scholarly journals A Planar Quasi-Yagi For Next Generation Wireless Communication Systems

2008 ◽  
Author(s):  
Mai Thanh Nga ◽  
Vu Van Yem ◽  
Nguyen Huu Thanh ◽  
Pham Duy Phong
Keyword(s):  
Global Positioning System ◽  
Communication Systems ◽  
Cell Phone ◽  
Wireless Communication Systems ◽  
Optimal Model ◽  
Low Profile ◽  
Yagi Antenna ◽  
Global Positioning ◽  
Universal Mobile Telecommunications System ◽  
Better Than

UMTS (Universal Mobile Telecommunications System) technology is one of the third-generation (3G) cell phone technologies, which is also being developed into a 4G technology. Although UMTS2001 is the most widely-deployed UMTS band, some countries utilize 1900 MHz instead. Besides, the co-existing GPS (Global Positioning System) operates at the frequency of 1575 MHz. Thus, a desirable antenna in UMTS systems needs to cover both of two bands in order to operate in various devices. This paper will propound an antenna covering the range of frequencies from 1.53 GHz to 2.53 GHz that includes 1.575 GHz, 1.8 GHz, 1.9 GHz ,and 2.1 GHz. The developed quasi-Yagi antenna has a simple-low profile and achieves a bandwidth of 48%, a front- to- back ratio of 19 dB, a gain of 6dBi, and an efficiency of better than 78% at 2.1GHz. In this paper, the study on effects of parameters of the antenna is also investigated to achieve optimal model.

scholarly journals Localization of Autonomous Robot in an Urban Area Based on SURF Feature Extraction of Images

2020 ◽  
Vol 11 (4) ◽  
pp. 84-111
Author(s):  
Abu Sadat Mohammed Yasin ◽  
Md. Majharul Haque ◽  
Md. Nasim Adnan ◽  
Sonia Rahnuma ◽  
Anowar Hossain ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Image Matching ◽  
Autonomous Robots ◽  
Network Connectivity ◽  
Specific Area ◽  
Autonomous Robot ◽  
Elapsed Time ◽  
Global Positioning ◽  
The Given ◽  
Better Than

An autonomous robot is now an internationally discussed topic to ease the life of humans. Localization and movement are two rudimentary necessities of the autonomous robots before accomplishing any job. So, many researchers have proposed methods of localization using external tools like network connectivity, global positioning system (GPS), etc. However, if these tools are lost, either the movement will be paused, or the robot will be derailed from the actual mission. In these circumstances, the authors propose an approach to localize an autonomous robot in a specific area using the given set of images without external help. The image database has been prepared and kept in the internal memory of robot so that image matching can be done quickly. The localization method has been accomplished using three algorithms: (1) SURF, (2) ICP-BP, and (3) EMD. In the evaluation, SURF has been found better than ICP-BP and EMD in terms of accuracy and elapsed time. The authors believe that the proposed method will add value to other methods using some external tools even when those tools are unavailable.

Analytical Modeling and its Validation for Data Acquisition of ADS-B System

2014 ◽  
Vol 641-642 ◽  
pp. 1303-1306 ◽  
Author(s):  
Jian Hui Wang
Keyword(s):  
Global Positioning System ◽  
Analytical Modeling ◽  
Quality Evaluation ◽  
Data Availability ◽  
Civil Aviation ◽  
Evaluation Indexes ◽  
Navigation Data ◽  
Global Positioning ◽  
Data Source ◽  
Better Than

Based on the accuracy and integrity quality evaluation indexes of ADS-B navigation data, this paper foucses on the analytical modeling of ADS-B navigation data source under the global positioning system (GPS) and Compass system. The factors related to accuracy and integrity of ADS-B are derived and simulated, which include the position estimated uncertainty (EPU) and horizontal position integrity containing radius (RC). It is the first to give the quality index levels of the ADS-B horizontal data source in Tianjin under GPS and Compass. The simulation results show that ADS-B navigation data availability under Compass not only meet the lowest requirements recommended by the civil aviation administration of China (CAAC), but also is better than under Compass. The results derived from this paper provide the theoretic support for the implementation of ADS-B in Tianjin Binhai international airport and other areas of China. At the same time, Compass being navigation source increases reliability and security for ADS-B implementation of our country.

The Global Positioning System

1980 ◽  
Vol 294 (1410) ◽  
pp. 395-406 ◽  
Keyword(s):  
United States ◽  
Travel Time ◽  
Global Positioning System ◽  
The United States ◽  
Positioning System ◽  
Absolute Position ◽  
Southwestern Part ◽  
Ground Station ◽  
Global Positioning ◽  
Better Than

The Navstar Global Positioning System, proposed for deployment in 1985, will have eight satellites equally spaced in each of three orbit planes at an inclination of 63°. Since the satellites will be in circular, 20000 km (12 h period), orbits and the nodes of the three orbit planes will be equally spaced, at least four satellites will be in view at any location. Range to three of the satellites, computed from the travel time of signal from the satellite to the ground, would give the position of the ground receiver. The measurement to the fourth satellite is required to synchronize the ground station clock with the satellite to provide a sufficiently accurate travel time. In order that the system may be demonstrated in early 1979, six satellites are now being launched into orbits that will provide the operational configuration over the southwestern part of the United States for a few hours each day. The accuracy of the instantaneous absolute position is expected to be 10 m. The relative position of two stationary receivers could be determined to 1 m accuracy in a few minutes even if the receivers are separated by 1000 km. Relative positions could be determined to better than 10 cm accuracy within a day.

A Novel Energy Efficient Joint Dynamic Emissive Location-Based Routing Scheme for SOFAR Channel Underwater Sensor Networks

2013 ◽  
Vol 284-287 ◽  
pp. 2001-2004 ◽  
Author(s):  
Chia Sheng Tsai ◽  
Chich Fu Yang
Keyword(s):  
Global Positioning System ◽  
Routing Protocol ◽  
Routing Protocols ◽  
Energy Efficient ◽  
Sea Surface ◽  
Underwater Sensor Networks ◽  
Detection And Identification ◽  
Global Positioning ◽  
Reduced Costs ◽  
Better Than

The Underwater Sensor Network (UWSN) could be recorded by hydrophones suspended in the channel as earthquake monitors by seismic events on or below the seafloor generated energy. In this paper, we present a novel position of sensor devices and routing protocol towards short for Sound Fixing and Ranging channel (SOFAR) for Sound Fixing and Ranging channel technologies, which could save transmission power. The sound speed also increases towards the warmer sea surface with temperature. Thus we use the oceanography to find more efficient ways of utilizing routing protocol and in to obtain more effective detection and identification capabilities for underwater sources. We present an adaptive location-based routing protocol which can overcome the location based UWSN without Global Positioning System (GPS) position. It reduced costs of deployment in long range propagation. The performances are measured according to the energy consumption per bit in which the result of simulator is better than other routing protocols such as FBR.

scholarly journals Introduction of JD 19: Nutation

1995 ◽  
Vol 10 ◽  
pp. 209-213
Author(s):  
V. Dehant
Keyword(s):  
Global Positioning System ◽  
Laser Ranging ◽  
Lunar Laser Ranging ◽  
Long Baseline ◽  
Lunar Laser ◽  
Global Positioning ◽  
Nutation Series ◽  
Precise Time ◽  
Better Than ◽  
Precession Constant

Due to both precise time measurements and precise geodetic positioning methods (like Very Long Baseline Interferometry (VLBI), Lunar Laser Ranging (LLR), Satellite Laser Ranging (SLR) and Global Positioning System (GPS)), the position of the instantaneous axis of the Earth’s rotation in space is measured with a precision better than a tenth of milliarcsecond. Simultaneously the amplitudes of the nutations of the Celestial Ephemeris Pole (CEP) deduced from the observations, i.e. the periodic motions in space of the CEP due to the luni-solar attraction or to other planetary attractions, have also been improved. However, these observed nutation amplitudes differ with respect to the computated ones based on an elliptical, uniformly rotating and deformable Earth responding to the lunar and solar attractions, as adopted by the IAU in 1980. The first session on “Observations and data reduction” dealt with Earth’s orientation observations and data analysis for deriving precession and nutations, as well as the associated residuals with respect to the adopted precession constant and nutation series. Comparisons between the different results have been presented including in-phase and out-of-phase components of the prograde and retrograde nutations or of nutations in longitude and in obliquity (see Session 1 of our JD: Newhall et al., McCarthy and Luzum, Herring, and Session 2: Gross). These differences “observed - adopted” nutations achieve several milliarcseconds and exhibit periodic as well as secular characteristics.

scholarly journals 1996–2017 GPS position time series, velocities and quality measures for the CORS Network

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jarir Saleh ◽  
Sungpil Yoon ◽  
Kevin Choi ◽  
Lijuan Sun ◽  
Richard Snay ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Term Stability ◽  
Long Term Stability ◽  
Velocity Models ◽  
Daily Data ◽  
The Us ◽  
Global Positioning ◽  
Position Time Series ◽  
Better Than

Abstract The CORS network is a volunteer-based network of Global Positioning System reference stations located mainly in the US and its territories. We discuss the most recent comprehensive reprocessing of all GPS data collected via this network since 1996. Daily data for GPS weeks 834 through 1933 were reprocessed leading to epoch 2010.0 coordinates and velocities of 3049 stations aligned to IGS14. The updated realization of the US National Spatial Reference System derived in this work has been in use since late 2019. As a validation of the results, the derived velocity field is compared to several other solutions and to three regional geophysical and geodetic velocity models. These comparisons uncovered unstable stations which move differently than the regional kinematics around them. Once these are ignored, we estimate the horizontal and vertical stability of this updated realization to be better than ∼0.3 and ∼0.6 mm/year, respectively. We use the position residuals and estimated uncertainties from this reprocessing to derive long-term stability measures for all active stations serving longer than 3 years. These measures exposed ∼60 CORS with the poorest long-term stability, which have been consequently excluded from serving as mapping control.

scholarly journals Sistem Monitoring Konversi Wifi-RSSI Menjadi Jarak Antar Device dan Router Menggunakan Node-Red Pada Pengembangan Sistem Navigasi Dalam Ruang

2021 ◽  
Vol 1 ◽  
pp. 32-37
Author(s):  
Rifqi Nafis Mubaroq ◽  
Nina Siti Aminah
Keyword(s):  
Global Positioning System ◽  
Raspberry Pi ◽  
Positioning System ◽  
Actual Distance ◽  
Comparison Results ◽  
Graph Match ◽  
Global Positioning ◽  
Narrow Space ◽  
Narrow Area ◽  
Better Than

A global positioning system (GPS) is often used as a tool for determining direction and positioning. However, GPS is weak in estimating the error, which is quite large at the actual distance, so positioning in a narrow area cannot work well. Therefore, a better method is needed to be used as a narrow-navigation system. This study aimed to determine whether RSSI has a better error than GPS for navigation devices in a narrow space or area. The method used was plotting graphs using Ms. Excel and determining the value of R square. The RSSI value was obtained through the Esp8266 device and then sent to the server via the MQTT protocol and converted using Node-Red on the Raspberry Pi. The comparison results of the Esp8266 device RSSI graph match the Laptop RSSI device as a reference. The match between the relative distance to the RSSI with the actual distance shows a 3.3-33% error. This result is considered much better than the GPS error.

scholarly journals A Comparative Study on Digital Encryption Algorithms

2018 ◽  
pp. 371-375
Author(s):  
Harsh Shah ◽  
Vipul Sharma ◽  
Dharmik Panchal ◽  
Sumeet Patel ◽  
Dr. Sheshang Degadwal
Keyword(s):  
Comparative Study ◽  
Global Positioning System ◽  
Cell Phone ◽  
Positioning System ◽  
Verbal Instructions ◽  
Global Positioning ◽  
Encryption Algorithms

This is a project to help someone with advanced Alzheimer. It is a GPS (Global Positioning System) unit for Alzheimer patients. Alzheimer patients often get lost, or wander off. They forget familiar land marks. It works like this: The patient carries a combination cell phone and GPS unit on a necklace or lag band. When the patient touches the unit, or holds it, it starts giving verbal instructions on how to walk home, repeating as necessary. If the patient is too far from home to walk, it phones home and reports the location of the patient, using street names, as well as latitude and longitude. Note that there are no buttons to push and nothing to look at on the unit. It is activated just by touching it.

scholarly journals Radiation effect of fractal sierpinski square patch antenna

2020 ◽  
Vol 10 (5) ◽  
pp. 5329
Author(s):  
Khalid Hussein Kuther ◽  
Israa Hazem Ali ◽  
Riyadh Khlf Ahmed
Keyword(s):  
Electromagnetic Fields ◽  
Global Positioning System ◽  
Patch Antenna ◽  
Communication Systems ◽  
Radiation Effect ◽  
Electronic Devices ◽  
Frequency Range ◽  
Research Article ◽  
Global Positioning ◽  
Human Finger

Biological tissue interaction with Electromagnetic fields became one of the interesting studies in the last years. Wide variety wireless electronic devices are emerged in day to day life each providing a wireless connection for a certain service such as Global Positioning System, broadcasting systems, mobile communication systems, and networking. In this research article, Fractal Sierpinski Square Patch Antenna is proposed and simulated to operate over L1 frequency range of 1.575 GHz for GPS applications using CST studio Suite where the proposed antenna has been investigated on Carpet shaped substrate made of Arlon 250 AD lossy. The dielectric constant equals to 2.5 and thickness of 1.6 mm. Thickness of patch is 0.6 mm. Also, the electromagnetic fields absorption on the human fingers is investigated where SAR levels are calculated for 0th, 1st, 2nd and 3rd iteration of the Fractal Sierpinski Square Patch Antenna. The results reported that the SAR limit of human finger tissue is enhanced with increasing the number of iteration.

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