scholarly journals LiDAR-Based GNSS Denied Localization for Autonomous Racing Cars

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3992 ◽  
Author(s):  
Federico Massa ◽  
Luca Bonamini ◽  
Alessandro Settimi ◽  
Lucia Pallottino ◽  
Danilo Caporale
Keyword(s):  
State Of The Art ◽  
Human Mobility ◽  
A Priori ◽  
Global Navigation Satellite Systems ◽  
High Rate ◽  
Human Environment ◽  
Localization Accuracy ◽  
Satellite Systems ◽  
Planning And Control ◽  
Global Navigation Satellite

Self driving vehicles promise to bring one of the greatest technological and social revolutions of the next decade for their potential to drastically change human mobility and goods transportation, in particular regarding efficiency and safety. Autonomous racing provides very similar technological issues while allowing for more extreme conditions in a safe human environment. While the software stack driving the racing car consists of several modules, in this paper we focus on the localization problem, which provides as output the estimated pose of the vehicle needed by the planning and control modules. When driving near the friction limits, localization accuracy is critical as small errors can induce large errors in control due to the nonlinearities of the vehicle’s dynamic model. In this paper, we present a localization architecture for a racing car that does not rely on Global Navigation Satellite Systems (GNSS). It consists of two multi-rate Extended Kalman Filters and an extension of a state-of-the-art laser-based Monte Carlo localization approach that exploits some a priori knowledge of the environment and context. We first compare the proposed method with a solution based on a widely employed state-of-the-art implementation, outlining its strengths and limitations within our experimental scenario. The architecture is then tested both in simulation and experimentally on a full-scale autonomous electric racing car during an event of Roborace Season Alpha. The results show its robustness in avoiding the robot kidnapping problem typical of particle filters localization methods, while providing a smooth and high rate pose estimate. The pose error distribution depends on the car velocity, and spans on average from 0.1 m (at 60 km/h) to 1.48 m (at 200 km/h) laterally and from 1.9 m (at 100 km/h) to 4.92 m (at 200 km/h) longitudinally.

scholarly journals TRANSLATING AERIAL IMAGES INTO STREET-MAP-LIKE REPRESENTATIONS FOR VISUAL SELF-LOCALIZATION OF UAVS

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 575-580 ◽  
Author(s):  
M. Schleiss
Keyword(s):  
Global Positioning System ◽  
Global Navigation Satellite Systems ◽  
Aerial Imagery ◽  
Aerial Images ◽  
Visual Localization ◽  
Localization Accuracy ◽  
Satellite Systems ◽  
Global Positioning ◽  
Reference Map ◽  
Global Navigation Satellite

<p><strong>Abstract.</strong> Unmanned aerial vehicles (UAVs) rely on global navigation satellite systems (GNSS) like the Global Positioning System (GPS) for navigation but GNSS signals can be easily jammed. Therefore, we propose a visual localization method that uses a camera and data from Open Street Maps in order to replace GNSS. First, the aerial imagery from the onboard camera is translated into a map-like representation. Then we match it with a reference map to infer the vehicle’s position. An experiment over a typical sized mission area shows localization accuracy close to commercial GPS. Compared to previous methods ours is applicable to a broader range of scenarios. It can incorporate multiple types of landmarks like roads and buildings and it outputs absolute positions with higher frequency and confidence and can be used at altitudes typical for commercial UAVs. Our results show that the proposed method can serve as a backup to GNSS systems where suitable landmarks are available.</p>

scholarly journals The Rapid and Steady Mass Loss of the Patagonian Icefields throughout the GRACE Era: 2002–2017

2019 ◽  
Vol 11 (8) ◽  
pp. 909 ◽  
Author(s):  
Andreas Richter ◽  
Andreas Groh ◽  
Martin Horwath ◽  
Erik Ivins ◽  
Eric Marderwald ◽  
...  
Keyword(s):  
Time Series ◽  
Mass Loss ◽  
A Priori ◽  
Global Navigation Satellite Systems ◽  
Mass Change ◽  
Satellite Systems ◽  
Isostatic Adjustment ◽  
Global Navigation Satellite ◽  
Gravity Recovery ◽  
The Antarctic

We use the complete gravity recovery and climate experiment (GRACE) Level-2 monthly time series to derive the ice mass changes of the Patagonian Icefields (Southern Andes). The glacial isostatic adjustment is accounted for by a regional model that is constrained by global navigation satellite systems (GNSS) uplift observations. Further corrections are applied concerning the effect of mass variations in the ocean, in the continental water storage, and of the Antarctic ice sheet. The 161 monthly GRACE gravity field solutions are inverted in the spatial domain through the adjustment of scaling factors applied to a-priori ice mass change patterns based on published remote sensing results for the Southern and Northern Patagonian Icefields, respectively. We infer an ice mass change rate of −24.4 ± 4.7 Gt/a for the Patagonian Icefields between April 2002 and June 2017, which corresponds to a contribution to the eustatic sea level rise of 0.067 ± 0.013 mm/a. Our time series of monthly ice mass changes reveals no indication for an acceleration in ice mass loss. We find indications that the Northern Patagonian Icefield contributes more to the integral ice loss than previously assumed.

Application of Computer Modelling in Adaptive Compensation of Interferences on Global Navigation Satellite Systems

2019 ◽  
pp. 339-380 ◽  
Author(s):  
Valerian Shvets ◽  
Svitlana Ilnytska ◽  
Oleksandr Kutsenko
Keyword(s):  
A Priori ◽  
Inverse Correlation ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
A Priori Information ◽  
Satellite Systems ◽  
Useful Signal ◽  
Global Navigation ◽  
Priori Information ◽  
Global Navigation Satellite

Modern society is characterized by the increased use of global navigation satellite systems (GNSS), which is inseparably linked with the interference immunity ensurance. The most effective way to protect against interferences is an introduction into the receiver structure of adaptive interference compensators. However, the most of proposed methods have been designed for radiolocation and communication and use a priori information about the transmitted signal. Since as structure of GNSS signal differs from the radar and communication systems, GNSS does not know the time-frequency structure of the useful signal in advance, which excludes the possibility of using a number of widely known methods. In this chapter, the authors propose a method, which does not use a priori information about a useful signal, and a new direct method for calculating the inverse correlation matrix of interference in adaptive antennas of interferences compensators.

scholarly journals Review of the state-of-the-art and future prospects of the ground-based GNSS meteorology in Europe

2016 ◽  
Author(s):  
Guergana Guerova ◽  
Jonathan Jones ◽  
Jan Dousa ◽  
Galina Dick ◽  
Siebren de Haan ◽  
...  
Keyword(s):  
State Of The Art ◽  
Weather Prediction ◽  
The State ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Satellite Systems ◽  
Climate Monitoring ◽  
Gnss Meteorology ◽  
Global Navigation Satellite ◽  
Gnss Processing

Abstract. Global Navigation Satellite Systems (GNSS) have revolutionised positioning, navigation, and timing, becoming a common part of our everyday life. Aside from these well-known civilian and commercial applications, GNSS is now an established atmospheric observing system, which can accurately sense water vapour, the most abundant greenhouse gas, accounting for 60–70 % of atmospheric warming. In Europe, the application of GNSS in meteorology started roughly two decades ago and today it is a well-established research field. This review covers the state-of-the-art in GNSS meteorology in Europe. Discussed are the advances in GNSS processing for derivation of tropospheric products, application of GNSS tropospheric products in operational weather prediction and application of GNSS tropospheric products for climate monitoring. Reviewed are the GNSS processing techniques and tropospheric products. Given is a summary of the use of the products for validation and impact studies with operational Numerical Weather Prediction (NWP) models as well as very short weather prediction (nowcasting) case studies. Climate research with GNSS is an emerging field of research, the studies so far have been limited to comparison with the climate models and derivation of trends. More than 15 years of GNSS meteorology in Europe has already achieved outstanding cooperation between the atmospheric and geodetic communities. It is now feasible to develop next-generation GNSS tropospheric products and applications that can enhance the quality of weather forecasts and climate monitoring. This work is carried out within COST Action ES1206 "Advanced Global Navigation Satellite Systems tropospheric products for monitoring Severe Weather Events and Climate" (GNSS4SWEC, http://gnss4swec.knmi.nl ).

scholarly journals Review of the state of the art and future prospects of the ground-based GNSS meteorology in Europe

2016 ◽  
Vol 9 (11) ◽  
pp. 5385-5406 ◽  
Author(s):  
Guergana Guerova ◽  
Jonathan Jones ◽  
Jan Douša ◽  
Galina Dick ◽  
Siebren de Haan ◽  
...  
Keyword(s):  
State Of The Art ◽  
Weather Prediction ◽  
The State ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Satellite Systems ◽  
Climate Monitoring ◽  
Gnss Meteorology ◽  
Global Navigation Satellite ◽  
Gnss Processing

Abstract. Global navigation satellite systems (GNSSs) have revolutionised positioning, navigation, and timing, becoming a common part of our everyday life. Aside from these well-known civilian and commercial applications, GNSS is now an established atmospheric observing system, which can accurately sense water vapour, the most abundant greenhouse gas, accounting for 60–70 % of atmospheric warming. In Europe, the application of GNSS in meteorology started roughly two decades ago, and today it is a well-established field in both research and operation. This review covers the state of the art in GNSS meteorology in Europe. The advances in GNSS processing for derivation of tropospheric products, application of GNSS tropospheric products in operational weather prediction and application of GNSS tropospheric products for climate monitoring are discussed. The GNSS processing techniques and tropospheric products are reviewed. A summary of the use of the products for validation and impact studies with operational numerical weather prediction (NWP) models as well as very short weather prediction (nowcasting) case studies is given. Climate research with GNSSs is an emerging field of research, but the studies so far have been limited to comparison with climate models and derivation of trends. More than 15 years of GNSS meteorology in Europe has already achieved outstanding cooperation between the atmospheric and geodetic communities. It is now feasible to develop next-generation GNSS tropospheric products and applications that can enhance the quality of weather forecasts and climate monitoring. This work is carried out within COST Action ES1206 advanced global navigation satellite systems tropospheric products for monitoring severe weather events and climate (GNSS4SWEC, http://gnss4swec.knmi.nl).

scholarly journals Intersystem Bias in GPS, GLONASS, Galileo, BDS-3, and BDS-2 Integrated SPP: Characteristics and Performance Enhancement as a Priori Constraints

2021 ◽  
Vol 13 (22) ◽  
pp. 4650
Author(s):  
Lin Pan ◽  
Zhehao Zhang ◽  
Wenkun Yu ◽  
Wujiao Dai
Keyword(s):  
Performance Enhancement ◽  
Low Cost ◽  
Single Point ◽  
A Priori ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Term Stability ◽  
Long Term Stability ◽  
And Performance ◽  
Global Navigation Satellite

Global navigation satellite systems (GNSSs) have been booming in recent years, and the space segment of all four of the GNSSs, including BDS (BDS-3/BDS-2), Galileo, GPS, and GLONASS, has almost been fully deployed at present. The single point positioning (SPP) technology, which is widely used in satellite navigation and low-accuracy positioning, can benefit from the multi-GNSS integration, but the additional intersystem bias (ISB) parameters should be introduced to ensure the compatibility among different GNSSs. In this study, the ISB estimates derived from four-system integrated SPP are carefully characterized, and the performance enhancement attributed to a priori ISB constraints by prediction for position solutions under open sky and constrained visibility environments is rigorously evaluated. The results indicate that the ISB between BDS-3 and BDS-2 cannot be ignored. The daily ISBs show step changes when encountering the replacement of receiver types, while it is not the case for the receiver firmware versions. The daily ISBs are roughly consistent for the stations equipped with the same type of receivers. The short-term stability of epochwise ISBs for GLONASS, Galileo, BDS-2, and BDS-3 with respect to GPS can be 2.335, 1.262, 1.741, and 1.532 ns, respectively, whereas the corresponding long-term stability for daily ISBs can be 1.258, 1.288, 2.713, and 2.566 ns, respectively. The single-day prediction accuracy of daily ISBs for GLONASS, Galileo, BDS-2, and BDS-3 with respect to GPS can be 1.055, 0.640, 1.242, and 0.849 ns, respectively. The improvements on positioning accuracy after introducing a priori ISB constraints can be over 20% at an elevation mask of 40° and 50° with a time span of ISB prediction of a day. As to the availability, it is only 64.0% for traditional four-system SPP under a cutoff elevation of 50°, while the corresponding availability is increased to approximately 90.0% after considering a priori ISB constraints. For completeness, the characteristics of ISBs estimated with the low-cost u-blox M8T receiver and the Xiaomi Mi8 smartphone as well as the contribution of a priori ISB constraints to the multisystem SPP solutions with these devices are also investigated.

scholarly journals Real-Time High-Rate GNSS Displacements: Performance Demonstration during the 2019 Ridgecrest, California, Earthquakes

2019 ◽  
Vol 91 (4) ◽  
pp. 1943-1951 ◽  
Author(s):  
Diego Melgar ◽  
Timothy I. Melbourne ◽  
Brendan W. Crowell ◽  
Jianghui Geng ◽  
Walter Szeliga ◽  
...  
Keyword(s):  
Real Time ◽  
Inertial Sensors ◽  
Global Navigation Satellite Systems ◽  
High Rate ◽  
Source Characterization ◽  
Satellite Systems ◽  
Earthquake Sources ◽  
Initial Source ◽  
Global Navigation Satellite ◽  
Good Agreement

Abstract Traditional real-time (RT) seismology has relied on inertial sensors to characterize ground motions and earthquake sources, particularly for hazards applications such as warning systems. In the past decade, a revolution in high-rate, RT Global Navigation Satellite Systems (GNSS) displacement has provided a new source of data to augment traditional measurement devices. The Ridgecrest, California, earthquake sequence in 2019 provided one of the most complete recordings of RT-GNSS displacements to date, helping aid in an initial source characterization over the first few days. In this article, we analyze and make available the archived RT displacement streams and compare their performance to postprocessed results, which we also provide. We find good agreement for all stations showing a noticeable signal. This demonstrates that simple modeling in RT, such as peak ground displacement scaling, would be practically identical to postprocessed results. Similarly, we find good agreement across the full spectral range, from the coseismic offsets (∼0  Hz) to the Nyquist frequency. We also find low latency between the measurement acquisition at the field site and the position calculation at the data center. In aggregate, the performance during the Ridgecrest earthquakes is strong evidence of the viability and usefulness of RT-GNSS as a monitoring tool.

scholarly journals Methodology for Simulating 5G and GNSS High-Accuracy Positioning

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3220 ◽  
Author(s):  
José del Peral-Rosado ◽  
Jani Saloranta ◽  
Giuseppe Destino ◽  
José López-Salcedo ◽  
Gonzalo Seco-Granados
Keyword(s):  
High Accuracy ◽  
Urban Environments ◽  
Global Navigation Satellite Systems ◽  
Base Stations ◽  
Line Of Sight ◽  
Millimetre Wave ◽  
Localization Accuracy ◽  
Satellite Systems ◽  
Hybrid Positioning ◽  
Global Navigation Satellite

This paper focuses on the exploitation of fifth generation (5G) centimetre-wave (cmWave) and millimetre-wave (mmWave) transmissions for high-accuracy positioning, in order to complement the availability of Global Navigation Satellite Systems (GNSS) in harsh environments, such as urban canyons. Our goal is to present a representative methodology to simulate and assess their hybrid positioning capabilities over outdoor urban, suburban and rural scenarios. A novel scenario definition is proposed to integrate the network density of 5G deployments with the visibility masks of GNSS satellites, which helps to generate correlated scenarios of both technologies. Then, a generic and representative modeling of the 5G and GNSS observables is presented for snapshot positioning, which is suitable for standard protocols. The simulations results indicate that GNSS drives the achievable accuracy of its hybridisation with 5G cmWave, because non-line-of-sight (NLoS) conditions can limit the cmWave localization accuracy to around 20 m. The 5G performance is significantly improved with the use of mmWave positioning with dominant line-of-sight (LoS) conditions, which can even achieve sub-meter localization with one or more base stations. Therefore, these results show that NLoS conditions need to be weighted in 5G localization, in order to complement and outperform GNSS positioning over urban environments.

scholarly journals Development of a Submillimetric GNSS-Based Distance Meter for Length Metrology

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1145
Author(s):  
Luis García-Asenjo ◽  
Sergio Baselga ◽  
Chris Atkins ◽  
Pascual Garrigues
Keyword(s):  
State Of The Art ◽  
Global Navigation Satellite Systems ◽  
Absolute Distance ◽  
Research Projects ◽  
New Techniques ◽  
Distance Determination ◽  
Satellite Systems ◽  
Unit Of Length ◽  
Wave Laser ◽  
Global Navigation Satellite

Absolute distance determination in the open air with an uncertainty of a few tenths of a millimetre is increasingly required in many applications that involve high precision geodetic metrology. No matter the technique used to measure, the resulting distances must be proven consistent with the unit of length (SI-metre) as realized in the outdoor facilities traditionally used in length metrology, which are also known as calibration baselines of reference. The current calibration baselines of reference have distances in the range of 10 to 1000 m, but at present there is no solution on the market to provide distances with submillimetric precision in that range. Consequently, new techniques such as multi-wave interferometry, two-wave laser telemeters or laser trackers are being developed. A possible alternative to those sophisticated and expensive techniques is the use of widely used Global Navigation Satellite Systems (GNSS) in order to provide a GNSS-Based Distance Meter (GBDM). The use of a GBDM as a potential technique for length metrology has been thoroughly analysed in several European research projects by using the state-of-the-art geodetic software, such as Bernese 5.2, but no definite conclusions have been drawn and some metrological questions are considered still open. In this paper, we describe a dedicated approach to build up a submillimetric GBDM able to be applied in the current calibration baselines of reference, as well as possible methods to cope with the multipath error of the GNSS signals which is the major limitation for the practical uptaking of the technique in metrology. The accuracy of the proposed approach has been tested following the length metrology standards in four experiments carried out in the Universitat Politècnica de València (UPV). The results demonstrate that the proposed GBDM can provide an accuracy of a few tenths of a millimetre in the current calibration baselines of reference.

Sign in / Sign up

Export Citation Format

Share Document