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GNSS & Mapping. GNSS (Global Navigation Satellite System) GIS (Geographic Information System)

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GNSS GLOBAL NAVIGATION SATELLITE SYSTEM

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GNSS GPS GLONASS GALILEO BEIDOU IRNSS GPS (USA)- Global Positioning System GLONASS (Russia)- Global Navigation Satellite System GALILEO (Europe)- European Satellite Navigation system BEIDOU (China)- Beidou Satellite Navigation and Positioning System IRNSS (India)- Indian Regional Navigational Satellite System

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OUR GNSS (GPS) PRODUCTS Consumer Product High-end Product

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Product History 1993-1995 Magellan Nav 5200

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1995-1998

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1998-2002 Magellan Nav 1200

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2002-2004 Magellan Meridian Magellan Sport Trck

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2004-2008 explorist-gps-family

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2008-2010 Triton-gps-family

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Since 2010 Explirist x10-gps-family Explirist x10-GIS-family Novatel High-end GNSS -family

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History of the GPS Delta rocket launch

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Main Segments

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Space Techniques There are several satellite techniques Height above earth (km) Satellite types 150 - 1,500 Remote sensing 1,500 - 20,000 Geodetic (GNSS) >36,000 Communication

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(1) Space segment 24 satellite vehicles Six orbital planes Inclined 55 o with respect to equator Orbits separated by 60 o 20,200 km elevation above Earth Orbital period of 11 hr 55 min Five to eight satellites visible from any point on Earth Block I Satellite Vehicle

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GPS Satellite Vehicle Weight 2370 pounds Height 16.25 feet Width 38.025 feet including wing span Design life10 years Block IIR satellite vehicle

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DELTA6000/7000 Launch Vehicle USA

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The GPS Constellation

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(2) Ground control segment Master control station AFB, Colorado Five monitor stations Three ground antennas Backup control system

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Ground control segment

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GPS antennas & receiver/processors Position Velocity Precise timing Used by Aircraft Ground vehicles Ships Individuals User segment

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How does GPS work? Satellite ranging Satellite locations Satellite to user distance Need four satellites to determine position Distance measurement Radio signal traveling at speed of light Measure time from satellite to user

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The GPS Measurements PSEUDO-RANGES MEASUREMENT CARRIER PHASE MEASUREMENTS

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PSEUDO-RANGES MEASUREMENT Distance to a satellite is determined by measuring how long a radio signal takes to reach us from that satellite. To make the measurement we assume that both the satellite and our receiver are generating the same pseudo-random codes at exactly the same time. By comparing how late the satellite's pseudo-random code appears compared to our receiver's code, we determine how long it took to reach us. Multiply that travel time by the speed of light and you've got distance.

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GPS Signal GPS SIGNAL L1 1575.42 MHz C/A CodeP CodeNav. Data L2 1227.6 MHz C/A CodeNav. DataP Code

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Signals around 2015

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Satellite TX Model

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PRN - Calculating Position Speed of GPS signal = 3 x 10 8 ms -1 Distance from satellite = Speed x Time taken Distance = 3 x 10 8 ms -1 x t t must be found.

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GPS Signal Structure

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L1 Signal

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Pseudo Ranging Noise

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The distance (x) from one satellite tells us we're located somewhere on the surface of an imaginary sphere centered on that satellite with a radius of x. x miles

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Distance measurements from two satellites limits our location to the intersection of two spheres, which is a circle.

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A third measurement narrows our location to just two points.

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GPS Position Determination

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Good GDOP Poor GDOP

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Differential GPS An Introduction

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How does it work

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Hardware Configuration

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GPS RTK System GNSS Base station GNSS ROVER Station

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GPS Error Sources Ionospheric group delays Tropospheric refraction delays Ephemeris errors (e) Satellite clock errors (d) Receiver clock errors Multipath signal Satellite and receiver noises

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Application of GPS Technology Private and recreation Traveling by car Hiking, climbing, biking Vehicle control Mapping, survey, geology English Channel Tunnel Agriculture Aviation General and commercial Spacecraft Maritime

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45 of 10 Agriculture GPS Type Comparison PerformanceLowMiddleHighVery High TechnologyLow cost DGPS DGPSTwo Frequency DGPS Real Time Kinematic RTK GPS Price $100 to 600 $600 to $3,000 $1,500 to 10000 $25,000 to $42,000 Differential Source WAASWAAS + C.G. Beacon + SBAS WAAS + C. G. Beacon + HP SBAS User Base Station HP SBAS Static Accuracy 5-121-34-101 ApplicationScoutingMapping / Guidance Elevation mapping, Precision row operations

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GIS (Geographic Information System) A system for capturing, storing, checking, integrating, manipulating, analysing and displaying data which are spatially referenced to the Earth. This is normally considered to involve a spatially referenced computer database and appropriate applications software

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Globe Spherical Earths surface -radius 6371 km Meridians (lines of longitude) - passing through Greenwich, England as prime meridian or 0 longitude. Parallels (lines of latitude) - using equator as 0 latitude. degrees-minutes-seconds (DMS), decimal degrees (DD) True direction, shape, distance, and area

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Global Coordinate System

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Modeling The Earth Shape of the Earth (Equi-potential surface) Geoid Undulated shape Modeled as a spheroid World standard spheroid WGS84 Sri Lanka does not coincide with WGS84 Spheroid for Sri Lanka Everest 1830 WGS84Everest

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Shape of the Earth

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MAP Datum

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The X,Y,Z coordinate system.

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Seven-parameter methods

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Geoid, Spheroid & Surface ELLIPSOID GEOID

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Transverse-secant Cylindrical (Mercator) Projection CM: central meridian AB: standard meridian DE: standard meridian -105 -108 -102 Most New Mexico in Zone 13

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CylindricalTransverse CylindricalOblique CylindricalSecant Cylindrical ConicalSecant ConicalPlanarSecant Planar

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Sri Lankan Local Grid ( 0, 0 ) North Coordinate East Coordinate Piduruthalagala ( 200000, 200000 ) 0, 0

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Geographic Latitude/Longitude on a flat surface (WGS 84 datum) Scale, distance, area, and shape are all distorted with the distortion increasing toward the poles.

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GIS Software ArcGIS GRASS IDRISI ILWIS Quantum GIS MapInfo

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Using GIS - Sectors Archeology Aviation Agriculture Defence Telecommunication Survey & Mapping Disaster Management Health Irrigation Construction Navigation Urban Development Etc..

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Map Scale Scale refers to the relationship or ratio between a distance on a map and the distance on the earth it represents. Maps should display accurate distances and locations, and should be in a convenient and usable size. Map scales can be expressed as - representative fraction or ration: 1:100,000 or 1/100,000 - graphical scale: - verbal-style scale: 1 inch in map equal to 2000 feet on the ground or 1 inch = 2000 feet

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Agriculture with GNSS receivers

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Application of GPS Technology

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Our Product Training

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Thanks for your interest in the Global Positioning System Aruna Weerasinghe(Eng C&G) Retailit(pvt)ltd