CORS ARCHITECTURE AND EVALUATION OF POSITIONING BY LOW-COST GNSS RECEIVER

In recent years, the use of low cost GNSS receivers is becoming widespread due to their increasing performance in the spatial positioning, flexibility, ease of use and really interesting price. In addition, a recent technique of Global Navigation Satellite System (GNSS) survey, called Network Real Time Kinematic (NRTK), allows to obtain to rapid and accurate positioning measurements. The main feature of this approach is to use the raw measurements obtained and stored from a network of Continuously Operating Reference Stations (CORS) in order to generate more reliable error models that can mitigate the distance-dependent errors within the area covered by the CORS. Also, considering the huge potential of this GNSS positioning system, the purpose of this paper is to analyze and investigate the performance of the NTRK approach using a low cost GNSS receiver, in stop-and-go kinematic technique. By several case studies it was shown that, using a low cost RTK board for Arduino environment, a smartphone with open source application for Android and the availability of data correction from CORS service, a quick and accurate positioning can be obtained. Because the measures obtained in this way are quite noisy and, more in general, increasing with the baseline, by a simple and suitable statistic treatment, it was possible to increase the quality of the measure. In this way, this low cost architecture could be applied in many geomatics fields. In addition to presenting the main aspects of the NTRK infrastructure and a review of several types of correction, a general workflow in order to obtain quality data in NRTK mode, regardless of the type of GNSS receiver (multi constellations, single or many frequencies, etc.) is discussed.

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A Testbed for GNSS-Based Positioning and Navigation Technologies in Smart Cities: The HANSEL Project

Smart Cities ◽

10.3390/smartcities3040060 ◽

2020 ◽

Vol 3 (4) ◽

pp. 1219-1241

Author(s):

Alex Minetto ◽

Fabio Dovis ◽

Andrea Vesco ◽

Miquel Garcia-Fernandez ◽

Àlex López-Cruces ◽

...

Keyword(s):

Smart Cities ◽

Low Cost ◽

Satellite System ◽

Cooperative Positioning ◽

Snapshot Positioning ◽

Gnss Receivers ◽

Urban Contexts ◽

Global Navigation Satellite ◽

Network Technologies

In urban contexts, the increasing density of electronic devices equipped with Global Navigation Satellite System (GNSS) receivers and complementary positioning technologies is attracting research and development efforts devoted to an improvement of the quality of life towards the smart city paradigm. Vehicular and pedestrian positioning and navigation capabilities are among the major drivers for innovation in this process. Ultra-low-cost electronics such as smartphones and Internet of Things (IoT) sensors aim at providing accurate and reliable positioning solutions through a set of promising solutions. Among these, snapshot positioning allows to remotely perform the post-processing of GNSS signals in IoT sensor networks while Wi-Fi™ ranging and cooperative positioning provide auxiliary anchors of opportunity to enhance indoor/outdoor positioning capabilities. This paper presents an innovative platform to perform a centralised testing and assessment of such positioning and navigation technologies along with a set of results obtained in the context of the European project HANSEL, by relying on current network technologies and infrastructures (i.e., Wi-Fi™ and cellular connectivity).

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Testing Multi-Frequency Low-Cost GNSS Receivers for Geodetic Monitoring Purposes

Sensors ◽

10.3390/s20164375 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4375

Author(s):

Veton Hamza ◽

Bojan Stopar ◽

Tomaž Ambrožič ◽

Goran Turk ◽

Oskar Sterle

Keyword(s):

Low Cost ◽

Base Point ◽

Satellite System ◽

Gnss Receivers ◽

The Difference ◽

Short Baselines ◽

Height Component ◽

Global Navigation Satellite ◽

High Level ◽

Positional Precision

Global Navigation Satellite System (GNSS) technology is widely used for geodetic monitoring purposes. However, in cases where a higher risk of receiver damage is expected, geodetic GNSS receivers may be considered too expensive to be used. As an alternative, low-cost GNSS receivers that are cheap, light, and prove to be of adequate quality over short baselines, are considered. The main goal of this research is to evaluate the positional precision of a multi-frequency low-cost instrument, namely, ZED-F9P with u-blox ANN-MB-00 antenna, and to investigate its potential for displacement detection. We determined the positional precision within static survey, and the displacement detection within dynamic survey. In both cases, two baselines were set, with the same rover point equipped with a low-cost GNSS instrument. The base point of the first baseline was observed with a geodetic GNSS instrument, whereas the second baseline was observed with a low-cost GNSS instrument. The results from static survey for both baselines showed comparable results for horizontal components; the precision was on a level of 2 mm or better. For the height component, the results show a better performance of low-cost instruments. This may be a consequence of unknown antenna calibration parameters for low-cost GNSS antenna, while statistically significant coordinates of rover points were obtained from both baselines. The difference was again more significant in the height component. For the displacement detection, a device was used that imposes controlled movements with sub-millimeter accuracy. Results, obtained on a basis of 30-min sessions, show that low-cost GNSS instruments can detect displacements from 10 mm upwards with a high level of reliability. On the other hand, low-cost instruments performed slightly worse as far as accuracy is concerned.

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Correlation between Ionospheric TEC and the DCB Stability of GNSS Receivers from 2014 to 2016

Remote Sensing ◽

10.3390/rs11222657 ◽

2019 ◽

Vol 11 (22) ◽

pp. 2657 ◽

Cited By ~ 4

Author(s):

Choi ◽

Sohn ◽

Lee

Keyword(s):

Estimation Method ◽

Satellite System ◽

Electron Content ◽

Strong Positive Correlation ◽

Low Latitude ◽

Total Electron ◽

Gnss Receiver ◽

Gnss Receivers ◽

Global Navigation Satellite ◽

The Relationship

The Global Navigation Satellite System (GNSS) differential code biases (DCBs) are a major obstacle in estimating the ionospheric total electron content (TEC). The DCBs of the GNSS receiver (rDCBs) are affected by various factors such as data quality, estimation method, receiver type, hardware temperature, and antenna characteristics. This study investigates the relationship between TEC and rDCB, and TEC and rDCB stability during a three-year period from 2014 to 2016. Linear correlations between pairs of variables, measured with Pearson’s coefficient (), are considered. It is shown that the correlation between TEC and rDCB is the smallest in low-latitude regions. The mid-latitude regions exhibit the maximum value of. In contrast, the correlation between TEC and rDCB root mean square (RMS, stability) was greater in low-latitude regions. A strong positive correlation (R≥0.90) on average between TEC and rDCB RMS was also revealed at two additional GNSS stations in low-latitude regions, where the correlation shows clear latitudinal dependency. We found that the correlation between TEC and rDCB stability is still very strong even after replacing a GNSS receiver.

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Performance Analysis of Network-RTK Techniques for Drone Navigation considering Ionospheric Conditions

Journal of Sensors ◽

10.1155/2018/5154697 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Tae-Suk Bae ◽

Minho Kim

Keyword(s):

Autonomous Navigation ◽

Low Cost ◽

Satellite System ◽

Test Results ◽

Static Mode ◽

Fixed Integer ◽

Gnss Receivers ◽

Global Navigation Satellite ◽

Ionospheric Condition ◽

Mapping Purpose

Recently, an accurate positioning has become the kernel of autonomous navigation with the rapid growth of drones including mapping purpose. The Network-based Real-time Kinematic (NRTK) system was predominantly used for precision positioning in many fields such as surveying and agriculture, mostly in static mode or low-speed operation. The NRTK positioning, in general, shows much better performance with the fixed integer ambiguities. However, the success rate of the ambiguity resolution is highly dependent on the ionospheric condition and the surrounding environment of Global Navigation Satellite System (GNSS) positioning, which particularly corresponds to the low-cost GNSS receivers. We analyzed the effects of the ionospheric conditions on the GNSS NRTK, as well as the possibility of applying the mobile NRTK to drone navigation for mapping. Two NRTK systems in operation were analyzed during a period of high ionospheric conditions, and the accuracy and the performance were compared for several operational cases. The test results show that a submeter accuracy is available even with float ambiguity under a favorable condition (i.e., visibility of the satellites as well as stable ionosphere). We still need to consider how to deal with ionospheric disturbances which may prevent NRTK positioning.

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Evaluation of Low-Cost GNSS Receiver under Demanding Conditions in RTK Network Mode

Sensors ◽

10.3390/s21165552 ◽

2021 ◽

Vol 21 (16) ◽

pp. 5552

Author(s):

Daniel Janos ◽

Przemysław Kuras

Keyword(s):

High Precision ◽

Patch Antenna ◽

Low Cost ◽

Satellite System ◽

Dual Frequency ◽

Satellite Systems ◽

Satellite Positioning ◽

Satellite Signal ◽

Global Navigation Satellite

Positioning with low-cost GNSS (Global Navigation Satellite System) receivers is becoming increasingly popular in many engineering applications. In particular, dual-frequency receivers, which receive signals of all available satellite systems, offer great possibilities. The main objective of this research was to evaluate the accuracy of a position determination using low-cost receivers in different terrain conditions. The u-blox ZED-F9P receiver was used for testing, with the satellite signal supplied by both a dedicated u-blox ANN-MB-00 low-cost patch antenna and the Leica AS10 high-precision geodetic one. A professional Leica GS18T geodetic receiver was used to acquire reference satellite data. In addition, on the prepared test base, observations were made using the Leica MS50 precise total station, which provided higher accuracy and stability of measurement than satellite positioning. As a result, it was concluded that the ZED-F9P receiver equipped with a patch antenna is only suitable for precision measurements in conditions with high availability of open sky. However, the configuration of this receiver with a geodetic-grade antenna significantly improves the quality of results, beating even professional geodetic equipment. In most cases of the partially obscured horizon, a high precision positioning was obtained, making the ZED-F9P a valuable alternative to the high-end geodetic receivers in many applications.

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Comparison of TEC Calculations Based on Trimble, Javad, Leica, and Septentrio GNSS Receiver Data

Remote Sensing ◽

10.3390/rs12193268 ◽

2020 ◽

Vol 12 (19) ◽

pp. 3268

Author(s):

Vladislav Demyanov ◽

Maria Sergeeva ◽

Mark Fedorov ◽

Tatiana Ishina ◽

Victor Jose Gatica-Acevedo ◽

...

Keyword(s):

Carrier Phase ◽

Satellite System ◽

Type Model ◽

Electron Content ◽

Noise Component ◽

Total Electron ◽

Gnss Receiver ◽

Tracking Technique ◽

Gnss Receivers ◽

Global Navigation Satellite

A Global Navigation Satellite System (GNSS) receiver is, to some extent, a “black box” when its data is used for ionospheric studies. Our results based on Javad, Septentrio, Trimble, and Leica GNSS receivers have proven that the accuracy of the slant Total Electron Content (TEC) calculation can differ significantly depending on the GNSS receiver type/model, because TEC measurements depend on the carrier phase tracking technique applied in a receiver. The correlation coefficient between carrier phase noise in L1 and L2 channels is considered as a possible indicator that shows if the L1-aided tracking technique or independent tracking is applied inside a receiver. An empirical model of the TEC noise component was provided to determine the TEC noise value in different types/models of GNSS receivers.

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Research and Development of Real-time High-precision GNSS Receivers: A Feasible Application for Surveying and Mapping in Vietnam

Inżynieria Mineralna ◽

10.29227/im-2021-02-36 ◽

2021 ◽

Vol 1 (2) ◽

Author(s):

Cong Khai PHAM ◽

Gia Trong NGUYEN ◽

Van Hai NGUYEN ◽

Trong Xuan TRAN

Keyword(s):

Real Time ◽

Low Cost ◽

Satellite System ◽

Dual Frequency ◽

Standard Format ◽

Gnss Receiver ◽

Programming Tool ◽

Standard Design ◽

Gnss Receivers ◽

Surveying And Mapping

In recent years, the Global Navigation Satellite System (GNSS) has been widely applied insurveying and mapping. Currently, in Vietnam, dual-frequency GNSS receivers are quite extensivelyapplied with the real-time kinematic (RTK) measurement technique using a continuously operatingreference station network. However, high-accuracy GNSS receivers are often expensive, sometimes notmeeting the needs of users for specific applications. This research develops two types of low-cost highprecisionGNSS receivers for RTK positioning for different purposes. First, the millimeter precisionGNSS receiver used in real-time displacement monitoring is based on Trimble's BD970 mainboardtechnology and some other modules. These components are interconnected according to a standarddesign scheme and assembled in an enclosure to form a GNSS receiver. In addition, a GNSS datatransmission in the National Marine Electronics Association standard format by Networked Transport ofRadio Technical Commission for Maritime Services via Internet Protocol (NTRIP) has beendesigned and developed. The GNSS receiver after development is loaded with program code written inthe C# programming language, using the Arduino programming tool. Second, the GNSS receivers havethe centimeter accuracy for RTK positioning used in surveying and mapping based on U-blox'smainboard technology and some other modules. These modules are also connected together according toa standard design scheme and assembled in an enclosure to form a complete GNSS receiver. Theevaluation results show that the designed and developed GNSS receivers completely meet therequirements of surveying and mapping in coal mines in Vietnam, such as real-time monitoring oflandslides, surveying and topographical mapping and other surveying works to serve the mining process.

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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 ◽

10.3390/s19183939 ◽

2019 ◽

Vol 19 (18) ◽

pp. 3939 ◽

Cited By ~ 16

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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Operation of geodetic GNSS instruments under chirp signal L1 jamming

Geodetski vestnik ◽

10.15292/geodetski-vestnik.2021.02.189-204 ◽

2021 ◽

Vol 65 (02) ◽

pp. 189-204

Author(s):

Franc Dimc ◽

Polona Pavlovčič Prešeren ◽

Matej Bažec

Keyword(s):

Global Positioning System ◽

Signal To Noise Ratio ◽

Satellite System ◽

Signal Interference ◽

Short Term ◽

Global Positioning ◽

Gnss Receivers ◽

Global Navigation Satellite ◽

To Receive

This paper presents the results of a vulnerability test of several geodetic Global Navigation Satellite System (GNSS) receivers in case of intentional signal interference in the frequency L1 for GPS (Global Positioning System). Nine instruments from different manufacturers (i.e., Leica Geosystems AG, Trimble Inc., Javad GNSS) were tested. The test was based on static and kinematic jamming. A static scenario with three-minute interruptions was followed by experiments with a stationary jammer located at distances from 10 m to 160 m from the receivers. For short-term kinematic interference, the jammer was installed in the vehicle, which passed the GNSS instruments at different speeds. An analysis of different scenarios showed that the jammer interrupted GPS but not GLONASS signals in certain situations. Since Galileo was not nominally operational at the time of the July 2019 measurements, only GPS and GLONASS were eligible for the study. The geodetic GNSS instruments reacted to the interruptions with a decreased signal-to-noise-ratio (SNR) and either with a complete inability to determine the code/phase position or with an incorrect calculation of phase ambiguities (initialization), which also affected the quality of the positioning. The proximity of the jammer played the most significant role in the complete inability to receive the signal; however, for the incorrect positioning longer duration of jamming was also a reason.

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Evaluating the Vulnerability of Several Geodetic GNSS Receivers under Chirp Signal L1/E1 Jamming

Sensors ◽

10.3390/s20030814 ◽

2020 ◽

Vol 20 (3) ◽

pp. 814 ◽

Cited By ~ 2

Author(s):

Matej Bažec ◽

Franc Dimc ◽

Polona Pavlovčič-Prešeren

Keyword(s):

Carrier Phase ◽

Low Cost ◽

Satellite System ◽

Navigation Satellite ◽

Chirp Signal ◽

Testing Area ◽

Practical Solution ◽

Gnss Receivers ◽

Global Navigation Satellite ◽

Suitable Area

Understanding the factors that might intentionally influence the reception of global navigation satellite system (GNSS) signals can be a challenging topic today. The focus of this research is to evaluate the vulnerability of geodetic GNSS receivers under the use of a low-cost L1/E1 frequency jammer. A suitable area for testing was established in Slovenia. Nine receivers from different manufacturers were under consideration in this study. While positioning, intentional 3-minute jammings were performed by a jammer that was located statically at different distances from receivers. Furthermore, kinematic disturbances were performed using a jammer placed in a vehicle that passed the testing area at various speeds. An analysis of different scenarios indicated that despite the use of an L1/E1 jammer, the GLONASS (Russian: Globalnaya Navigatsionnaya Sputnikovaya Sistema) and Galileo signals were also affected, either due to the increased carrier-to-noise-ratio (C/N0) or, in the worst cases, by a loss-of-signal. A jammer could substantially affect the position, either with a lack of any practical solution or even with a wrong position. Maximal errors in the carrier-phase positions, which should be considered a concern for geodesy, differed by a few metres from the exact solution. The factor that completely disabled the signal reception was the proximity of a jammer, regardless of its static or kinematic mode.

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