scholarly journals The key role of GNSS for monitoring geodetic parameters of the Earth

2021 ◽  
pp. 10-15
Author(s):  
С.П. Кузин
Keyword(s):  
Weather Conditions ◽  
Signal Propagation ◽  
Global Navigation Satellite Systems ◽  
Navigation Systems ◽  
Microwave Range ◽  
Satellite Systems ◽  
Ground Segment ◽  
The Earth ◽  
Gnss Receivers ◽  
Global Navigation Satellite

Глобальные навигационные спутниковые системы (ГНСС) являются основным инструментом для контроля геодезических параметров Земли, построения и постоянного контроля земной системы отсчета и связи измерений различных спутниковых геодезических технологий. ГНСС состоят из наземного сегмента (приемники ГНСС) и орбитальной группировки (навигационные спутники системы). Микроволновый диапазон сигналов ГНСС позволяет использовать данные системы при любых погодных условиях, а двухчастотные несущие позволяют, в значительной степени, исключить ионосферную задержку распространения сигналов. Помимо выполнения основных геодезических определений навигационные системы также могут быть использованы для решения социальных и других позиционных измерений, требующих высокой точности. В данной статье автором рассмотрены основные задачи, решаемые ГНСС, определены требования к точности продуктов навигационных систем и приведены направления развития наземной и орбитальных частей ГНСС, учитывая потребности мирового геодезического сообщества. Global navigation satellite systems (GNSS) are a fundamental tool for monitoring geodesic parameters of the Earth, building and constantly monitoring the Earth’s reference system and connecting measurements of various satellite geodetic technologies. GNSS consist of a ground segment (GNSS receivers) and an orbital grouping (navigation satellites of the system). The microwave range of GNSS signals allows using these systems in all weather conditions, and the two-frequency carriers allow, to a large extent, eliminating the ionospheric delay of signal propagation. In addition to performing basic geodetic definitions, GNSS can also be used to solve social and other positional measurements that require high accuracy. In this article the author discusses the main tasks solved by GNSS, defines the requirements for the accuracy of navigation systems products, and provides directions for the development of the ground and orbital parts of GNSS taking into account the needs of the international geodetic community.

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.

scholarly journals Seamless Vehicle Positioning by Lidar-GNSS Integration: Standalone and Multi-Epoch Scenarios

2021 ◽  
Vol 13 (22) ◽  
pp. 4525
Author(s):  
Junjie Zhang ◽  
Kourosh Khoshelham ◽  
Amir Khodabandeh
Keyword(s):  
Autonomous Driving ◽  
Measurement Model ◽  
Urban Environments ◽  
Global Navigation Satellite Systems ◽  
High Definition ◽  
Satellite Systems ◽  
The Road ◽  
Gnss Receivers ◽  
Vehicle Positioning ◽  
Global Navigation Satellite

Accurate and seamless vehicle positioning is fundamental for autonomous driving tasks in urban environments, requiring the provision of high-end measuring devices. Light Detection and Ranging (lidar) sensors, together with Global Navigation Satellite Systems (GNSS) receivers, are therefore commonly found onboard modern vehicles. In this paper, we propose an integration of lidar and GNSS code measurements at the observation level via a mixed measurement model. An Extended Kalman-Filter (EKF) is implemented to capture the dynamic of the vehicle movement, and thus, to incorporate the vehicle velocity parameters into the measurement model. The lidar positioning component is realized using point cloud registration through a deep neural network, which is aided by a high definition (HD) map comprising accurately georeferenced scans of the road environments. Experiments conducted in a densely built-up environment show that, by exploiting the abundant measurements of GNSS and high accuracy of lidar, the proposed vehicle positioning approach can maintain centimeter-to meter-level accuracy for the entirety of the driving duration in urban canyons.

scholarly journals Kalman Filter-Based RAIM for Reliable Aircraft Positioning with GPS and NavIC Constellations

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6606
Author(s):  
Susmita Bhattacharyya ◽  
Dinesh Mute
Keyword(s):  
Kalman Filter ◽  
Weighted Least Squares ◽  
Unmanned Aircraft ◽  
Global Navigation Satellite Systems ◽  
Navigation Systems ◽  
Satellite Systems ◽  
Vector Tracking ◽  
Receiver Autonomous Integrity Monitoring ◽  
Global Navigation Satellite ◽  
Computational Resources

This paper presents a novel Kalman filter (KF)-based receiver autonomous integrity monitoring (RAIM) algorithm for reliable aircraft positioning with global navigation satellite systems (GNSS). The presented method overcomes major limitations of the authors’ previous work, and uses two GNSS, namely, Navigation with Indian Constellation (NavIC) of India and the Global Positioning System (GPS). The algorithm is developed in the range domain and compared with two existing approaches—one each for the weighted least squares navigation filter and KF. Extensive simulations were carried out for an unmanned aircraft flight path over the Indian sub-continent for validation of the new approach. Although both existing methods outperform the new one, the work is significant for the following reasons. KF is an integral part of advanced navigation systems that can address frequent loss of GNSS signals (e.g., vector tracking and multi-sensor integration). Developing KF RAIM algorithms is essential to ensuring their reliability. KF solution separation (or position domain) RAIM offers good performance at the cost of high computational load. Presented range domain KF RAIM, on the other hand, offers satisfactory performance to a certain extent, eliminating a major issue of growing position error bounds over time. It requires moderate computational resources, and hence, shows promise for real-time implementations in avionics. Simulation results also indicate that addition of NavIC alongside GPS can substantially improve RAIM performance, particularly in poor geometries.

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.

scholarly journals Low cost GNSS receivers in time synchronization systems

2018 ◽  
Vol 67 (1) ◽  
pp. 65-72
Author(s):  
Grzegorz Czopik ◽  
Tomasz Kraszewski
Keyword(s):  
Time Synchronization ◽  
Low Cost ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Time Frequency ◽  
Delay Times ◽  
Gnss Receivers ◽  
Frequency Counter ◽  
The One ◽  
Global Navigation Satellite

The GNSS (GNSS — Global Navigation Satellite Systems) receivers can be utilized to obtain accurate time markers. The preliminary results of the cheap GNSS receivers’ tests are presented in the paper. The one receiver’s price (including antenna) does not exceed 30 $. The studies on the use of receivers in the time synchronization systems were executed. Three identical models of receiver modules were used. The 1PPS (1PPS — 1 Pulse Per Second) signals available on the receiver’s output were used. The 1PPS’s main time characteristics were described. Delay times between different receivers 1PPS signals were measured. Measurements were taken using 1 GHz oscilloscope and precise time/frequency counter T3200U. Keywords: time synchronization, 1PPS, GNSS, GPS time

scholarly journals Linear and Nonlinear Deformation Effects in the Permanent GNSS Network of Cyprus

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1768
Author(s):  
Chris Danezis ◽  
Miltiadis Chatzinikos ◽  
Christopher Kotsakis
Keyword(s):  
Crustal Deformation ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Time Period ◽  
Position Time Series ◽  
Gnss Receivers ◽  
Linear And Nonlinear ◽  
Gnss Network ◽  
Global Navigation Satellite ◽  
Gnss Data

Permanent Global Navigation Satellite Systems (GNSS) reference stations are well established as a powerful tool for the estimation of deformation induced by man-made or physical processes. GNSS sensors are successfully used to determine positions and velocities over a specified time period, with unprecedented accuracy, promoting research in many safety-critical areas, such as geophysics and geo-tectonics, tackling problems that torment traditional equipment and providing deformation products with absolute accuracy. Cyprus, being located at the Mediterranean fault, exhibits a very interesting geodynamic regime, which has yet to be investigated thoroughly. Accordingly, this research revolves around the estimation of crustal deformation in Cyprus using GNSS receivers. CYPOS (CYprus POsitioning System), a network of seven permanent GNSS stations has been operating since 2008, under the responsibility of the Department of Lands and Surveys. The continuous flow of positioning data collected over this network, offers the required information to investigate the behavior of the crustal deformation field of Cyprus using GNSS sensors for the first time. This paper presents the results of a multi-year analysis (11/2011–01/2017) of daily GNSS data and provides inferences of linear and nonlinear deforming signals into the position time series of the network stations. Specifically, 3D station velocities and seasonal periodic displacements are jointly estimated and presented via a data stacking approach with respect to the IGb08 reference frame.

scholarly journals GNSS-based Orbital Filter for Earth Moon Transfer Orbits

2015 ◽  
Vol 69 (4) ◽  
pp. 745-764 ◽  
Author(s):  
Vincenzo Capuano ◽  
Francesco Basile ◽  
Cyril Botteron ◽  
Pierre- André Farine
Keyword(s):  
Model Simulation ◽  
Global Navigation Satellite Systems ◽  
Navigation Systems ◽  
Satellite Systems ◽  
Transfer Orbits ◽  
Low Earth Orbits ◽  
Global Navigation Satellite ◽  
Navigation Accuracy ◽  
Earth Orbits ◽  
Gnss Observations

Numerous applications, not only Earth-based, but also space-based, have strengthened the interest of the international scientific community in using Global Navigation Satellite Systems (GNSSs) as navigation systems for space missions that require good accuracy and low operating costs. Indeed, already successfully used in Low Earth Orbits (LEOs), GNSS-based navigation systems can maximise the autonomy of a spacecraft while reducing the burden and the costs of ground operations. That is why GNSS is also attractive for applications in higher Earth orbits up to the Moon, such as in Moon Transfer Orbits (MTOs). However, the higher the altitude the receiver is above the GNSS constellations, the poorer and the weaker are the relative geometry and the received signal powers, respectively, leading to a significant navigation accuracy reduction. In order to improve the achievable GNSS performance in MTOs, we consider in this paper an adaptive orbital filter that fuses the GNSS observations with an orbital forces model. Simulation results show a navigation accuracy significantly higher than that attainable individually by a standalone GNSS receiver or by means of a pure orbital propagation.

scholarly journals New GNSS tomography of the atmosphere method – proposal and testing

2012 ◽  
Vol 9 ◽  
pp. 63-76 ◽  
Author(s):  
Michal Kačmařík ◽  
Lukáš Rapant
Keyword(s):  
Water Vapour ◽  
Theoretical Concept ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Gnss Meteorology ◽  
Gnss Receivers ◽  
Tomography Method ◽  
Gnss Measurements ◽  
Global Navigation Satellite

Paper is focused on GNSS meteorology which is generally used for the determination of water vapour distribution in the atmosphere from GNSS measurements. Water vapour in the atmosphere is an important parameter which influences the state and development of the weather. At first, the paper presents basics of the GNSS meteorology and tomography of the atmosphere and subsequently introduces a new GNSS tomography method which doesn't require an extensive network of GNSS receivers, but uses only a few receivers situated in a line. After a theoretical concept describing this method and used mathematical background, the results from a real experiment are shown and discussed. Unfortunately the results indicate that presented method is not able to provide credible outputs. Possibly the main problem lies in an insufficient number of available signals from current global navigation satellite systems (GPS and GLONASS) where the improvement could be expected after the start of Galileo and Compass. Potential ways how to improve the results without increasing the number of satellites are outlined in the last section.

The Potential Impact of GNSS/INS Integration on Maritime Navigation

2008 ◽  
Vol 61 (2) ◽  
pp. 221-237 ◽  
Author(s):  
Terry Moore ◽  
Chris Hill ◽  
Andy Norris ◽  
Chris Hide ◽  
David Park ◽  
...  
Keyword(s):  
Field Trials ◽  
Global Navigation Satellite Systems ◽  
Navigation Systems ◽  
Inertial Navigation Systems ◽  
Satellite Systems ◽  
Time Period ◽  
Maritime Navigation ◽  
The Uk ◽  
Global Navigation Satellite ◽  
The Impact

A version of this paper was presented at ENC-GNSS 2007, Geneva. Its reproduction was kindly authorised by the ENC-GNSS 07 Paper Selection Committee.The General Lighthouse Authorities of the UK & Ireland commissioned an assessment of the impact that the integration of Global Navigation Satellite Systems (GNSS) with Inertial Navigation Systems (INS) would have on the aids to navigation (AtoN) services currently provided, and those to be provided in the future. There is concern about the vulnerability of GNSS, and the provision of complementary and backup systems is seen to be of great importance. The integration of INS could provide an independent and self-contained navigation system, for a limited time period, invulnerable to external intentional or unintentional interference, or the influences of changes in national policies. The study included an analysis of the potential use of GNSS-INS in three of the four phases of a vessel's voyage: coastal, port approach and docking. The project consisted of a technology assessment, looking at the different inertial technologies that might be suitable for each phase. This was followed by a technology proving stage, evaluating suitable equipment using simulation and field trials to prove that the claimed performance could be achieved in practice. The final stage of the project was to assess the effects of the availability of such systems on existing and planned aids to navigation services.

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.

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