Gps, Glonass and Beidou) Obsevation for Positioning
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
GPS and GLONASS Vector Tracking for Navigation in Challenging Signal Environments
GPS and GLONASS Vector Tracking for Navigation in Challenging Signal Environments Tanner Watts, Scott Martin, and David Bevly GPS and Vehicle Dynamics Lab – Auburn University October 29, 2019 2 GPS Applications (GAVLAB) Truck Platooning Good GPS Signal Environment Autonomous Vehicles Precise Timing UAVs 3 Challenging Signal Environments • Navigation demand increasing in the following areas: • Cites/Urban Areas • Forests/Dense Canopies • Blockages (signal attenuation) • Reflections (multipath) 4 Contested Signal Environments • Signal environment may experience interference • Jamming . Transmits “noise” signals to receiver . Effectively blocks out GPS • Spoofing . Transmits fake GPS signals to receiver . Tricks or may control the receiver 5 Contested Signal Environments • These interference devices are becoming more accessible GPS Jammers GPS Simulators 6 Traditional GPS Receiver Signals processed individually: • Known as Scalar Tracking • Delay Lock Loop (DLL) for Code • Phase Lock Loop (PLL) for Carrier 7 Traditional GPS Receiver • Feedback loops fail in the presence of significant noise • Especially at high dynamics Attenuated or Distorted Satellite Signal 8 Vector Tracking Receiver • Process signals together through the navigation solution • Channels track each other’s signals together • 2-6 dB improvement • Requires scalar tracking initially 9 Vector Tracking Receiver Vector Delay Lock Loop (VDLL) • Code tracking coupled to position navigation • DLL discriminators inputted into estimator • Code frequencies commanded by predicted pseudoranges -
Comparing Four Methods of Correcting GPS Data: DGPS, WAAS, L-Band, and Postprocessing Dick Karsky, Project Leader
United States Department of Agriculture Engineering Forest Service Technology & Development Program July 2004 0471-2307–MTDC 2200/2300/2400/3400/5100/5300/5400/ 6700/7100 Comparing Four Methods of Correcting GPS Data: DGPS, WAAS, L-Band, and Postprocessing Dick Karsky, Project Leader he global positioning system (GPS) of satellites DGPS Beacon Corrections allows persons with standard GPS receivers to know where they are with an accuracy of 5 meters The U.S. Coast Guard has installed two control centers Tor so. When more precise locations are needed, and more than 60 beacon stations along the coastal errors (table 1) in GPS data must be corrected. A waterways and in the interior United States to transmit number of ways of correcting GPS data have been DGPS correction data that can improve GPS accuracy. developed. Some can correct the data in realtime The beacon stations use marine radio beacon fre- (differential GPS and the wide area augmentation quencies to transmit correction data to the remote GPS system). Others apply the corrections after the GPS receiver. The correction data typically provides 1- to data has been collected (postprocessing). 5-meter accuracy in real time. In theory, all methods of correction should yield similar In principle, this process is quite simple. A GPS receiver results. However, because of the location of different normally calculates its position by measuring the time it reference stations, and the equipment used at those takes for a signal from a satellite to reach its position. stations, the different methods do produce different Because the GPS receiver knows exactly where results. -
Geodesy in the 21St Century
Eos, Vol. 90, No. 18, 5 May 2009 VOLUME 90 NUMBER 18 5 MAY 2009 EOS, TRANSACTIONS, AMERICAN GEOPHYSICAL UNION PAGES 153–164 geophysical discoveries, the basic under- Geodesy in the 21st Century standing of earthquake mechanics known as the “elastic rebound theory” [Reid, 1910], PAGES 153–155 Geodesy and the Space Era was established by analyzing geodetic mea- surements before and after the 1906 San From flat Earth, to round Earth, to a rough Geodesy, like many scientific fields, is Francisco earthquakes. and oblate Earth, people’s understanding of technology driven. Over the centuries, it In 1957, the Soviet Union launched the the shape of our planet and its landscapes has developed as an engineering discipline artificial satellite Sputnik, ushering the world has changed dramatically over the course because of its practical applications. By the into the space era. During the first 5 decades of history. These advances in geodesy— early 1900s, scientists and cartographers of the space era, space geodetic technolo- the study of Earth’s size, shape, orientation, began to use triangulation and leveling mea- gies developed rapidly. The idea behind and gravitational field, and the variations surements to record surface deformation space geodetic measurements is simple: Dis- of these quantities over time—developed associated with earthquakes and volcanoes. tance or phase measurements conducted because of humans’ curiosity about the For example, one of the most important between Earth’s surface and objects in Earth and because of geodesy’s application to navigation, surveying, and mapping, all of which were very practical areas that ben- efited society. -
Solar Radiation Pressure Models for Beidou-3 I2-S Satellite: Comparison and Augmentation
remote sensing Article Solar Radiation Pressure Models for BeiDou-3 I2-S Satellite: Comparison and Augmentation Chen Wang 1, Jing Guo 1,2 ID , Qile Zhao 1,3,* and Jingnan Liu 1,3 1 GNSS Research Center, Wuhan University, 129 Luoyu Road, Wuhan 430079, China; [email protected] (C.W.); [email protected] (J.G.); [email protected] (J.L.) 2 School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK 3 Collaborative Innovation Center of Geospatial Technology, Wuhan University, 129 Luoyu Road, Wuhan 430079, China * Correspondence: [email protected]; Tel.: +86-027-6877-7227 Received: 22 December 2017; Accepted: 15 January 2018; Published: 16 January 2018 Abstract: As one of the most essential modeling aspects for precise orbit determination, solar radiation pressure (SRP) is the largest non-gravitational force acting on a navigation satellite. This study focuses on SRP modeling of the BeiDou-3 experimental satellite I2-S (PRN C32), for which an obvious modeling deficiency that is related to SRP was formerly identified. The satellite laser ranging (SLR) validation demonstrated that the orbit of BeiDou-3 I2-S determined with empirical 5-parameter Extended CODE (Center for Orbit Determination in Europe) Orbit Model (ECOM1) has the sun elongation angle (# angle) dependent systematic error, as well as a bias of approximately −16.9 cm. Similar performance has been identified for European Galileo and Japanese QZSS Michibiki satellite as well, and can be reduced with the extended ECOM model (ECOM2), or by using the a priori SRP model to augment ECOM1. In this study, the performances of the widely used SRP models for GNSS (Global Navigation Satellite System) satellites, i.e., ECOM1, ECOM2, and adjustable box-wing model have been compared and analyzed for BeiDou-3 I2-S satellite. -
GLONASS & GPS HW Designs
GLONASS & GPS HW designs Recommendations with u-blox 6 GPS receivers Application Note Abstract This document provides design recommendations for GLONASS & GPS HW designs with u-blox 6 module or chip designs. u-blox AG Zürcherstrasse 68 8800 Thalwil Switzerland www.u-blox.com Phone +41 44 722 7444 Fax +41 44 722 7447 [email protected] GLONASS & GPS HW designs - Application Note Document Information Title GLONASS & GPS HW designs Subtitle Recommendations with u-blox 6 GPS receivers Document type Application Note Document number GPS.G6-CS-10005 Document status Preliminary This document and the use of any information contained therein, is subject to the acceptance of the u-blox terms and conditions. They can be downloaded from www.u-blox.com. u-blox makes no warranties based on the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and product descriptions at any time without notice. u-blox reserves all rights to this document and the information contained herein. Reproduction, use or disclosure to third parties without express permission is strictly prohibited. Copyright © 2011, u-blox AG. ® u-blox is a registered trademark of u-blox Holding AG in the EU and other countries. GPS.G6-CS-10005 Page 2 of 16 GLONASS & GPS HW designs - Application Note Contents Contents .............................................................................................................................. 3 1 Introduction ................................................................................................................. -
AEN-88: the Global Positioning System
AEN-88 The Global Positioning System Tim Stombaugh, Doug McLaren, and Ben Koostra Introduction cies. The civilian access (C/A) code is transmitted on L1 and is The Global Positioning System (GPS) is quickly becoming freely available to any user. The precise (P) code is transmitted part of the fabric of everyday life. Beyond recreational activities on L1 and L2. This code is scrambled and can be used only by such as boating and backpacking, GPS receivers are becoming a the U.S. military and other authorized users. very important tool to such industries as agriculture, transporta- tion, and surveying. Very soon, every cell phone will incorporate Using Triangulation GPS technology to aid fi rst responders in answering emergency To calculate a position, a GPS receiver uses a principle called calls. triangulation. Triangulation is a method for determining a posi- GPS is a satellite-based radio navigation system. Users any- tion based on the distance from other points or objects that have where on the surface of the earth (or in space around the earth) known locations. In the case of GPS, the location of each satellite with a GPS receiver can determine their geographic position is accurately known. A GPS receiver measures its distance from in latitude (north-south), longitude (east-west), and elevation. each satellite in view above the horizon. Latitude and longitude are usually given in units of degrees To illustrate the concept of triangulation, consider one satel- (sometimes delineated to degrees, minutes, and seconds); eleva- lite that is at a precisely known location (Figure 1). If a GPS tion is usually given in distance units above a reference such as receiver can determine its distance from that satellite, it will have mean sea level or the geoid, which is a model of the shape of the narrowed its location to somewhere on a sphere that distance earth. -
GPS Applications in Space
Space Situational Awareness 2015: GPS Applications in Space James J. Miller, Deputy Director Policy & Strategic Communications Division May 13, 2015 GPS Extends the Reach of NASA Networks to Enable New Space Ops, Science, and Exploration Apps GPS Relative Navigation is used for Rendezvous to ISS GPS PNT Services Enable: • Attitude Determination: Use of GPS enables some missions to meet their attitude determination requirements, such as ISS • Real-time On-Board Navigation: Enables new methods of spaceflight ops such as rendezvous & docking, station- keeping, precision formation flying, and GEO satellite servicing • Earth Sciences: GPS used as a remote sensing tool supports atmospheric and ionospheric sciences, geodesy, and geodynamics -- from monitoring sea levels and ice melt to measuring the gravity field ESA ATV 1st mission JAXA’s HTV 1st mission Commercial Cargo Resupply to ISS in 2008 to ISS in 2009 (Space-X & Cygnus), 2012+ 2 Growing GPS Uses in Space: Space Operations & Science • NASA strategic navigation requirements for science and 20-Year Worldwide Space Mission space ops continue to grow, especially as higher Projections by Orbit Type* precisions are needed for more complex operations in all space domains 1% 5% Low Earth Orbit • Nearly 60%* of projected worldwide space missions 27% Medium Earth Orbit over the next 20 years will operate in LEO 59% GeoSynchronous Orbit – That is, inside the Terrestrial Service Volume (TSV) 8% Highly Elliptical Orbit Cislunar / Interplanetary • An additional 35%* of these space missions that will operate at higher altitudes will remain at or below GEO – That is, inside the GPS/GNSS Space Service Volume (SSV) Highly Elliptical Orbits**: • In summary, approximately 95% of projected Example: NASA MMS 4- worldwide space missions over the next 20 years will satellite constellation. -
An Overview of Global Positioning System (GPS)
Technical Article February 2012 | page 1 An Overview of Global Positioning System (GPS) The Global Positioning System (GPS) is a satellite–based radio–navigation system. GPS provides reliable positioning, navigation, and timing services to users on a continuous worldwide basis. The satellite system was built by the United States, but its services are freely available to everyone on the planet. For anyone with a GPS receiver, the system provides location and time. GPS provides accurate location and time information for an unlimited number of people in all weather, day or night, anywhere in the world. The GPS is made up of three parts: satellites orbiting the Earth; control and monitoring stations on Earth; and the GPS receivers (either stand–alone devices or integrated sub–systems) operated by users. GPS satellites broadcast continuous signals which are picked up and identified by GPS receivers. Each GPS receiver then provides three–dimensional location information (latitude, longitude, and altitude), plus the current time. Equipped with a GPS receiver, any user can accurately locate where they are and easily navigate to where they want to go, whether walking, driving, flying, or boating. GPS has become an important part of transportation systems worldwide, providing navigation for aviation, ground, and maritime operations. Disaster relief and emergency service agencies depend upon GPS for location and timing capabilities in their life–saving missions. Everyday activities such as banking, mobile phone operations, and even the control of power grids, are facilitated by the accurate timing provided by GPS. Farmers, surveyors, geologists and countless others perform their work more efficiently, safely, economically, and accurately using the free and open GPS signals. -
Coordinate Systems in Geodesy
COORDINATE SYSTEMS IN GEODESY E. J. KRAKIWSKY D. E. WELLS May 1971 TECHNICALLECTURE NOTES REPORT NO.NO. 21716 COORDINATE SYSTElVIS IN GEODESY E.J. Krakiwsky D.E. \Vells Department of Geodesy and Geomatics Engineering University of New Brunswick P.O. Box 4400 Fredericton, N .B. Canada E3B 5A3 May 1971 Latest Reprinting January 1998 PREFACE In order to make our extensive series of lecture notes more readily available, we have scanned the old master copies and produced electronic versions in Portable Document Format. The quality of the images varies depending on the quality of the originals. The images have not been converted to searchable text. TABLE OF CONTENTS page LIST OF ILLUSTRATIONS iv LIST OF TABLES . vi l. INTRODUCTION l 1.1 Poles~ Planes and -~es 4 1.2 Universal and Sidereal Time 6 1.3 Coordinate Systems in Geodesy . 7 2. TERRESTRIAL COORDINATE SYSTEMS 9 2.1 Terrestrial Geocentric Systems • . 9 2.1.1 Polar Motion and Irregular Rotation of the Earth • . • • . • • • • . 10 2.1.2 Average and Instantaneous Terrestrial Systems • 12 2.1. 3 Geodetic Systems • • • • • • • • • • . 1 17 2.2 Relationship between Cartesian and Curvilinear Coordinates • • • • • • • . • • 19 2.2.1 Cartesian and Curvilinear Coordinates of a Point on the Reference Ellipsoid • • • • • 19 2.2.2 The Position Vector in Terms of the Geodetic Latitude • • • • • • • • • • • • • • • • • • • 22 2.2.3 Th~ Position Vector in Terms of the Geocentric and Reduced Latitudes . • • • • • • • • • • • 27 2.2.4 Relationships between Geodetic, Geocentric and Reduced Latitudes • . • • • • • • • • • • 28 2.2.5 The Position Vector of a Point Above the Reference Ellipsoid . • • . • • • • • • . .• 28 2.2.6 Transformation from Average Terrestrial Cartesian to Geodetic Coordinates • 31 2.3 Geodetic Datums 33 2.3.1 Datum Position Parameters . -
Satellite Geodesy: Foundations, Methods and Applications, Second Edition
Satellite Geodesy: Foundations, Methods and Applications, Second Edition By Günter Seeber, 589 pages, 281 figures, 64 tables, ISBN: 3-11-017549-5, published by Walter de Gruyter GmbH & Co., Berlin, 2003 The first edition of this book came out in 1993, when it made an enormous contribution to the field. It brought together in one volume a vast amount Günter Seeber of information scattered throughout the geodetic literature on satellite mis Satellite Geodesy sions, observables, mathematical models and applications. In the inter 2nd Edition vening ten years the field has devel oped at an astonishing rate, and the new edition has been completely revised to take this into account. Apart from a review of the historical development of the field, the book is divided into three main sections. The first part is a general introduction to the fundamentals of the subject: refer ence frames; time systems; signal propagation; Keplerian models of satel de Gruyter lite motion; orbit perturbations; orbit determination; orbit types and constel lations. The second section, which contributes to the fields of terrestrial comprises the major part of the book, and marine physical and geometrical is a detailed description of the principal geodesy, navigation and geodynamics. techniques falling under the umbrella of satellite geodesy. Those covered The book is written in an accessible are: optical techniques; Doppler posi style, particularly given the technical tioning; Global Navigation Satellite nature of the content, and is therefore Systems (GNSS, incorporating GPS, useful to a wide community of readers. GLONASS and GALILEO), Satellite Every topic has extensive and up to Laser Ranging (SLR), satellite altime date references allowing for further try, gravity field missions, Very Long investigation where necessary. -
Multi-GNSS Kinematic Precise Point Positioning: Some Results in South Korea
JPNT 6(1), 35-41 (2017) Journal of Positioning, https://doi.org/10.11003/JPNT.2017.6.1.35 JPNT Navigation, and Timing Multi-GNSS Kinematic Precise Point Positioning: Some Results in South Korea Byung-Kyu Choi1†, Chang-Hyun Cho1, Sang Jeong Lee2 1Space Geodesy Group, Korea Astronomy and Space Science Institute, Daejeon 305-348, Korea 2Department of Electronics Engineering, Chungnam National University, Daejeon 305-764, Korea ABSTRACT Precise Point Positioning (PPP) method is based on dual-frequency data of Global Navigation Satellite Systems (GNSS). The recent multi-constellations GNSS (multi-GNSS) enable us to bring great opportunities for enhanced precise positioning, navigation, and timing. In the paper, the multi-GNSS PPP with a combination of four systems (GPS, GLONASS, Galileo, and BeiDou) is analyzed to evaluate the improvement on positioning accuracy and convergence time. GNSS observations obtained from DAEJ reference station in South Korea are processed with both the multi-GNSS PPP and the GPS-only PPP. The performance of multi-GNSS PPP is not dramatically improved when compared to that of GPS only PPP. Its performance could be affected by the orbit errors of BeiDou geostationary satellites. However, multi-GNSS PPP can significantly improve the convergence speed of GPS-only PPP in terms of position accuracy. Keywords: PPP, multi-GNSS, Positioning accuracy, convergence speed 1. INTRODUCTION Positioning System (GPS) has been modernized steadily and Russia has also operated the GLObal NAvigation Satellite Precise Point Positioning (PPP) using the Global Navigation System (GLONASS) stably since 2012. Furthermore, the EU Satellite System (GNSS) can determine positioning of users has launched the 12th Galileo satellite recently indicating from several millimeters to a few centimeters (cm) if dual- the global satellite navigation system is now entering a final frequency observation data are employed (Zumberge et al. -
Some Problems Concerned with the Geodetic Use of High Precision Altimeter Data
Reports of the Department of Geodetic Science Report No. 237 SOME PROBLEMS CONCERNED WITH THE GEODETIC USE OF HIGH PRECISION ALTIMETER DATA D. by cc w D.Lelgemann H.m ko 0 o Prepared for National Aeronautics and Space Administration Goddard Space Flight Center ,a0 Greenbelt, Maryland 20770 u to r) = H 'V _U Al Grant No. NGR 36-008-161 M t OSURF Project No. 3210 pi ZLn C0 Oa)n :.)W. U0Q. 'no 0C The Ohio State University M10 E-14J Research Foundation 94I Columbus, Ohio 43212 0 aH January, 1976 Reports of the Departme" -4 f-,no, Science Report No. 237 Some Problems Concerned with the Geodetic Use of High Precision Altimeter Data by D. Lolgenann Prepared for National Aeronautics and Space Adminisfrati Goddard Space Flight Cente7 Greenbelt, Maryland 26770 Grant No. NGR 36-008-161 OSURF Project No. 3210 The Ohio State University Research Foundation Columbus, Ohio 43212 January, 1976 Foreword This report was prepared by Dr. D. Lelgemann, Visiting Research Associate, Department of Geodetic Science, The Ohio State University, and Wissenschafti. Rat at the Institut fdr Angewandte Geodiisie, Federal Repub lic of Germany. This work was supported, in part, through NASA Grant NGR 36-008-161, The Ohio State University Research Foundation Project No. 3210, which is under the direction of Professor Richard H. Rapp. The grant supporting this research is administered through the Goddard Space Flight Center, Greenbelt, Maryland with Mr. James Marsh as Technical Officer. The author is particularly grateful to Professor Richard H. Rapp for helpful discussions and to Deborah Lucas for her careful typing.