scholarly journals Trusted GNSS-Based Time Synchronization for Industry 4.0 Applications

2021 ◽  
Vol 11 (18) ◽  
pp. 8288
Author(s):  
Davide Margaria ◽  
Andrea Vesco
Keyword(s):  
Industry 4.0 ◽  
Time Synchronization ◽  
Trusted Computing ◽  
Satellite System ◽  
Correct Operation ◽  
Software Integrity ◽  
Radio Frequency Spectrum ◽  
Automation And Control ◽  
Global Navigation Satellite ◽  
Time Accuracy

The protection of satellite-derived timing information is becoming a fundamental requirement in Industry 4.0 applications, as well as in a growing number of critical infrastructures. All the industrial systems where several nodes or devices communicate and/or coordinate their functionalities by means of a communication network need accurate, reliable and trusted time synchronization. For instance, the correct operation of automation and control systems, measurement and automatic test systems, power generation, transmission, and distribution typically require a sub-microsecond time accuracy. This paper analyses the main attack vectors and stresses the need for software integrity control at network nodes of Industry 4.0 applications to complement existing security solutions that focus on Global Navigation Satellite System (GNSS) radio-frequency spectrum and Precision Time Protocol (PTP), also known as IEEE-1588. A real implementation of a Software Integrity Architecture in accordance with Trusted Computing principles concludes the work, together with the presentation of promising results obtained with a flexible and reconfigurable testbed for hands-on activities.

scholarly journals Fast Time Synchronization on Tens of Picoseconds Level Using Uncombined GNSS Carrier Phase of Zero/Short Baseline

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4882
Author(s):  
Yinghao Zhao ◽  
Letao Zhou ◽  
Wei Feng ◽  
Shaoguang Xu
Keyword(s):  
Carrier Phase ◽  
Time Synchronization ◽  
Satellite System ◽  
Fast Time ◽  
Short Baseline ◽  
Variation Characteristics ◽  
Single Difference ◽  
Short Baselines ◽  
Transfer Method ◽  
Global Navigation Satellite

Since the observation precision of the Global Navigation Satellite System (GNSS) carrier phase is on the order of millimeters, if the phase ambiguity is correctly solved, while calibrating the receiver inter-frequency bias, time synchronization on the order of tens of picoseconds is expected. In this contribution, a method that considers the prior constraints of the between-receiver inter-frequency bias (IFB) and its random variation characteristics is proposed for the estimation of the between-receiver clock difference, based on the uncombined GNSS carrier phase and pseudorange observations of the zero and short baselines. The proposed method can rapidly achieve the single-difference ambiguity resolution of the zero and short baselines, and then obtain the high-precision relative clock offset, by using only the carrier phase observations, along with the between-receiver IFBs being simultaneously determined. Our numerical tests, carried out using GNSS observations sampled every 30 s by a dedicatedly selected set of zero and short baselines, show that the method can fix the between-receiver single-difference ambiguity successfully within an average of fewer than 2 epochs (interval 30 s). Then, a clock difference between two receivers with millimeter precision is obtained, achieving time synchronization on tens of picoseconds level, and deriving a frequency stability of 5 × 10−14 for averaging times of 30,000 s. Furthermore, the proposed approach is compared with the precise point positioning (PPP) time transfer method. The results show that, for different types of receivers, the agreement between the two methods is between −6.7 ns and 0.2 ns.

scholarly journals Digital Recording Devices is Element of Safety of the Road Transport

2019 ◽  
Vol 26 (2) ◽  
pp. 115-120
Author(s):  
Marcin Rychter ◽  
Piotr Sułek
Keyword(s):  
Road Safety ◽  
Building Blocks ◽  
Road Transport ◽  
Satellite System ◽  
The European Union ◽  
Correct Operation ◽  
The Road ◽  
Technical Requirements ◽  
Driving Time ◽  
Global Navigation Satellite

Abstract The duty of applying recorders in the road transport was implemented in states of the European Union on regulations (EWG) no. 3820 / 85 on harmonizations of some social welfare legislation referring to the transport, which was changing with regulation (EWG) no. 3821/85 on recorders applied in the road transport. The duty of implementation of the digital tachograph is also considered in the context of improving road safety. Through the analysis of the records of the registering devices can be defined in each specific case of speeding by more than the allowable value in the area. Technical requirements for your device recorded in the resolution, which defines the main parameters, are measured, among things other, the traversed path length of the car, speed, time driving, other periods of work, politeness of the driver and the correct operation of the check authorized for those authorities. At present led Regulation (EU) No 165/2014 of European Parliament establishing requirements concerning structure, checking, installation, use and repairs of tachographs and their building blocks is implementing the second generation of the digital tachographs connected with the device GNSS (Global Navigation Satellite System). Organizing the early detection from a distance is showing data officers from the digital tachograph and information concerning mass and mass falling on the wasp of the entire team of vehicles. Experience in work, economic pressures and competition in transport has led the drivers through a transport company in the event noncompliance, and in particular, in relation to the driving time and breaks. This article contains responsibilities after part rest on the drivers of vehicles takes the issues of system security and optimum performance of recording devices.

The Research on Positioning Based on Digital Television Signal and GNSS

2012 ◽  
Vol 429 ◽  
pp. 132-136
Author(s):  
Ke Xin Song ◽  
Yu Hua ◽  
Yu Xiang ◽  
Chang Jiang Huang
Keyword(s):  
Time Synchronization ◽  
Satellite System ◽  
Measured Data ◽  
National Standard ◽  
Digital Television ◽  
Republic Of China ◽  
Gnss Positioning ◽  
Television Signal ◽  
Global Navigation Satellite ◽  
System Time

Global Navigation Satellite System (GNSS) is precise and efficient in positioning and navigation in so many fields of military and civilian affairs. However, the GNSS signal is commonly kept out and interfered inside the buildings and the area dense with people, so the GNSS positioning possibility is low and the capability is bad. Digital television terrestrial broadcasting signal is powerful in sending power, low in frequency and wide in base bandwidth, so it is good, real time, and absolute entire to cover the metropolis including many streets and buildings where GNSS signal is not reachable. Considering these characteristics of digital television terrestrial broadcasting signal, the results is good that positioning the receiver location combined with GNSS and digital television terrestrial broadcasting signal. In this paper the signal structure is analyzed which is regulated by the national standard of People’s Republic of China GB20600-2006. The method of measuring the time delay of signal broadcasting is presented. The system time synchronization is finished when the number of satellite is satisfied to position the receiver in its scope. Then, the positioning combined with GNSS and digital television signal is achieved. At last practice measured data in Xi’an is analyzed and the conclusion is given.

scholarly journals Augmentation of GNSS by Low-Cost MEMS IMU, OBD-II, and Digital Altimeter for Improved Positioning in Urban Area

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3830 ◽  
Author(s):  
JoonHoo Lim ◽  
Won Yoo ◽  
La Kim ◽  
You Lee ◽  
Hyung Lee
Keyword(s):  
Urban Area ◽  
Time Synchronization ◽  
Low Cost ◽  
Satellite System ◽  
Adaptive Synchronization ◽  
Measurement Unit ◽  
Micro Electro Mechanical Systems ◽  
Improved Performance ◽  
Global Navigation Satellite ◽  
Mems Imu

This paper proposes an efficient multi-sensor system to complement GNSS (Global Navigation Satellite System) for improved positioning in urban area. The proposed system augments GNSS by low-cost MEMS IMU (Micro Electro Mechanical Systems Inertial Measurement Unit), OBD (On-Board Diagnostics)-II, and digital altimeter modules. For improved availability of time synchronization in urban area, an adaptive synchronization method is proposed to combine the external PPS (Pulse Per Second) signal and the internal onboard clock. For improved positioning accuracy and availability, a 17-state Kalman filter is formulated for efficient multi-sensor fusion, including OBD-II and digital altimeter modules. A strategy to apply different types of measurement updates is also proposed for improved performance in urban area. Four experiment results with field-collected measurements evaluates the performance of the proposed GNSS/IMU/OBD-II/altimeter system in various aspects, including accuracy, precision, continuity, and availability.

scholarly journals Georeferencing of Multi-Channel GPR—Accuracy and Efficiency of Mapping of Underground Utility Networks

2020 ◽  
Vol 12 (18) ◽  
pp. 2945
Author(s):  
Marta Gabryś ◽  
Łukasz Ortyl
Keyword(s):  
Time Synchronization ◽  
Amplitude Distribution ◽  
Satellite System ◽  
Destructive Testing ◽  
High Rise ◽  
Wide Range ◽  
Urban Character ◽  
Global Navigation Satellite ◽  
Ground Penetrating ◽  
Urban Conditions

Due to the capabilities of non-destructive testing of inaccessible objects, GPR (Ground Penetrating Radar) is used in geology, archeology, forensics and increasingly also in engineering tasks. The wide range of applications of the GPR method has been provided by the use of advanced technological solutions by equipment manufacturers, including multi-channel units. The acquisition of data along several profiles simultaneously allows time to be saved and quasi-continuous information to be collected about the subsurface situation. One of the most important aspects of data acquisition systems, including GPR, is the appropriate methodology and accuracy of the geoposition. This publication aims to discuss the results of GPR measurements carried out using the multi-channel Leica Stream C GPR (IDS GeoRadar Srl, Pisa, Italy). The significant results of the test measurement were presented the idea of which was to determine the achievable accuracy depending on the georeferencing method using a GNSS (Global Navigation Satellite System) receiver, also supported by time synchronization PPS (Pulse Per Second) and a total station. Methodology optimization was also an important aspect of the discussed issue, i.e., the effect of dynamic changes in motion trajectory on the positioning accuracy of echograms and their vectorization products was also examined. The standard algorithms developed for the dedicated software were used for post-processing of the coordinates and filtration of echograms, while the vectorization was done manually. The obtained results provided the basis for the confrontation of the material collected in urban conditions with the available cartographic data in terms of the possibility of verifying the actual location of underground utilities. The urban character of the area limited the possibility of the movement of Leica Stream C due to the large size of the instrument, however, it created the opportunity for additional analyses, including the accuracy of different location variants around high-rise buildings or the agreement of the amplitude distribution at the intersection of perpendicular profiles.

scholarly journals Tracing Students Attendance During Covid-19 Pandemic by Applying Location Detection Technology

2021 ◽  
Vol 58 (1) ◽  
pp. 5441-5446
Author(s):  
Julaily Aida Jusoh Et al.
Keyword(s):  
Online Learning ◽  
Distance Learning ◽  
Time Synchronization ◽  
Satellite System ◽  
Learning Session ◽  
Face To Face ◽  
Detection Technology ◽  
Location Detection ◽  
Face To Face Learning ◽  
Global Navigation Satellite

The Covid-19 pandemic outbreak has initiated the learning process to switch from face-to-face learning methods to open distance learning. The open distance learning is a concept of students assessing the lectures from different venues.  Among the activities that are affected by that change, are the process of recording student’s attendance and engagement during the online lectures, as opposed to the normal method of being in the same classroom during the lecture. The Global Positioning System (GPS) is a global navigation satellite system that provides location and time synchronization. This approach can assist lecturers in tracking the position of their students throughout the learning session. The operation of the GPS is based on the trilateration method where the position is determined from the distance measurement to satellites. Therefore, iHadir has been proposed to overcome the issue of tracking the students’ attendance. The iHadir is a mobile-based application system that can detect student’s location during the learning session. This application can be used as a new alternative in monitoring the student’s attendance during online learning. The iHadir will help in increasing the effectiveness of attendance’s record during online learning.  

The characteristics of transforming coordinates from the geocentric system WGS-84 for the Mercator projection under low latitudes conditions

2018 ◽  
Vol 940 (10) ◽  
pp. 2-6
Author(s):  
J.A. Younes ◽  
M.G. Mustafin
Keyword(s):  
Coordinate System ◽  
Satellite System ◽  
Programming Algorithm ◽  
Low Latitude ◽  
Model Calculations ◽  
Mercator Projection ◽  
Low Latitudes ◽  
Rectangular Coordinates ◽  
Global Navigation Satellite ◽  
Coordination Methods

The issue of calculating the plane rectangular coordinates using the data obtained by the satellite observations during the creation of the geodetic networks is discussed in the article. The peculiarity of these works is in conversion of the coordinates into the Mercator projection, while the plane coordinate system on the base of Gauss-Kruger projection is used in Russia. When using the technology of global navigation satellite system, this task is relevant for any point (area) of the Earth due to a fundamentally different approach in determining the coordinates. The fact is that satellite determinations are much more precise than the ground coordination methods (triangulation and others). In addition, the conversion to the zonal coordinate system is associated with errors; the value at present can prove to be completely critical. The expediency of using the Mercator projection in the topographic and geodetic works production at low latitudes is shown numerically on the basis of model calculations. To convert the coordinates from the geocentric system with the Mercator projection, a programming algorithm which is widely used in Russia was chosen. For its application under low-latitude conditions, the modification of known formulas to be used in Saudi Arabia is implemented.

scholarly journals Detecting Apples in the Wild: Potential for Harvest Quantity Estimation

2021 ◽  
Vol 13 (14) ◽  
pp. 8054
Author(s):  
Artur Janowski ◽  
Rafał Kaźmierczak ◽  
Cezary Kowalczyk ◽  
Jakub Szulwic
Keyword(s):  
Image Analysis ◽  
Pilot Study ◽  
Production Management ◽  
Satellite System ◽  
Morphological Operations ◽  
Computational Performance ◽  
Analysis Methods ◽  
Manual Counting ◽  
In The Wild ◽  
Global Navigation Satellite

Knowing the exact number of fruits and trees helps farmers to make better decisions in their orchard production management. The current practice of crop estimation practice often involves manual counting of fruits (before harvesting), which is an extremely time-consuming and costly process. Additionally, this is not practicable for large orchards. Thanks to the changes that have taken place in recent years in the field of image analysis methods and computational performance, it is possible to create solutions for automatic fruit counting based on registered digital images. The pilot study aims to confirm the state of knowledge in the use of three methods (You Only Look Once—YOLO, Viola–Jones—a method based on the synergy of morphological operations of digital imagesand Hough transformation) of image recognition for apple detecting and counting. The study compared the results of three image analysis methods that can be used for counting apple fruits. They were validated, and their results allowed the recommendation of a method based on the YOLO algorithm for the proposed solution. It was based on the use of mass accessible devices (smartphones equipped with a camera with the required accuracy of image acquisition and accurate Global Navigation Satellite System (GNSS) positioning) for orchard owners to count growing apples. In our pilot study, three methods of counting apples were tested to create an automatic system for estimating apple yields in orchards. The test orchard is located at the University of Warmia and Mazury in Olsztyn. The tests were carried out on four trees located in different parts of the orchard. For the tests used, the dataset contained 1102 apple images and 3800 background images without fruits.

GPS-BDS-Galileo double-differenced stochastic model refinement based on least-squares variance component estimation

2021 ◽  
pp. 1-16
Author(s):  
Hong Hu ◽  
Xuefeng Xie ◽  
Jingxiang Gao ◽  
Shuanggen Jin ◽  
Peng Jiang
Keyword(s):  
Stochastic Model ◽  
Least Squares ◽  
Stochastic Models ◽  
Variance Component ◽  
Satellite System ◽  
Variance Component Estimation ◽  
Short Baseline ◽  
Component Estimation ◽  
Zero Baseline ◽  
Global Navigation Satellite

Abstract Stochastic models are essential for precise navigation and positioning of the global navigation satellite system (GNSS). A stochastic model can influence the resolution of ambiguity, which is a key step in GNSS positioning. Most of the existing multi-GNSS stochastic models are based on the GPS empirical model, while differences in the precision of observations among different systems are not considered. In this paper, three refined stochastic models, namely the variance components between systems (RSM1), the variances of different types of observations (RSM2) and the variances of observations for each satellite (RSM3) are proposed based on the least-squares variance component estimation (LS-VCE). Zero-baseline and short-baseline GNSS experimental data were used to verify the proposed three refined stochastic models. The results show that, compared with the traditional elevation-dependent model (EDM), though the proposed models do not significantly improve the ambiguity resolution success rate, the positioning precision of the three proposed models has been improved. RSM3, which is more realistic for the data itself, performs the best, and the precision at elevation mask angles 20°, 30°, 40°, 50° can be improved by 4⋅6%, 7⋅6%, 13⋅2%, 73⋅0% for L1-B1-E1 and 1⋅1%, 4⋅8%, 16⋅3%, 64⋅5% for L2-B2-E5a, respectively.

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