scholarly journals Digital Magnetic Compass Integration with Stationary, Land-Based Electro-Optical Multi-Sensor Surveillance System

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4331 ◽  
Author(s):  
Livada ◽  
Vujić ◽  
Radić ◽  
Unkašević ◽  
Banjac
Keyword(s):  
Long Range ◽  
Satellite System ◽  
Magnetic Compass ◽  
Surveillance Systems ◽  
Accuracy Measurement ◽  
Measurement Results ◽  
Compensation Technique ◽  
Compass Calibration ◽  
Global Navigation Satellite ◽  
Technical Solutions

Multi-sensor imaging systems using the global navigation satellite system (GNSS) and digital magnetic compass (DMC) for geo-referencing have an important role and wide application in long-range surveillance systems. To achieve the required system heading accuracy, the specific magnetic compass calibration and compensation procedures, which highly depend on the application conditions, should be applied. The DMC compensation technique suitable for the operation environment is described and different technical solutions are studied. The application of the swinging procedure was shown as a good solution for DMC compensation in a given application. The selected DMC was built into a system to be experimentally evaluated, both under laboratory and field conditions. The implementation of the compensation procedure and magnetic sensor integration in systems is described. The heading accuracy measurement results show that DMC could be successfully integrated and used in long-range surveillance systems providing required geo-referencing data.

scholarly journals Tropical Cyclone Center Fix Using CYGNSS Winds

2019 ◽  
Vol 58 (9) ◽  
pp. 1993-2003 ◽  
Author(s):  
David Mayers ◽  
Christopher Ruf
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Satellite System ◽  
Center Location ◽  
Residual Difference ◽  
Measurement Results ◽  
Storm Center ◽  
Global Navigation Satellite ◽  
Cross Track ◽  
Along Track

AbstractA new method is described for determining the center location of a tropical cyclone (TC) using wind speed measurements by the NASA Cyclone Global Navigation Satellite System (CYGNSS). CYGNSS measurements made during TC overpasses are used to constrain a parametric wind speed model in which storm center location is varied. The “MTrack” storm center location is selected to minimize the residual difference between model and measurement. Results of the MTrack center fix are compared to the National Hurricane Center (NHC) Best Track, the Automated Rotational Center Hurricane Eye Retrieval (ARCHER), and aircraft reconnaissance fixes for category 1–category 3 TCs during the 2017 and 2018 hurricane seasons. MTrack produces storm center locations at intermediate times between NHC fixes with a factor of 5.6 overall reduction in sensitivity to uncertainties in the NHC fixes between which it interpolates. The MTrack uncertainty is found to be larger in the cross-track direction than the along-track direction, although this behavior and the absolute accuracy of position estimates require further investigation.

scholarly journals Variability and Performance of Short to Long-Range Single Baseline RTK GNSS Positioning in Indonesia

2019 ◽  
Vol 94 ◽  
pp. 01012 ◽  
Author(s):  
Irwan Gumilar ◽  
Brian Bramanto ◽  
Fuad F. Rahman ◽  
I Made D. A. Hermawan
Keyword(s):  
Long Range ◽  
High Frequency ◽  
Carrier Phase ◽  
Satellite System ◽  
High Accuracy ◽  
Gnss Positioning ◽  
And Performance ◽  
Gnss Network ◽  
Single Baseline ◽  
Global Navigation Satellite

As the modernized Global Navigation Satellite System (GNSS) method, Real Time Kinematic (RTK) ensures high accuracy of position (within several centimeters). This method uses Ultra High Frequency (UHF) radio to transmit the correction data, however, due to gain and power issues, Networked Transport of RTCM via Internet Protocol (RTCM) is used to transmit the correction data for a longer baseline. This Research aims to investigate the performance of short to long-range single baseline RTK GNSS (Up to 80 KM) by applying modified LAMBDA method to resolve the ambiguity in carrier phase. The RTK solution then compared with the differential GNSS network solution. The results indicate that the differences are within RTK accuracy up to 80 km are several centimeter for horizontal solution and three times higher for vertical solution.

scholarly journals Assessment of the Steering Precision of a Hydrographic USV along Sounding Profiles Using a High-Precision GNSS RTK Receiver Supported Autopilot

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5637
Author(s):  
Łukasz Marchel ◽  
Cezary Specht ◽  
Mariusz Specht
Keyword(s):  
High Precision ◽  
Low Cost ◽  
Path Following ◽  
Satellite System ◽  
Magnetic Compass ◽  
Reference Station ◽  
Positioning System ◽  
Positioning Accuracy ◽  
Unmanned Surface Vehicles ◽  
Global Navigation Satellite

Unmanned Surface Vehicles (USV) are increasingly used to perform numerous tasks connected with measurements in inland waters and seas. One of such target applications is hydrography, where traditional (manned) bathymetric measurements are increasingly often realized by unmanned surface vehicles. This pertains especially to restricted or hardly navigable waters, in which execution of hydrographic surveys with the use of USVs requires precise maneuvering. Bathymetric measurements should be realized in a way that makes it possible to determine the waterbody’s depth as precisely as possible, and this requires high-precision in navigating along planned sounding profiles. This paper presents research that aimed to determine the accuracy of unmanned surface vehicle steering in autonomous mode (with a Proportional-Integral-Derivative (PID) controller) along planned hydrographic profiles. During the measurements, a high-precision Global Navigation Satellite System (GNSS) Real Time Kinematic (RTK) positioning system based on a GNSS reference station network (positioning accuracy: 1–2 cm, p = 0.95) and a magnetic compass with the stability of course maintenance of 1°–3° Root Mean Square (RMS) were used. For the purpose of evaluating the accuracy of the vessel’s path following along sounding profiles, the cross track error (XTE) measure, i.e., the distance between an USV’s position and the hydrographic profile, calculated transversely to the course, was proposed. The tests were compared with earlier measurements taken by other unmanned surface vehicles, which followed the exact same profiles with the use of much simpler and low-cost multi-GNSS receiver (positioning accuracy: 2–2.5 m or better, p = 0.50), supported with a Fluxgate magnetic compass with a high course measurement accuracy of 0.3° (p = 0.50 at 30 m/s). The research has shown that despite the considerable difference in the positioning accuracy of both devices and incomparably different costs of both solutions, the authors proved that the use of the GNSS RTK positioning system, as opposed to a multi-GNSS system supported with a Fluxgate magnetic compass, influences the precision of USV following sounding profiles to an insignificant extent.

scholarly journals MATHEMATICAL ANALYSIS OF THE ALGORITHMS USED IN MODERNIZED METHODS OF BUILDING MEASUREMENTS WITH RTN GNSS TECHNOLOGY

2015 ◽  
Vol 21 (4) ◽  
pp. 848-866 ◽  
Author(s):  
Robert Krzyżek
Keyword(s):  
Real Time ◽  
Mathematical Analysis ◽  
Classical Method ◽  
Satellite System ◽  
Building Structures ◽  
Base Points ◽  
Measurement Results ◽  
Innovative Solution ◽  
The Difference ◽  
Global Navigation Satellite

The use of RTN GNSS surveying technology (Real Time Kinematic Global Navigation Satellite System) for direct measurements of building structures is extremely difficult, and often impossible. Therefore, the real-time technology is supported by indirect methods of measurements. One such solution is the method of line-line intersection. Having determined the position (the coordinates) of the so-called base points on the extension of the wall faces of a building, and having calculated the coordinates of intersection of the lines of relationships between the base points, the coordinates of corners of a building structure are obtained, which are relatively unreliable. In order to increase the reliability of these coordinates, the author proposes to add an innovative solution called vector translation to the classical method of line-line intersection. This paper proves the thesis on the increased reliability of determining the coordinates of corners of buildings by conducting an appropriate mathematical analysis of these formulas, using the algorithm developed by the author. The performed analysis shows that this innovative solution results in a smaller difference between the adjusted coordinates relative to the theoretical ones, than the difference captured from the "raw" measurement results with respect to the theoretical values.

scholarly journals Rancang Bangun Alat Pendeteksi Kondisi Cuaca Kota Balikpapan Menggunakan Global Navigation Satellite System (GNSS) Wind Turbine

2019 ◽  
Vol 2 (2) ◽  
pp. 11-18
Author(s):  
Budiani Fitria Endrawati ◽  
Adhe Yusphie ◽  
Arum Prastiyo Putri ◽  
Azam Fadhil A ◽  
Mohammad Saiful R ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
East Kalimantan ◽  
Measurement Results ◽  
Global Navigation ◽  
Global Navigation Satellite ◽  
The City

Balikpapan is one of the cities in East Kalimantan with unique characteristic of the region. The characteristics of the region and the height of the area from the sea surface of the city of Balikpapan is one of the factors, therefore need to be designed a tool to detect weather especially in Balikpapan city. The device design using Global Navigation Satellite System (GNSS) Wind Turbine. The measurement results are based on temperature, humidity and wind speed. From the measurement of temperature, humidity and wind speed obtained an average of 30.97oC; 73.49% and 2.91 m/s. According to method World Meteorological Organization, temperature, humidity and wind speed data is accepted.

Improving GNSS Navigation and Control with Electronic Compass in Unmanned System

2019 ◽  
Vol 23 (3) ◽  
pp. 427-436
Author(s):  
Xi Han ◽  
Xiaolin Zhang ◽  
Yuansheng Liu ◽  
◽  
◽  
...  
Keyword(s):  
Neural Network ◽  
Learning Algorithm ◽  
Back Propagation ◽  
Satellite System ◽  
Back Propagation Neural Network ◽  
Angle Data ◽  
Compensation Technique ◽  
Unmanned System ◽  
Global Navigation Satellite ◽  
Electronic Compass

This paper proposes a compensation technique for the global navigation satellite system (GNSS)/real-time kinematic (RTK) course angle data using an electronic compass for an unmanned system. Additionally, the proportion, integral, and derivative control based on a back-propagation neural network (BP-PID) is introduced to improve the steering safety and riding comfort. The course angle jitter was determined. Because the GNSS/RTK receiver cannot offer stable heading data under specific conditions, including but not limited to susceptibility to obstacles, complex electromagnetic environment, and fewer satellites. The compensation algorithm is based on the determination of the GNSS course angle variance ratio and the asynchronous characteristic between the GNSS and an electronic compass. The combined data provide accurate and robust navigation information for an outdoor unmanned system. To address the limitation of the in-system parameter adjustment, a back-propagation (BP) neural network is adhibited to a conventional proportion, integral, and derivative (PID) lateral control system. The BP-PID control module updates the incremental PID parameters through self-learning, and results in the smoother operation of the vehicle. The flowchart of the learning algorithm and method of calculating the parameters are presented. A typical measurement was conducted and the obtained results were compared with typical RTK navigation results. Thus, the effectiveness of the proposed compensation method was confirmed.

scholarly journals A Novel Ancient Coin-Like Fractal Multiband Antenna for Wireless Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhen Yu ◽  
Jianguo Yu ◽  
Xiaoying Ran ◽  
Chenhua Zhu
Keyword(s):  
Satellite System ◽  
Structural Features ◽  
Microstrip Antennas ◽  
Fourth Generation ◽  
Navigation Satellite ◽  
Frequency Bands ◽  
Satellite Navigation System ◽  
Wireless Applications ◽  
Measurement Results ◽  
Global Navigation Satellite

This study proposes a novel square-circle structure fractal multibroadband planar antenna, similar to an ancient Chinese coin-like structure, for second generation (2G), third generation (3G), fourth generation (4G), WLAN, and navigation wireless applications. The device is based on the principles and structural features of conventional monopole antenna elements, combined with the advantages of microstrip antennas and fractal geometry. A fractal method was presented for circular nested square slotted structures, similar to an ancient Chinese copper coin. The proposed antenna adapted five iterations on a fractal structure radiator, which covers more than ten mobile applications in three broad frequency bands with a bandwidth of 70% (1.43–2.97 GHz) for DCS1800, TD-SCDMA, WCDMA, CDMA2000, LTE33-41, Bluetooth, GPS (Global Positioning System), BDS (BeiDou Navigation Satellite System), GLONSS (Global Navigation Satellite System), GALILEO (Galileo Satellite Navigation System), and WLAN frequency bands, 16.32% (3.32–3.91 GHz) for LTE42, LTE43, and WiMAX frequency bands, and 10.92% (4.85–5.41 GHz) for WLAN frequency band. The proposed antenna was fabricated on a 1.6 mm thick G10/FR4 substrate with a dielectric constant of 4.4 and a size of 88.5 × 60 mm2. The measurement results reveal that the omnidirectional radiation patterns achieve a gain of 1.16–3.75 dBi and an efficiency of 40–72%. The good agreement between the measurement results and simulation validates the proposed design approach and satisfies the requirements for various wireless applications.

scholarly journals On the Calibration of GNSS-Based Vehicle Speed Meters

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 591 ◽  
Author(s):  
Adolfo Martucci ◽  
Giovanni Cerasuolo ◽  
Orsola Petrella ◽  
Marco Laracca
Keyword(s):  
Calibration Method ◽  
Satellite System ◽  
Wide Field ◽  
Vehicle Speed ◽  
Experimental Calibration ◽  
International Laboratory Accreditation Cooperation ◽  
Technical Requirements ◽  
Measurement Results ◽  
On The Road ◽  
Global Navigation Satellite

Thanks to their metrological characteristics (accuracy, dimensions, synchronization capability, easy interfacing, and so on), in the last few years, the GNSS (Global Navigation Satellite System) based speed instruments are often used in a wide field of application. The traceability of the measurement results achieved by the GNSS instrument should be made by means of calibration procedures in compliance with the ISO/IEC 17025 standard and ILAC (International Laboratory Accreditation Cooperation) policy on the traceability of measurement results. In this context, some calibration methodologies have been proposed in the literature or used by some calibration centers. In a speed range from 1 to 300 km/h, an analysis on the suitability of the experimental calibration method (based on a couple of photocells placed on the road at a certain distance) for the GNSS speed measurement systems is presented in this paper. An analysis of the measurement setup has allowed for the recognition of both all the uncertainty contributions and defines the variability range of their values. After the formulation of the relationships between the uncertainty contributions and the total calibration uncertainty due to the calibration method, the sensitivity analysis has been made. The analyzed measurement setup, even if considering a careful choice of both instrumentations and methodologies, is suitable for the calibration of high accuracy GNSS based instruments only considering distances between the photocells sufficiently large and for speed values lower than 200 km/h. In any case, the proposed analysis can be a useful tool to allow for the choices on the measurement setup to reach the desired trade-off between calibration costs and compliance with technical requirements and also the calibration of instrumentation different by GNSS.

The characteristics of transforming coordinates from the geocentric system WGS-84 for the Mercator projection under low latitudes conditions

2018 ◽  
Vol 940 (10) ◽  
pp. 2-6
Author(s):  
J.A. Younes ◽  
M.G. Mustafin
Keyword(s):  
Coordinate System ◽  
Satellite System ◽  
Programming Algorithm ◽  
Low Latitude ◽  
Model Calculations ◽  
Mercator Projection ◽  
Low Latitudes ◽  
Rectangular Coordinates ◽  
Global Navigation Satellite ◽  
Coordination Methods

The issue of calculating the plane rectangular coordinates using the data obtained by the satellite observations during the creation of the geodetic networks is discussed in the article. The peculiarity of these works is in conversion of the coordinates into the Mercator projection, while the plane coordinate system on the base of Gauss-Kruger projection is used in Russia. When using the technology of global navigation satellite system, this task is relevant for any point (area) of the Earth due to a fundamentally different approach in determining the coordinates. The fact is that satellite determinations are much more precise than the ground coordination methods (triangulation and others). In addition, the conversion to the zonal coordinate system is associated with errors; the value at present can prove to be completely critical. The expediency of using the Mercator projection in the topographic and geodetic works production at low latitudes is shown numerically on the basis of model calculations. To convert the coordinates from the geocentric system with the Mercator projection, a programming algorithm which is widely used in Russia was chosen. For its application under low-latitude conditions, the modification of known formulas to be used in Saudi Arabia is implemented.

scholarly journals Detecting Apples in the Wild: Potential for Harvest Quantity Estimation

2021 ◽  
Vol 13 (14) ◽  
pp. 8054
Author(s):  
Artur Janowski ◽  
Rafał Kaźmierczak ◽  
Cezary Kowalczyk ◽  
Jakub Szulwic
Keyword(s):  
Image Analysis ◽  
Pilot Study ◽  
Production Management ◽  
Satellite System ◽  
Morphological Operations ◽  
Computational Performance ◽  
Analysis Methods ◽  
Manual Counting ◽  
In The Wild ◽  
Global Navigation Satellite

Knowing the exact number of fruits and trees helps farmers to make better decisions in their orchard production management. The current practice of crop estimation practice often involves manual counting of fruits (before harvesting), which is an extremely time-consuming and costly process. Additionally, this is not practicable for large orchards. Thanks to the changes that have taken place in recent years in the field of image analysis methods and computational performance, it is possible to create solutions for automatic fruit counting based on registered digital images. The pilot study aims to confirm the state of knowledge in the use of three methods (You Only Look Once—YOLO, Viola–Jones—a method based on the synergy of morphological operations of digital imagesand Hough transformation) of image recognition for apple detecting and counting. The study compared the results of three image analysis methods that can be used for counting apple fruits. They were validated, and their results allowed the recommendation of a method based on the YOLO algorithm for the proposed solution. It was based on the use of mass accessible devices (smartphones equipped with a camera with the required accuracy of image acquisition and accurate Global Navigation Satellite System (GNSS) positioning) for orchard owners to count growing apples. In our pilot study, three methods of counting apples were tested to create an automatic system for estimating apple yields in orchards. The test orchard is located at the University of Warmia and Mazury in Olsztyn. The tests were carried out on four trees located in different parts of the orchard. For the tests used, the dataset contained 1102 apple images and 3800 background images without fruits.

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