scholarly journals NaviSoC: High-Accuracy Low-Power GNSS SoC with an Integrated Application Processor

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1069 ◽  
Author(s):  
Tomasz Borejko ◽  
Krzysztof Marcinek ◽  
Krzysztof Siwiec ◽  
Paweł Narczyk ◽  
Adam Borkowski ◽  
...  
Keyword(s):  
Global Navigation Satellite System ◽  
Satellite System ◽  
High Accuracy ◽  
System On Chip ◽  
Navigation Satellite ◽  
Dual Frequency ◽  
Gnss Receiver ◽  
On Chip ◽  
Application Processor ◽  
Global Navigation Satellite

A dual-frequency all-in-one Global Navigation Satellite System (GNSS) receiver with a multi-core 32-bit RISC (reduced instruction set computing) application processor was integrated and manufactured as a System-on-Chip (SoC) in a 110 nm CMOS (complementary metal-oxide semiconductor) process. The GNSS RF (radio frequency) front-end with baseband navigation engine is able to receive, simultaneously, Galileo (European Global Satellite Navigation System) E1/E5ab, GPS (US Global Positioning System) L1/L1C/L5, BeiDou (Chinese Navigation Satellite System) B1/B2, GLONASS (GLObal NAvigation Satellite System of Russian Government) L1/L3/L5, QZSS (Quasi-Zenith Satellite System development by the Japanese government) L1/L5 and IRNSS (Indian Regional Navigation Satellite System) L5, as well as all SBAS (Satellite Based Augmentation System) signals. The ability of the GNSS to detect such a broad range of signals allows for high-accuracy positioning. The whole SoC (system-on-chip), which is connected to a small passive antenna, provides precise position, velocity and time or raw GNSS data for hybridization with the IMU (inertial measurement unit) without the need for an external application processor. Additionally, user application can be executed directly in the SoC. It works in the −40 to +105 °C temperature range with a 1.5 V supply. The assembled test-chip takes 100 pins in a QFN (quad-flat no-leads) package and needs only a quartz crystal for the on-chip reference clock driver and optional SAW (surface acoustic wave) filters. The radio performance for both wideband (52 MHz) channels centered at L1/E1 and L5/E5 is NF = 2.3 dB, G = 131 dB, with 121 dBc/Hz of phase noise @ 1 MHz offset from the carrier, consumes 35 mW and occupies a 4.5 mm2 silicon area. The SoC reported in the paper is the first ever dual-frequency single-chip GNSS receiver equipped with a multi-core application microcontroller integrated with embedded flash memory for the user application program.

Implementation of a Dual-Frequency GLONASS and GPS L1 C/A Software Receiver

2010 ◽  
Vol 63 (2) ◽  
pp. 269-287 ◽  
Author(s):  
S. Abbasian Nik ◽  
M. G. Petovello
Keyword(s):  
Global Navigation Satellite System ◽  
Critical Role ◽  
Satellite System ◽  
Navigation Satellite ◽  
Dual Frequency ◽  
Software Receiver ◽  
The Public ◽  
Global Navigation ◽  
Global Navigation Satellite

These days, Global Navigation Satellite System (GNSS) technology plays a critical role in positioning and navigation applications. Use of GNSS is becoming more of a need to the public. Therefore, much effort is needed to make the civilian part of the system more accurate, reliable and available, especially for the safety-of-life purposes. With the recent revitalization of Russian Global Navigation Satellite System (GLONASS), with a constellation of 20 satellites in August 2009 and the promise of 24 satellites by 2010, it is worthwhile concentrating on the GLONASS system as a method of GPS augmentation to achieve more reliable and accurate navigation solutions.

Performance Evaluation of the CNAV Broadcast Ephemeris

2019 ◽  
Vol 72 (5) ◽  
pp. 1331-1344
Author(s):  
Ahao Wang ◽  
Junping Chen ◽  
Yize Zhang ◽  
Jiexian Wang ◽  
Bin Wang
Keyword(s):  
Global Navigation Satellite System ◽  
Single Point ◽  
Satellite Orbit ◽  
Satellite System ◽  
Single Frequency ◽  
Navigation Satellite ◽  
Dual Frequency ◽  
Navigation Message ◽  
Global Navigation ◽  
Global Navigation Satellite

The new Global Positioning System (GPS) Civil Navigation Message (CNAV) has been transmitted by Block IIR-M and Block IIF satellites since April 2014, both on the L2C and L5 signals. Compared to the Legacy Navigation Message (LNAV), the CNAV message provides six additional parameters (two orbit parameters and four Inter-Signal Correction (ISC) parameters) for prospective civil users. Using the precise products of the International Global Navigation Satellite System Service (IGS), we evaluate the precision of satellite orbit, clock and ISCs of the CNAV. Additionally, the contribution of the six new parameters to GPS Single Point Positioning (SPP) is analysed using data from 22 selected Multi-Global Navigation Satellite System Experiment (MGEX) stations from a 30-day period. The results indicate that the CNAV/LNAV Signal-In-Space Range Error (SISRE) and orbit-only SISRE from January 2016 to March 2018 is of 0·5 m and 0·3 m respectively, which is improved in comparison with the results from an earlier period. The ISC precision of L1 Coarse/Acquisition (C/A) is better than 0·1 ns, and those of L2C and L5Q5 are about 0·4 ns. Remarkably, ISC correction has little effect on the single-frequency SPP for GPS users using civil signals (for example, L1C, L2C), whereas dual-frequency SPP with the consideration of ISCs results have an accuracy improvement of 18·6%, which is comparable with positioning accuracy based on an ionosphere-free combination of the L1P (Y) and L2P (Y) signals.

scholarly journals Background and Recent Advances in the Locata Terrestrial Positioning and Timing Technology

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1821 ◽  
Author(s):  
Chris Rizos ◽  
Ling Yang
Keyword(s):  
Literature Review ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
High Accuracy ◽  
Urban Environments ◽  
Navigation Satellite ◽  
Positioning Systems ◽  
Comprehensive Literature Review ◽  
The World ◽  
Global Navigation Satellite

Global Navigation Satellite System (GNSS) is the most widely used Positioning, Navigation, and Timing (PNT) technology in the world today, but it suffers some major constraints. Locata is a terrestrial PNT technology that can be considered as a type of localised “constellation”, which is able to provide high-accuracy PNT coverage where GNSS cannot be used. This paper presents a comprehensive literature review of the Locata technology and its applications. It seeks to answer questions, such as: (1) What is Locata and how does it work? (2) What makes Locata unique compared with other terrestrial positioning systems? (3) How has Locata been used in different applications for accurate PNT? (4) What are the current challenging issues that may restrict its further adoption for custom-grade navigation in urban environments?

scholarly journals Assessment of Dual Frequency GNSS Observations from a Xiaomi Mi 8 Android Smartphone and Positioning Performance Analysis

Electronics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 91 ◽  
Author(s):  
Umberto Robustelli ◽  
Valerio Baiocchi ◽  
Giovanni Pugliano
Keyword(s):  
Root Mean Square Error ◽  
Mean Square Error ◽  
Global Navigation Satellite System ◽  
Carrier Phase ◽  
Single Point ◽  
Satellite System ◽  
Navigation Satellite ◽  
Mean Square ◽  
Dual Frequency ◽  
Global Navigation Satellite

On May 2018 the world’s first dual-frequency Global Navigation Satellite System (GNSS) smartphone produced by Xiaomi equipped with a Broadcom BCM47755 chip was launched. It is able to receive L1/E1/ and L5/E5 signals from GPS, Galileo, Beidou, and GLONASS (GLObal NAvigation Satellite System) satellites. The main aim of this work is to achieve the phone’s position by using multi-constellation, dual frequency pseudorange and carrier phase raw data collected from the smartphone. Furthermore, the availability of dual frequency raw data allows to assess the multipath performance of the device. The smartphone’s performance is compared with that of a geodetic receiver. The experiments were conducted in two different scenarios to test the smartphone under different multipath conditions. Smartphone measurements showed a lower C/N0 and higher multipath compared with those of the geodetic receiver. This produced negative effects on single-point positioning as showed by high root mean square error (RMS). The best positioning accuracy for single point was obtained with the E5 measurements with a DRMS (horizontal root mean square error) of 4.57 m. For E1/L1 frequency, the 2DRMS was 5.36 m. However, the Xiaomi Mi 8, thanks to the absence of the duty cycle, provided carrier phase measurements used for a static single frequency relative positioning with an achieved 2DRMS of 1.02 and 1.95 m in low and high multipath sites, respectively.

Detection of Intermediate Spoofing Attack on Global Navigation Satellite System Receiver Through Slope Based Metrics

2020 ◽  
Vol 73 (5) ◽  
pp. 1052-1068
Author(s):  
Abdul Malik Khan ◽  
Naveed Iqbal ◽  
Adnan Ahmed Khan ◽  
Muhammad Faisal Khan ◽  
Attiq Ahmad
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
High Stakes ◽  
Gnss Receiver ◽  
Spoofing Detection ◽  
Global Navigation ◽  
Global Navigation Satellite

A spoofing attack on a global navigation satellite system (GNSS) receiver is a threat to a significant community of GNSS users due to the high stakes involved. This paper investigates the use of slope based metrics for the detection of spoofing. The formulation of slope based metrics involves monitoring correlators along with tracking correlators in the receiver's channel, which are slaved to the prompt tracking correlator. In this study, using some candidate metrics, detectors have been formed through the analysis of simulated spoofing attacks. A theoretical variance of each metric has also been calculated as a reference for the threshold. A threshold is estimated using the measured variance from the clean signals, for specific false alarm rate. By using the measured threshold, detectors are formed based on slope metrics. These detectors have been tested using TEXBAT data. The results show that the differential slope metrics have good performance. The results have also been compared with some other techniques of spoofing detection.

scholarly journals Accelerating a Cloud-Based Software GNSS Receiver

2014 ◽  
Vol 6 (3) ◽  
pp. 17-33
Author(s):  
Kamran Karimi ◽  
Aleks G. Pamir ◽  
M. Haris Afzal
Keyword(s):  
Global Navigation Satellite System ◽  
Satellite System ◽  
System Throughput ◽  
Total System ◽  
Navigation Satellite ◽  
Cloud Environment ◽  
Gnss Receiver ◽  
Multiple Copies ◽  
Client Request ◽  
Global Navigation Satellite

This paper discusses ways to reduce the execution time of a software Global Navigation Satellite System (GNSS) receiver that is meant for offline operation in a cloud environment. Client devices register satellite signals they receive, and send them to the cloud, to be processed by this software. The goal of this project is for each client request to be processed as fast as possible, but also to increase total system throughput by making sure as many requests as possible are processed within a unit of time. The characteristics of the application provided both opportunities and challenges for increasing performance. This paper describes the speedups we obtained by enabling the software to exploit multi-core CPUs and GPGPUs. It mentions which techniques worked and which did not. To increase throughput, it describes how to control the resources allocated for each invocation of the software to process a client request, such that multiple copies of the application can run at the same time. It uses the notion of the effective running time to measure the system's throughput when running multiple instances at the same time, and show how to determine when the system's computing resources have been saturated.

scholarly journals Performance Evaluation of Troposphere Estimated from Galileo-Only Multi-Frequency Observations

2020 ◽  
Vol 12 (3) ◽  
pp. 373 ◽  
Author(s):  
Lewen Zhao ◽  
Pavel Václavovic ◽  
Jan Douša
Keyword(s):  
Water Vapor ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Parameter Estimates ◽  
Navigation Satellite ◽  
Observation Model ◽  
Dual Frequency ◽  
Gps Satellites ◽  
Global Navigation ◽  
Global Navigation Satellite

The tropospheric delays estimated from the Global Navigation Satellite System (GNSS) have been proven to be an efficient product for monitoring variations of water vapor, which plays an important role in meteorology applications. The operational GNSS water vapor monitoring system is currently based on the Global Positioning System (GPS) and GLObal NAvigation Satellite System(GLONASS) dual-frequency observations. The Galileo satellite navigation system has been evolving continuously, and on 11 February 2019, the constellation reached 22 active satellites, achieving a capability of standalone Precise Point Positioning (PPP) and tropospheric estimation that is global in scope. This enhancement shows a 37% improvement if the precision of the Galileo-only zenith tropospheric delay, while we may anticipate further benefits in terms of tropospheric gradients and slant delays in the future if an optimal multi-constellation and multi-frequency processing strategy is used. First, we analyze the performance of the multi-frequency troposphere estimates based on the PPP raw observation model by comparing it with the standard ionosphere-free model. The performance of the Galileo-only tropospheric solution is then validated with respect to GPS-only solution using 48 globally distributed Multi-GNSS Experiment (MGEX) stations. The averaged bias and standard deviations are −0.3 and 5.8 mm when only using GPS satellites, respectively, and 0.0 and 6.2 mm for Galileo, respectively, when compared to the International GNSS Service (IGS) final Zenith Troposphere Delay(ZTD) products. Using receiver antenna phase center corrections from the corresponding GPS dual-frequency observations does not affect the Galileo PPP ambiguity float troposphere solutions. These results demonstrate a comparable precision achieved for both Galileo-only and GPS-only ZTD solutions, however, horizontal tropospheric gradients, estimated from standalone GPS and Galileo solutions, still show larger discrepancies, mainly due to their being less Galileo satellites than GPS satellites. Including Galileo E1, E5a, E5b, and E5 signals, along with their proper observation weighting, show the benefit of multi-frequency observations, further improving the ZTD precision by 4% when compared to the dual-frequency raw observation model. Overall, the presented results demonstrate good prospects for the application of multi-frequency Galileo observations for the tropospheric parameter estimates.

scholarly journals Assessment of the Steering Precision of a Hydrographic Unmanned Surface Vessel (USV) along Sounding Profiles Using a Low-Cost Multi-Global Navigation Satellite System (GNSS) Receiver Supported Autopilot

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3939 ◽  
Author(s):  
Mariusz Specht ◽  
Cezary Specht ◽  
Henryk Lasota ◽  
Piotr Cywiński
Keyword(s):  
Global Navigation Satellite System ◽  
Low Cost ◽  
Satellite System ◽  
Navigation Satellite ◽  
Promising Alternative ◽  
Gnss Receiver ◽  
Automatic Mode ◽  
Control Precision ◽  
Global Navigation ◽  
Global Navigation Satellite

The performance of bathymetric measurements by traditional methods (using manned vessels) in ultra-shallow waters, i.e., lakes, rivers, and sea beaches with a depth of less than 1 m, is often difficult or, in many cases, impossible due to problems related to safe vessel maneuvering. For this reason, the use of shallow draft hydrographic Unmanned Surface Vessels (USV) appears to provide a promising alternative method for performing such bathymetric measurements. This article describes the modernisation of a USV to switch from manual to automatic mode, and presents a preliminary study aimed at assessing the suitability of a popular autopilot commonly used in Unmanned Aerial Vehicles (UAV), and a low-cost multi-Global Navigation Satellite System (GNSS) receiver cooperating with it, for performing bathymetric measurements in automated mode, which involves independent movement along a specified route (hydrographic sounding profiles). The cross track error (XTE) variable, i.e., the distance determined between a USV’s position and the sounding profile, measured transversely to the course, was adopted as the measure of automatic control precision. Moreover, the XTE value was statistically assessed in the publication.

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