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/