scholarly journals Feasibility of Consumer Grade GNSS Receivers for the Integration in Multi-Sensor-Systems

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2463 ◽  
Author(s):  
Tobias Kersten ◽  
Jens-André Paffenholz
Keyword(s):  
System Integration ◽  
Carrier Phase ◽  
Low Cost ◽  
Power Saving ◽  
Low Noise ◽  
Small Scale ◽  
Sensor Systems ◽  
Phase Code ◽  
Gnss Receivers ◽  
Zero Baseline

Various GNSS applications require low-cost, small-scale, lightweight and power-saving GNSS devices and require high precision in terms of low noise for carrier phase and code observations. Applications vary from navigation approaches to positioning in geo-monitoring units up to integration in multi-sensor-systems. For highest precision, only GNSS receivers are suitable that provide access to raw data such as carrier phase, code ranges, Doppler and signal strength. A system integration is only possible if the overall noise level is known and quantified at the level of the original observations. A benchmark analysis based on a zero baseline is proposed to quantify the stochastic properties. The performance of the consumer grade GNSS receiver is determined and evaluated against geodetic GNSS receivers to better understand the utilization of consumer grade receivers. Results indicate high similarity to the geodetic receiver, even though technical limitations are present. Various stochastic techniques report normally distributed carrier-phase noise of 2 mm and code-range noise of 0.5–0.8 m. This is confirmed by studying the modified Allan standard deviation and code-minus-carrier combinations. Derived parameters serve as important indicators for the integration of GNSS receivers into multi-sensor-systems.

NanoMagSat, a 16U nanosatellite constellation high-precision magnetic project to initiate permanent low-cost monitoring of the Earth’s magnetic field and ionospheric environment

2021 ◽  
Author(s):  
Gauthier Hulot ◽  
Jean-Michel Léger ◽  
Lasse B. N. Clausen ◽  
Florian Deconinck ◽  
Pierdavide Coïsson ◽  
...  
Keyword(s):  
High Precision ◽  
Geomagnetic Field ◽  
Low Cost ◽  
Low Noise ◽  
Low Earth Orbit ◽  
Dual Frequency ◽  
Observatory Data ◽  
Vector Magnetometer ◽  
Gnss Receivers ◽  
Global Coverage

<p>The geomagnetic field has been continuously monitored from low-Earth orbit (LEO) since 1999, complementing ground-based observatory data by providing calibrated scalar and vector measurements with global coverage. The successful three-satellite ESA Swarm constellation is expected to remain in operation up to at least 2025. Further monitoring the field from space with high-precision absolute magnetometry beyond that date is of critical importance for improving our understanding of dynamics of the multiple components of this field, as well as that of the ionospheric environment. Here, we will report on the latest status of the NanoMagSat project, which aims to deploy and operate a new constellation concept of three identical 16U nanosatellites, using two inclined (approximately 60°) and one polar LEO, as well as an innovative payload including an advanced Miniaturized Absolute scalar and self-calibrated vector Magnetometer (MAM) combined with a set of precise star trackers (STR), a compact High-frequency Field Magnetometer (HFM, sharing subsystems with the MAM), a multi-needle Langmuir Probe (m-NLP) and dual frequency GNSS receivers. The data to be produced will at least include 1 Hz absolutely calibrated and oriented magnetic vector field (using the MAM and STR), 2 kHz very low noise magnetic scalar (using the MAM) and vector (using the HFM) field, 2 kHz local electron density (using the m-NLP) as well as precise timing, location and TEC products. In addition to briefly presenting the nanosatellite and constellation concepts, as well as the evolving programmatic status of the mission (which already underwent a consolidation study funded by the ESA Scout programme), this presentation will illustrate through a number of E2E simulations the ability of NanoMagSat to complement and improve on many of the science goals of the Swarm mission at a much lower cost, and to bring innovative science capabilities for ionospheric investigations. NanoMagSat could form the basis of a permanent collaborative constellation of nanosatellites for low-cost long-term monitoring of the geomagnetic field and ionospheric environment from space.</p>

scholarly journals Potential of Cost-Efficient Single Frequency GNSS Receivers for Water Vapor Monitoring

2018 ◽  
Vol 10 (9) ◽  
pp. 1493 ◽  
Author(s):  
Andreas Krietemeyer ◽  
Marie-claire ten Veldhuis ◽  
Hans van der Marel ◽  
Eugenio Realini ◽  
Nick van de Giesen
Keyword(s):  
Water Vapor ◽  
Low Cost ◽  
Global Navigation Satellite Systems ◽  
Single Frequency ◽  
Small Scale ◽  
Reference Network ◽  
Tropospheric Delay ◽  
Dual Frequency ◽  
Gnss Receivers ◽  
Cost Efficient

Dual-frequency Global Navigation Satellite Systems (GNSSs) enable the estimation of Zenith Tropospheric Delay (ZTD) which can be converted to Precipitable Water Vapor (PWV). The density of existing GNSS monitoring networks is insufficient to capture small-scale water vapor variations that are especially important for extreme weather forecasting. A densification with geodetic-grade dual-frequency receivers is not economically feasible. Cost-efficient single-frequency receivers offer a possible alternative. This paper studies the feasibility of using low-cost receivers to increase the density of GNSS networks for retrieval of PWV. We processed one year of GNSS data from an IGS station and two co-located single-frequency stations. Additionally, in another experiment, the Radio Frequency (RF) signal from a geodetic-grade dual-frequency antenna was split to a geodetic receiver and two low-cost receivers. To process the single-frequency observations in Precise Point Positioning (PPP) mode, we apply the Satellite-specific Epoch-differenced Ionospheric Delay (SEID) model using two different reference network configurations of 50–80 km and 200–300 km mean station distances, respectively. Our research setup can distinguish between the antenna, ionospheric interpolation, and software-related impacts on the quality of PWV retrievals. The study shows that single-frequency GNSS receivers can achieve a quality similar to that of geodetic receivers in terms of RMSE for ZTD estimations. We demonstrate that modeling of the ionosphere and the antenna type are the main sources influencing the ZTD precision.

Small Scale Skid-Mounted Natural Gas to Hydrogen Production System Provides Competitive Hydrogen for China

2021 ◽  
Author(s):  
Pengfei Song ◽  
Rui Wang ◽  
Yiyan Sui ◽  
Tongwen Shan ◽  
Jianguo Hou ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Natural Gas ◽  
System Integration ◽  
Life Cycle Cost ◽  
High Efficiency ◽  
Low Cost ◽  
Small Scale ◽  
Hydrogen Generator ◽  
Technical Parameters ◽  
Full Life Cycle

Abstract Because of its convenience, high efficiency and low cost, small-scale skid-mounted hydrogen generator has become a hydrogen-production object of intense research efforts worldwide and has broad prospects in application. We analyze the technical points and difficulties in detail of this kind of on-site compact hydrogen generators from natural gas, by each section in the production process. It is suitable for integrated hydrogen refueling stations due to easy transportation and installation. Related applications are introduced by comparing the technical parameters of recent typical products in the world. Meanwhile, we calculate that the full life cycle cost of hydrogen from skid-mounted hydrogen generator from natrual gas can achieve less than 40CNY / kgH2, which is more economic than other possible hydrogen sources and transportation modes of a hydrogen refueling station. Although the advantages mentioned above, we point out that technology innovation is still desirable, especially in the process of reforming, automatic control, system integration and catalysis, to realize the minimization of skid-mounted hydrogen generators base on natural gas, for its further and wider application in the future.

scholarly journals Testing the Performance of Multi-Frequency Low-Cost GNSS Receivers and Antennas

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2029
Author(s):  
Veton Hamza ◽  
Bojan Stopar ◽  
Oskar Sterle
Keyword(s):  
Low Cost ◽  
Geodetic Network ◽  
Satellite System ◽  
Low Noise ◽  
Short Baseline ◽  
True Value ◽  
Gnss Receivers ◽  
Baseline Test ◽  
The Difference ◽  
The Impact

Global Navigation Satellite System (GNSS) low-cost multi-frequency receivers are argued as an alternative to geodetic receivers for many applications. Calibrated low-cost antennas recently became available on the market making low-cost instruments more comparable with geodetic ones. The main goal of this research was to evaluate the noise of low-cost GNSS receivers, to compare the positioning quality from different types of low-cost antennas, and to analyze the positioning differences between low-cost and geodetic instruments. The results from a zero baseline test indicated that the u-blox multi-frequency receiver, namely, ZED-F9P, had low noise that was at the sub-millimeter level. To analyze the impact of the antennas in the obtained coordinates, a short baseline test was applied. Both tested uncalibrated antennas (Tallysman TW3882 and Survey) demonstrated satisfactory positioning performance. The Tallysman antenna was more accurate in the horizontal position determination, and the difference from the true value was only 0.1 mm; while, for the Survey antenna, the difference was 1.0 mm. For the ellipsoid height, the differences were 0.3 and 0.6 mm for the Survey and Tallysman antennas, respectively. The comparison of low-cost receivers with calibrated low-cost antennas (Survey Calibrated) and geodetic instruments proved better performance for the latter. The geodetic GNSS instruments were more accurate than the low-cost instruments, and the precision of the estimated coordinates from the geodetic network was also greater. Low-cost GNSS instruments were not at the same level as the geodetic ones; however, considering their cost, they demonstrated excellent performance that is sufficiently appropriate for various geodetic applications.

A Performance Analysis of Low-Cost GPS Receivers in Kinematic Applications

2009 ◽  
Vol 62 (4) ◽  
pp. 687-697 ◽  
Author(s):  
R. M. Alkan ◽  
M. H. Saka
Keyword(s):  
Carrier Phase ◽  
Low Cost ◽  
Single Frequency ◽  
Gps Receiver ◽  
Gps Receivers ◽  
Kinematic Positioning ◽  
Golden Horn ◽  
Differential Positioning ◽  
Marine Applications ◽  
Zero Baseline

Low-cost OEM GPS receivers with the capability of tracking the carrier phase are now used for many applications in the navigation and tracking arena. These receivers provide flexibility in applying carrier smoothing algorithms to improve the pseudorange positioning accuracy and even perform carrier-phase differential positioning. In this study, the performance of a low-cost single-frequency OEM GPS receiver for high-accuracy kinematic positioning in marine applications is investigated. As a first step, a set of zero baseline tests were carried out to evaluate the performance of the GPS receivers. In the second stage, a kinematic test was conducted at the Halic (Golden Horn), Istanbul. The results show that kinematic positioning with centimetre level accuracy can be achieved by the low-cost OEM GPS receiver in differential mode, suggesting its use in a variety of kinematic applications. The use of such a system could considerably reduce the cost of the GPS receiver and the total project costs of many applications.

scholarly journals Performance Analysis of Relative Positioning using GPS and BDS signals

2019 ◽  
Vol 94 ◽  
pp. 03005
Author(s):  
Jae Hee Noh ◽  
Sun Yong Lee ◽  
Deok Won Lim ◽  
Gwang Hee Jo ◽  
Jin Hyuk Lee ◽  
...  
Keyword(s):  
Carrier Phase ◽  
Low Cost ◽  
Integrated System ◽  
Tropospheric Delay ◽  
Relative Positioning ◽  
Positioning Accuracy ◽  
Phase Measurements ◽  
Gnss Receivers ◽  
Satellite Signal ◽  
Satellite Clock Error

In general, the satellite signal received by GNSS receivers has errors such as satellite clock error, orbit error, ionospheric delay and tropospheric delay. In environments where high positioning accuracy is required, these error factors can be eliminated by using relative positioning using code measurements with carrier phase measurements. If relative positioning is performed using carrier phase measurements, it is possible to have positioning accuracy of cm level. In this paper, we analyse the positioning accuracy of relative positioning using the L1 signal of GPS and BDS. For this study, we collect GPS and BDS signal using two low-cost receivers. We also designed a software-based platform to perform the relative positioning. Finally, we analyse relative positioning accuracy for GPS/BDS integrated system as well as relative positioning accuracy for GPS and BDS.

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

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 814 ◽  
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.

Transmission Electron Microscopy of oriented Co84Cr14Ta2 thin films for longitudinal magnetic recording

1991 ◽  
Vol 49 ◽  
pp. 756-757
Author(s):  
T. P. Nolan
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Cost ◽  
Low Noise ◽  
Information Storage ◽  
High Coercivity ◽  
Magnetic Alloy ◽  
Magnetic Media ◽  
Transmission Electron

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.

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