Introduction to
Global Positioning Systems (GPS)
Module 1
Created by: Scott Kelly 2010
1. Satellites2. Receiver/Unit3. Ground Control4. Computers5. Human Element
A Global Positioning System (GPS) includes:
Original image source: ESA
Very high orbit– 12,550 miles (20,200 km)– 1 revolution in about 12 hrs– Travel approx. 7,000mph
Considerations– Accuracy – Geometry– Coverage
The OmnipresentGPS Receiver
Image Source: Cabalas
Image Source: Trillium Wood Golf Club
Image Source: GPSinformati on.org
Satell ites Map Waypoints/Tracks
MenuNavigati on
Image Source: USGS
Image Source: Schriever Air Force Base
Image source: Golf-Monthly
Image Source: fanpop.com
Purpose Tool Direction Interaction User
The Human Element
How Global Positioning Systems
Work
1. Datum & Projections2. Data Collection3. Unit to Computer
11
Geodetic Datum: What are they?
Define the size and shape of the earth
Used as basis for coordinate systems
Variety of models:- Flat earth- Spherical- Ellipsoidal
WGS 84 defines geoid heights for the entire earth
Based on Geodetic Datum
Describe locations in two or three dimensions (ie. X,Y,Z or X,Y)
Local and Global
Common systemsGeodetic Lat, Long (global)UTM (local)State Plane (local)
Variety of transformation methods
Coordinate Systems
Triangulation
Satellite A Satellite B
Satellite C Satellite D
Image Source: topofusion.com/jamboree
Image Source: http://www.4x4books.com/mttngps.htm
Unit to Computer
Original Image Source: Wired.com
Image Source: http://www.leica-geosystems.com/en/News-Archive_57049.htm?id=1319
GPS/GISApplying the field
Image Source: http://202.28.94.55/web/322103/2551/work1/g178/home.html and others
Image Source: blog.doc.govt.nz/2009/08/