scholarly journals Computer program to predict visibility of global positioning system (GPS) satellites using an IBM-PC or compatible microcomputer

1987 ◽  
Author(s):  
J.T. Gann
Keyword(s):  
Computer Program ◽  
Global Positioning System ◽  
Positioning System ◽  
Gps Satellites ◽  
Global Positioning ◽  
Ibm Pc

scholarly journals LIDAR Self Driving Car

2021 ◽  
Vol 9 (10) ◽  
pp. 1334-1337
Author(s):  
Soham Phansekar
Keyword(s):  
Global Positioning System ◽  
Electromagnetic Waves ◽  
Traffic Accidents ◽  
Positioning System ◽  
Automated Driving ◽  
Sensing Technology ◽  
Gps Satellites ◽  
Global Positioning ◽  
Total Travel Time ◽  
Car Navigation System

Abstract: Increasing population is the major issue of transportation nowadays. People who live and work in the major cities of the world are faced with increasing levels of congestion, delays, total travel time, costs, frustration, accidents and loss of life. The objective of this project is to help prevent traffic accidents and save people’s time by fundamentally changing car use. The system would have sensors to detect the obstacles and to be able to react according to their position. In this project we have developed an automated driving system which drives the car automatically. We have developed a technology for cars that drives it automatically using LIDAR. This car is capable of sensing the surroundings, navigating and fulfilling the human transportation capabilities without any human input. It continuously tracks the surrounding and if any obstacle is detected vehicle senses and moves around and avoids the obstacle. An autonomous car navigation system based on Global Positioning System (GPS) is a new and promising technology, which uses real time geographical data received from several GPS satellites to calculate longitude, latitude, speed and course to help navigate a car. As we know the development of gps is more improved now the accuracy of gps we can see centimetre also so Like for our car to go at specific inputted location we use this gps technology.Lidar is used for sensing the surroundings. Like radar, lidar is an active remote sensing technology but instead of using radio or microwaves it uses electromagnetic waves. Keywords: Congestion, Traffic Accident, LIDAR sensor, Global Positioning System, Electromagnetic waves

scholarly journals Algorithms of Position and Velocity Estimation in GPS Receivers

2016 ◽  
Vol 23 (1) ◽  
pp. 53-68 ◽  
Author(s):  
Piotr Kaniewski ◽  
Rafał Gil ◽  
Stanisław Konatowski
Keyword(s):  
Global Positioning System ◽  
Velocity Estimation ◽  
Frame Of Reference ◽  
Positioning System ◽  
Gps Receivers ◽  
Extended Kalman Filters ◽  
Navigation Solution ◽  
Gps Satellites ◽  
Global Positioning ◽  
Simulation Results

Abstract Processing of signals in Global Positioning System (GPS) receivers includes numerous signal and data operations leading to calculation of coordinates and velocities of satellites in global Earth-Centered Earth-Fixed (ECEF) frame of reference as well as pseudoranges and delta-ranges between the user and all the tracked GPS satellites. Further processing of these data consists in estimation of the user’s position, velocity and time (PVT) and nowadays it is usually realized by means of an Extended Kalman Filters (EKF). The choice of measuring data processed by the Kalman filter significantly influences the accuracy of navigation solution. In simpler GPS receivers, the estimation of user’s position and velocity is based on pseudoranges only, whereas in more advanced ones delta-ranges are also applied. The paper describes both possible solutions and compares the accuracy of estimation of the user’s position and velocity in both cases. The comparison is based on simulation results, which are included in the paper.

High Accuracy Pseudolite-based Navigation System: Compensating for Right-Hand Circularly Polarized Effect

2006 ◽  
Vol 59 (2) ◽  
pp. 307-320 ◽  
Author(s):  
Haeyoung Jun ◽  
Changdon Kee
Keyword(s):  
Global Positioning System ◽  
Navigation System ◽  
Line Of Sight ◽  
Positioning System ◽  
Phase Measurements ◽  
Circularly Polarized ◽  
Position Accuracy ◽  
Right Hand ◽  
Gps Satellites ◽  
Global Positioning

This paper presents further research on the SNUGL pseudolite-based navigation system presented in this journal in 2003. This system has centimetre-level accuracy, but has an error source arising from right-hand circularly polarized (RHCP) transmissions, unlike outdoor Global Positioning System (GPS). The GPS satellites and pseudolites use RHCP signals, and the polarization affects carrier-phase measurements according to the Line-of-Sight (LOS) vectors from transmitters to receivers. The RHCP error is eliminated by a double differencing process in outdoor GPS, but the error remains in the pseudolite-based system because the LOS vectors from transmitters to a reference and user receivers are different for the close transmitter constellations. This paper shows the RHCP effect on the pseudolite-based navigation system through simulations and experiments. It then shows the RHCP-compensation method improves the measurement and position accuracy by over 10%.

scholarly journals Influence of Ephemeris Error on GPS Single Point Positioning Accuracy

2013 ◽  
Vol 48 (3) ◽  
pp. 125-139
Author(s):  
Ma Lihua ◽  
Meng Wang
Keyword(s):  
Global Positioning System ◽  
Simulation Analysis ◽  
Single Point ◽  
Line Of Sight ◽  
Positioning System ◽  
Gps Satellites ◽  
Time Period ◽  
Global Positioning ◽  
Orbital Position ◽  
The Relationship

Abstract The Global Positioning System (GPS) user makes use of the navigation message transmitted from GPS satellites to achieve its location. Because the receiver uses the satellite's location in position calculations, an ephemeris error, a difference between the expected and actual orbital position of a GPS satellite, reduces user accuracy. The influence extent is decided by the precision of broadcast ephemeris from the control station upload. Simulation analysis with the Yuma almanac show that maximum positioning error exists in the case where the ephemeris error is along the line-of-sight (LOS) direction. Meanwhile, the error is dependent on the relationship between the observer and spatial constellation at some time period.

scholarly journals Positioning with the Global Positioning System

1980 ◽  
Vol 56 ◽  
pp. 191-194
Author(s):  
Clyde C. Goad
Keyword(s):  
Data Collection ◽  
Global Positioning System ◽  
Department Of Defense ◽  
Three Dimensional ◽  
Positioning System ◽  
Relative Positioning ◽  
Recovery Potential ◽  
Gps Satellites ◽  
Global Positioning ◽  
Routine Basis

AbstractThis year (1980) the U. S. Department of Defense has scheduled to have in operation six satellites of the Global Positioning System (GPS), which will provide timing and three dimensional position recovery potential to North America during certain segments of a day. By the mid-eighties, continuous timing and three dimensional recovery from 18 GPS satellites are planned. Although the GPS is designed for fast position recovery to the 10-meter level, extended data collection periods could yield subdecimeter relative positioning on a routine basis.

Accuracy and signal reception of a hand-held Global Positioning System (GPS) receiver

1995 ◽  
Vol 71 (2) ◽  
pp. 192-196 ◽  
Author(s):  
Stephen P. D'Eon
Keyword(s):  
Global Positioning System ◽  
Geographical Information Systems ◽  
Survey Methods ◽  
Mixed Forest ◽  
Geographical Information ◽  
Positioning System ◽  
Gps Survey ◽  
Gps Satellites ◽  
Forest Survey ◽  
Global Positioning

Accurate and precise reporting of forest survey locations is required to integrate forest survey data with Geographical Information Systems. The accuracies of five Global Positioning System (GPS) survey methods using a hand-held receiver were tested in a mixed forest of trembling aspen and spruce. Accuracy improved by eliminating positions obtained under poor satellite configurations and by using position averaging methods. Single fix positions, taking as little as two minutes to obtain, yielded better than 100m accuracy more than 80% of the time. Allowing the receiver to continuously collect fixes for 15 to 30 minutes and then averaging the fixes yielded a median position error of 17 m. Sixty one stands representing a diversity of cover types, canopy heights, and crown closure in the Petawawa Research Forest were tested during June and July of 1992 for canopy interference with GPS signals. A GPS position was obtained under the canopy in 74% of the stands. Launches of additional GPS satellites since the summer of 1992 have further improved the probability of obtaining accurate geographical positions under forest canopies. Key words: global positioning system, position accuracy, signal reception, canopy interference

GPS Satellite Advancements and its Future

2020 ◽  
Vol 07 (01) ◽  
pp. 1-4
Author(s):  
Gopal Kochhar ◽  
Keyword(s):  
Comparative Study ◽  
Global Positioning System ◽  
Positioning System ◽  
Tracking Systems ◽  
Gps Satellites ◽  
Global Positioning ◽  
The Future ◽  
The Comparative Study

This paper gives an brief introduction of global positioning system, its generations, the future and progressions that are attained by the GPS and tracking systems. The latest usage and the comparative study of the GPS satellites that are launched and are operational till date.

scholarly journals Optical Astrometry and the Global Positioning System

1991 ◽  
Vol 127 ◽  
pp. 284-287
Author(s):  
P.C. Kammeyer ◽  
H.F. Fliegel ◽  
R.S. Harrington
Keyword(s):  
Global Positioning System ◽  
Optical Sensors ◽  
Optical Observations ◽  
Line Of Sight ◽  
Positioning System ◽  
Charge Coupled Device ◽  
Gps Satellites ◽  
Global Positioning ◽  
Device Technology ◽  
Stellar Background

AbstractAstrometric accuracies of a few tens of milliarcseconds are expected to be attainable within five years by calibrating astrograph plates with optical observations of Global Positioning System (GPS) satellites against a stellar background. The line of sight from an observer on the Earth’s surface to a GPS satellite may be calculated with high accuracy. Motion on each day of the line of sight to the satellite and changes from day to day in the apparent path of the satellite are sufficiently slow to make it possible to reduce atmospheric errors by averaging. Advanced ground-based optical sensors, probably using charge coupled device technology, will be required for GPS optical astrometry.

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