scholarly journals Prospective directions for the development of microwave frequency standards for satellite navigation systems

2021 ◽  
Vol 2086 (1) ◽  
pp. 012073
Author(s):  
Ding Wang ◽  
V V Davydov ◽  
V Yu Rud
Keyword(s):  
Time Synchronization ◽  
Microwave Frequency ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Navigation Systems ◽  
Satellite Systems ◽  
Frequency Standards ◽  
Global Navigation ◽  
Satellite Navigation Systems ◽  
Global Navigation Satellite

Abstract The state of essential various quantum standards of GNSS frequencies for today are collected and presented, the results of analysis in the direction of modernization of time synchronization systems in global navigation satellite systems are presented. The most perspective directions of modernization of global navigation satellite systems are mentioned – the development of new atomic clocks on the mercury ions -199. The data on experimental satellite gives encouraging results.

scholarly journals GLOBAL NAVIGATION SATELLITE SYSTEMS AND THEIR ROLE IN PRECISION AGRICULTURE TECHNOLOGIES

2020 ◽  
pp. 71-87
Author(s):  
Oleksandr Kholodyuk
Keyword(s):  
Precision Agriculture ◽  
Satellite Navigation ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Navigation Systems ◽  
Satellite Systems ◽  
Global Positioning ◽  
Global Navigation ◽  
Satellite Navigation Systems ◽  
Global Navigation Satellite

Today, global navigation satellite systems are being implemented in many structural units of the Ukrainian economic complex, many spheres of human activity, and every year they continue to develop. One of the main feature of these satellite systems is the requirements for high accuracy and speed of received data. They provide the opportunity to reduce operating costs and increase the efficiency of use of equipment and other resources. Therefore, the use of navigation satellite systems for controlling machine units, establishing their location, monitoring soil condition and yield mapping is becoming increasingly relevant today. The subject of study in this article were global navigation satellite systems NAVSTARGPS (USA), GLONASS (RF), GALILEO (EU), BEIDOU (China) and regional navigation systems NavIC (India) and QUASI-ZENITH (Japan). The purpose of the work was to clarify and establish the main characteristics of global navigation satellite systems and their role in the implementation of precision agriculture technologies. The task of the work was: to analyze the functional characteristics of global positioning satellite systems and their main elements; to find out principles of operation of systems: navigation, coordinates, time; to establish the accuracy of navigation systems; to substantiate the role of global positioning satellite systems in the effective implementation of precision agriculture technologies in agriculture. The research methodology was based on the method of materialistic dialectics, methods of analysis and synthesis of both information from official sources and information from the works of other researchers. Two major operators of satellite navigation systems the NAVSTAR GPS and GLONASS, which are similar in many respects, have been identified in the scientific work. Among the distinctive features there are the nature of the location, the motion of satellites in orbits and their total number, methods of encoding the CDMA and FDMA signals, the use of different coordinate systems WGS-84 and PZ90.11. As for the other two satellite navigation systems GALILEO and BEIDOU, they are developing rapidly with great ambition and potential. It is established that at the present time the accuracy of determining the coordinates of the GLONASS system is inferior to the performance of the American satellite navigation system GPS. GLONASS provides more accurate positioning in the northern latitudes and GPS in the middle. It is noted that the positioning accuracy of machine units for the implementation of precision farming technologies can be improved (from 2 to 20 cm) due to differential signal correction with the help of free and commercial wideband satellite navigation subsystems. These services will allow to implement the tasks of precision driving, and therefore, to ensure the accurate implementation of sowing material, fertilizers and herbicides to spare them, accurate inter-row cultivation of industrial crops, accurate harvesting, etc., when performing agro-technological operations using ground vehicles and landless vehicles.

scholarly journals Assessment of the Implementation of GNSS into Gliding

2017 ◽  
Vol 5 (4) ◽  
pp. 6
Author(s):  
Tomáš Kubáč ◽  
Jakub Hospodka
Keyword(s):  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Navigation Systems ◽  
Satellite Systems ◽  
Global Navigation ◽  
Global Navigation Satellite ◽  
Global Navigation Systems ◽  
Usage Preference ◽  
Selection Of ◽  
Wide Usage

Global navigation satellite systems are increasingly part of our lives and many industries including aviation. Glider flying is no exception in this trend. Global navigation satellite systems were part of gliding since the early 1990s. First as official recording devices for simple evidence of sporting performances, then as navigation systems, anti-collision systems and emergency location transmitters. Development of recording application was initiated and supported by International Gliding Commission of World Air Sports Federation in way of certifications for flight recorders. The use of navigation and other modern instruments in gliders has brought many benefits but also risks. However, the advantages outweigh the disadvantages and these systems are now integral part of gliding. With this wide usage of global navigation satellite systems devices, there is great many possibilities how and in which way one can use these systems. Pilots must orient themselves in varied selection of products, which they can use to choose one solution, that fits him. Therefore, to find out how and if pilots use these devices, we created questionnaire survey among 143 Czech glider pilots. We found out, that 84% of them are using global navigation satellite systems devices for official record of flight and for navigation as well. More than half of pilots is using free, not built-in devices. Most common devices are mobile phones up to 5 inches of screen diagonal in combination with approved flight recorder without display. If pilots use mobile device for navigation, 52% of them is using one with Windows Mobile operating system, 33% use Android. Navigational software on these mobile devices is then almost tied between SeeYou Mobile, XCSoar and LK8000. Knowledge about usage preference of global navigation systems devices should help pilots with selection and overall orientation in subject.

An Innovative Approach for Atmospheric Error Mitigation Using New GNSS Signals

2011 ◽  
Vol 64 (S1) ◽  
pp. S211-S232 ◽  
Author(s):  
Lei Yang ◽  
Zeynep Elmas ◽  
Chris Hill ◽  
Marcio Aquino ◽  
Terry Moore
Keyword(s):  
High Accuracy ◽  
Global Navigation Satellite Systems ◽  
Tropospheric Delay ◽  
Atmospheric Effects ◽  
Navigation Satellite ◽  
Navigation Systems ◽  
Satellite Systems ◽  
Error Mitigation ◽  
Satellite Navigation Systems ◽  
Global Navigation Satellite

New signals from the modernised satellite navigation systems (GPS and GLONASS) and the ones that are being developed (COMPASS and GALILEO) will present opportunities for more accurate and reliable positioning solutions. Successful exploitation of these new signals will also enable the development of new markets and applications for difficult environments where the current Global Navigation Satellite Systems (GNSS) cannot provide satisfying solutions. This research is aiming to exploit the improvement in monitoring, modelling and mitigating the atmospheric effects using the increased number of signals from the future satellite systems. Preliminary investigations were conducted on the numerical weather parameter based horizontal tropospheric delay modelling, as well as the ionospheric higher order and scintillation effects. Results from this research are expected to provide a potential supplement to high accuracy positioning techniques.

Algorithms and Configuration for a Moving Object Attitude Control System Based on Microelectromechanical Sensors

2020 ◽  
pp. 44-58
Author(s):  
M.A. Ibrahim ◽  
V.V. Luk'yanov
Keyword(s):  
Attitude Control ◽  
Inertial Navigation ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Navigation Systems ◽  
Attitude Control System ◽  
Satellite Systems ◽  
Attitude Angle ◽  
Global Navigation ◽  
Global Navigation Satellite

Inertial systems for attitude control, stabilisation and navigation of moving objects boast a range of unique qualities, the most important of which are autonomy and interference immunity. At present, strap-down inertial navigation systems using inexpensive and compact microelectromechanical sensors are popular. The biggest disadvantage of the attitude control systems utilising microelectromechanical sensors is rapid error accumulation over time. The main error sources in strap-down inertial navigation systems are the errors of angular velocity sensors and accelerometers. Currently the accuracy required is ensured by the attitude control system processing the following two signals simultaneously: the magnetometer signal and the signal received from global navigation satellite systems such as GPS (NAVSTAR) and/or GLONASS. We developed an unconventional approach to integrating the two systems, that is, a strap-down inertial navigation system and a global navigation satellite system. It involves using the difference between the accelerations computed according to the global navigation satellite systems and those computed by the acelerometers and transformed to the geographic coordinate system for evaluating and compensating for the error of attitude angle assessment via the kinematic channel. Since this approach does not use integration of accelerometer readings, the attitude angle errors at the initial stage do not accumulate over time. Numerical simulation results of the algorithms developed show that the attainable attitude angle estimation accuracy significantly exceeds the accuracy of conventional methods

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