39 research outputs found
Robust Low-Cost Navigation Solutions for Service Robotics
No full textL'abstract è presente nell'allegato / the abstract is in the attachmen
Assessment of positioning performances in Italy from GPS, BDS and GLONASS constellations
No full textThe use of multiple GNSS constellations has been beneficiary to positioning performances and reliability in recent times, especially in low cost mass-market setups. Along with GPS and GLONASS, GALILEO and BDS are the other two constellations aiming for global coverage. With ample research demonstrating the benefits of GALILEO in the European region, there has been a lack of study to demonstrate the performance of BDS in Europe, especially with mass-market GNSS receivers. This study makes a comparison of the performances between the combined GPS-GLONASS and GPS-BDS constellations in Europe with such receivers. Static open sky and kinematic urban environment tests are performed with two GNSS receivers as master and rover at short baselines and the RTK and double differenced post processed solutions are analyzed. The pros and cons of both the constellation choices is demonstrated in terms of fixed solution accuracies, percentage of false fixes, time to first fix for RTK and float solution accuracies for post processed measurements. Centimeter level accuracy is achieved in both constellations for static positioning with GPS-BDS combination having a slightly better performance in comparable conditions and smaller intervals. GPS-GLONASS performed slightly better for longer intervals due to the current inconsistent availability of BDS satellites. Even if the static tests have shown a better performance of GPS-BDS combination, the kinematic results show that there are no significant differences between the two tested configurations. Keywords: GNSS, BDS, GLONASS, NRTK positioning, Accurac
A Proof-of-concept of Cooperative DGNSS for UAV/UGV Navigation
No full textService robotics is becoming a reality in many aspects of daily life due to the successful merger of several enabling technologies from the fields of Information and Communication Technologies. The growing availability of mass market products is also driving innovation towards automation in several civil and scientific areas. Specific applications such as precision farming, surveying, rescue operations and remote exploration can benefit from such modern and affordable robots, thus helping humans in work-related or daily life. To support such a new generation of service robots and vehicles, navigation capabilities play a fundamental role in mission planning and on-field activities. In parallel, recent developments of ultra-low cost embedded Global Navigation Satellite System (GNSS), such as in AndroidTM smartphones has enabled affordable Location Based Services (LBS) applications and provided an impetus to research into low cost navigation solutions. Modern smartphones come with an advantage of having a ubiquitous network infrastructure with ease of developing interconnected applications and integrated proprioceptive and exteroceptive sensors. Within the framework of precision agriculture promoted by the Politecnico di Torino Interdepartmental Centre for Service Robotics, this work investigates a low-cost navigation strategy for an Unmanned Ground Vehicle (UGV) – Unmanned Aerial Vehicle (UAV) paradigm exploiting a collaborative ranging technique based on Differential GNSS (DGNSS) approach applied on raw measurements exchanged between AndroidTM smartphones
On the Cooperative Ranging between Android Smartphones Sharing Raw GNSS Measurements
No full textThe combination of ubiquitous network infrastructure and the high density of powerful, interconnected mobile devices in urban areas is driving the rise of smart cities. In parallel, the availability of ultra-low cost embedded Global Navigation Satellite System (GNSS) has enabled several affordable Location Based Services (LBS). New chipsets supporting dual frequency and multi-constellation GNSS signals are reducing the gap between high grade and mass market device performances. Among these devices, Android smartphones represent valuable and affordable tools for many LBS in the early advent of Intelligent Transportation Systems and smart vehicular navigation. Mobile networks natively provide a multiplicity of connected devices, thus enabling a family of applications demanding for a communication channel among GNSS receivers. This paper experimentally validates a collaborative technique based on the exchange of raw GNSS measurements to retrieve the relative range between Android smartphones. Additionally, a framework for the exchange of data between smartphones is provided, allowing the application of such a computationally-efficient ranging methodology in a network of low cost mobile devices within a smart city framework
Evaluating Smartphone RTK Performance with Low-Cost GNSS Receivers and Correction Services in Traditional and Low-Cost GNSS Networks
No full textThe emergence of low-cost GNSS hardware and affordable RTK correction services has made high-precision positioning more accessible. While prior studies have investigated RTK capabilities using smartphones, most rely on professional geodetic infrastructures. This study shifts the focus toward evaluating smartphone-based RTK positioning within low-cost GNSS networks and comparing the performance against traditional geodetic network setups. The research investigates two main configurations: (1) a smartphone functioning as an RTK rover within a low-cost GNSS network, using a low-cost base station and publicly available or inexpensive correction services, and (2) the same smartphone setup operating within a traditional geodetic network with high-grade base stations. The study aims to assess the viability of smartphones as RTK rovers in low cost networks, exploring metrics such as horizontal and vertical positioning accuracy, fix reliability, initialization time, and system responsiveness. Preliminary findings suggest that smartphones integrated with low-cost GNSS receivers can deliver sub-meter accuracy under favorable conditions, though some trade-offs are noted when compared with geodetic-grade infrastructure. The study emphasizes the potential of cost-effective RTK configurations for practical applications where high precision is required. By comparing performance across traditional and low-cost network configurations, this research demonstrates the increasing potential of using smartphones and low-cost GNSS systems to make high-precision positioning more accessible
A controlled-environment quality assessment of android GNSS raw measurements
No full textRaw Global Navigation Satellite System (GNSS) measurements have been available since 2016 in select Android smartphones. The availability of such observations allows smartphones users, in principle, to significantly improve the quality of GNSS-based positioning by applying customized and advanced positioning algorithms. However, the quality of such measurements is poor, mainly because of the low quality of smartphone hardware components and the non ideal environment in which phones are typically used. To overcome this problem and to separate the contribution of the hardware components and signal quality, dedicated test campaigns were carried out in a real environment and in a controlled-environment anechoic chamber using several different Android models. In addition, signal-processing techniques aimed at increasing the accuracy and precision of the solution were employed. Results show that the quality of the data captured in the anechoic chamber was significantly better than in real conditions. Furthermore, such analysis allows to underline certain phenomena in smartphones, such as the duty cycle, and to test the validity of anechoic environments for Android raw measurements
GNSS Anti-Spoofing Defense Based on Cooperative Positioning
No full textRadio navigation is of utmost importance in several application fields. Nowadays, many civil and professional applications massively rely on the Global Navigation Satellite System (GNSS) and related technologies to accurately estimate position and time. Existing GNSS-based systems are threatened by malicious attacks among which spoofing and meaconing constitute severe challenges to the receiver. Several of such GNSS systems constitute mass market applications and devices, and a threat to the GNSS receiver could have cascading effects at application levels and for interconnected systems. Networked GNSS receivers are in general ubiquitous because any receiver embedded in a complex system such as a smart device or smart connected cars can exploit network connectivity. This novel generation of valuable-performance GNSS receivers are prone both to standard RF spoofing attacks and to cyber-attacks conceived to hijack complex network based services such as DGNSS-based cooperative positioning. By means of a set of experimental tests, this paper highlights possible metrics to be checked to identify malicious attacks to the positioning and navigation systems in mass market connected devices. The network-based exchange of GNSS data such as GNSS raw measurements recently disclosed in Android smart devices is conceived in this work to offer the possibility to compare or combine such metrics to better identifies spoofing and meaconing attacks
Fast Deformation Detection with mass market GNSS time differential observations and use of baseline constraints
No full textGlobal Navigation Satellite Systems (GNSS) technology has been a consistent alternative to monitor and detect structural deformation using geodetic receivers. The role of low cost GNSS receivers have been explored in recent years and this study proposes the use of two such receivers as master and rover respectively to detect fast deformations. Single differenced observations of C/A code and L1 GPS carrier phase are differenced in time to obtain positions and velocities of a rover receiver and the performance of these observations in deformation detection is seen. Additional constraints of baseline between the master and rover are shown to improve the performance with successful detection of de?ections through rover velocity readings. Continuing previous research, another door for the use of low cost receivers to reliably detect deformations is opened and the real time use of such methodology can be explored
Assessment of the Vulnerability to Spoofing Attacks of GNSS Receivers Integrated in Consumer Devices
No full textIn this paper, we investigate the effects of spoofing attacks on the mass-market positioning and navigation units
integrated in modern day AndroidTM smartphones. In order to operate spoofing in a real environment, we signed and implemented a portable, configurable, low-cost GPS spoofer exploiting a software-defined radio (SDR) implementation and a low-cost front-end. Such a tool has been exploited to set up a test campaign trying to mislead the Position, Velocity and Time computation of different AndroidTM smartphones. The effects of such simplistic spoofing attack on the smartphone GNSS has been assessed observing raw measurements and the evaluated positions and time. The main findings of this work showed that modern AndroidTM devices have a remarkable resilience to simplistic spoofing attacks, highlighting in parallel further potential weaknesses to be protected by means of practical defence mechanisms and countermeasures to spoofing
The idea of the political, reconfiguring sovereignty and exception: Analysing theoretical perspectives of Carl Schmitt and Giorgio Agamben
No full textThe idea of the political, reconfiguring sovereignty and exception: Analysing theoretical perspectives of Carl Schmitt and Giorgio Agamben
Author / Authors : Meenakshi Gogoi
Page no. 69-78
Discipline : Political Science/Polity/ Democratic studies
Script/language : Roman/English
Category : Research paper
Keywords: Political, Sovereignty, Exception, Democracy, Rule of Law
