Advanced Integration of GNSS and External Sensors for Autonomous Mobility Applications

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On the Use of an Ultra-Tight Integration for Robust Navigation in Jammed Scenarios

Peer reviewe

Optimized design of next-generation multiplexing schemes for GNSSs

Multilevel and multicarrier component signals are now common in many Global Navigation Satellite Systems challenging the employed multiplexing method that needs to be more flexible and powerful. In this work, we demonstrate how, by acting on two parameters of the digital baseband representation of component signals (the sampling frequency and the central frequency of the baseband complex envelope), it is possible to optimize the performance of the multiplexer, while still obtaining a composite signal that fulfills the required system constraints

SaPPART Guidelines: Assessment of positioning performance in ITS applications

This deliverable, entitled guidelines, is the third outcome of SaPPART COST Action, a European network of scientists and stakeholders that aims to promote smart use of GNSS technology in the field of intelligent road transport and mobility. It discusses the performance assessment of the GNSS-based Positioning terminals (GBPT), which is generally under the responsibility of the system integrators in the road market of GNSS. The aim of this document is to provide guidelines for generic test procedures for the evaluation of GBPT performance, either by field tests, simulations or their combination, compliant with the concepts and the definitions already established in the SaPPART White Paper (TMI 1) and Handbook (TMI 2). The document is intended to provide the reader with a helpful tool for planning the GBPT testing procedures by both discussing the testing in general and by providing some detailed practical information

Benefits and Limitations of the Record and Replay Approach for GNSS Receiver Performance Assessment in Harsh Scenarios

Global navigation satellite systems play a significant role in the development of intelligent transport systems, where the estimation of the vehicle’s position is a key element. However, in strongly constrained environments such as city centers, the definition of quality metrics and the assessment of positioning performances are challenges to be addressed. Due to the variability of different urban scenarios, the modeling of the dynamics as well as the architecture of the positioning platform, which might embed other sensors and aiding means to the GNSS unit, make it hard to define unambiguous positioning metrics. Performance assessment through analytical models and simulators can be ineffective in terms of cost, complexity, and general validity and scalability of the results. This paper shows how a record and replay approach can be an efficient solution to grant fidelity to a realistic scenario. This work discusses advantages and disadvantages with emphasis on the case study of harsh scenarios. Such an approach requires proper data collections that allow the replay phase to test the GNSS-based positioning terminals. This paper presents the results obtained on a set of field tests related to different scenarios, selected as representative for the key performance indicators assessment

Benefits and Limitations of the Record and Replay Approach for GNSS Receiver Performance Assessment in Harsh Scenarios

Global navigation satellite systems play a significant role in the development of intelligent transport systems, where the estimation of the vehicle’s position is a key element. How-ever, in strongly constrained environments such as city centers, the definition of quality metrics and the assessment of positioning performances are challenges to be addressed. Due to the variability of different urban scenarios, the model-ing of the dynamics as well as the architecture of the posi-tioning platform, which might embed other sensors and aid-ing means to the GNSS unit, make it hard to define unam-biguous positioning metrics. Performance assessment through analytical models and simulators can be ineffective in terms of cost, complexity, and general validity and scala-bility of the results. This paper shows how a record and replay approach can be an efficient solution to grant fidelity to a realistic scenario. This work discusses advantages and disadvantages with emphasis on the case study of harsh scenarios. Such an approach requires proper data collec-tions that allow the replay phase to test the GNSS-based positioning terminals. This paper presents the results ob-tained on a set of field tests related to different scenarios, selected as representative for the key performance indica-tors assessment

GNSS/INS/Visual Deeply Coupled Integration: Preliminary Investigation on Dynamic Jammed Datasets

As the Global Satellite Navigation Systems (GNSS) signals are received and processed by the GNSS receivers with an extremely low power, they are vulnerable to non-intentional and intentional interference. In particular, the intentional transmission of Radio Frequency interference, known as jamming, can completely prevent the operation of GNSS receivers. The integration of measurements from multiple sensors with complementary error characteristics offers a possible countermeasure against jamming and, therefore, it can provide a position solution that has sufficient accuracy for the applications. This paper shows how a Deeply Coupled (DC) integration of GNSS with Inertial Navigation Systems (INS) and visual sensors enhances the robustness of the navigation system in presence of jamming. In particular, the effect of DC integration for jamming mitigation is investigated for a dynamic scenario where jamming signals have been added to a pre-recorded GNSS scenario by using the record and replay approach, emulating different interference levels. The results presented in this paper show that the deep coupling of GNSS with INS and visual sensors can sustain the navigation in presence of high power jamming, although such a strong interference completely masks the GNSS signal denying the navigation of a GNSS stand-alone system. Moreover, the test procedures suitability of the record and replay approach for the jamming scenario generation and combination with real datasets are discussed and analyze

A Collaborative Method for GNSS-based Inter-Agent Range Estimation and Hybrid Positioning Algorithm in Harsh Environment

Harsh environment is the main impediment to GNSS service availability due to the obstruction of line-of-sight between the satellites and the receiver. A well-known countermeasure to this issue is the exploitation of additional measurements integrated with the GNSS solution, addressed to assure the continuity of service or to improve the positioning performance. Modern communication networks (i.e. 5G/LTE or VANET) provide limited delays allowing a quasi-real-time data transfers suitable for positioning applications. This work relies on such a kind of low-latency communication network, to cooperatively extract the pseudo-distance between pairs of agents equipped with Global Navigation Satellite Systems receivers, thus adapting the positioning algorithm to exploit the additional navigation data. The simultaneous observation of shared satellites allows to estimate the Non-Line-Of-Sight Inter-Agent Range and pseudo-Inter-Agent Range. This is pursued with the aim to guarantee a continuous position availability to the subset of receivers that are experiencing a GNSS positioning failure due to the limited visibility of the constellation, as it may happen in urban scenarios. In this context, the effectiveness of the hybrid cooperative positioning, smoothed with a properly designed Kalman Filter, is verified

The Record and Replay Approach for GNSS Receiver Performance Assessment in Road Environment

Nowadays the concept of smart transport, that exploits Intelligent Transport Systems (ITS) technology, plays a fundamental role in our society. The Global Navigation Satellite Systems (GNSS) have significant potential in the development of ITS where the estimation of the vehicle's position represents a key role. However, in strongly constrained environments, such as city centers, the definition of positioning performances is a challenge due to the variability of the different urban scenarios, the modeling of the dynamics as well as the architecture of the positioning platform, which might embed other sensors and aiding means to the GNSS unit. Moreover, the performance metrics of interest are not just position and speed but metrics related to the integrity/reliability concept, properly defined for the road environment. These performance metrics are becoming of paramount interest, as safety-critical application emerging, and have to be assessed. This framework asks for a deep understanding by the ITS sector of the achievable performance by GNSS systems in the different scenarios for automotive. In fact, positioning is taken as a fully reliable and accurate information, based on which more and more automated driving operations are performed. For this reason, the need of standardized performance metrics for GNSS-Based Positioning Terminal (GBPT) and the associated performance assessment procedures and scenarios assume considerable importance. The main focus of the paper is to introduce a performance evaluation procedure based on a record and replay approach able to represent meaningful and realistic scenarios. This approach requires proper data collections that allow the replay phase and data postprocessing to test the GBPT performance. The paper presents also some results obtained on a set of field tests related to different scenarios, selected as representative of reference scenarios for the Key Performance Indicators (KPIs) assessment