previous known methods. (Foundation items: Social Development Projects of Jiangsu Science and Technology Department (No.BE2018704).)

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