gps training
TRANSCRIPT
GPS one day training
A quick and dirty introduction to GIS and spatial data collection
Dr. Catherine Pfeifer
Objective of the day
You will know
● How a GPS works
● About diversity of GIS software to map your own data
● The advantages and disadvantages of different GIS software
You will be able
● to set a GPS right
● To collect data point and track your path with a GPS (to calculate area)
● To map your own data in a GIS software
● To choose the GIS software that suits your situation and needs
Program of the day
● Playing a game to know each other ● Theoretical introduction to GIS● Setting a GPS right● How to collect points, lines (tracks), areas● Downloading your data● GIS software (Arc, QGIS, google earth)● Map your data in your favorite GIS software● Discuss your work and the difference between the
softwares
Program of the day
● Playing a game to know each other ● Theoretical introduction to GIS● Setting a GPS right● How to collect points, lines (tracks), areas● Downloading your data● GIS software (Arc, QGIS, google earth)● Map your data in your favorite GIS software● Discuss your work and the difference between the
softwares
Program of the day
● Playing a game to know each other ● Theoretical introduction to GIS● Setting a GPS right● How to collect points, lines (tracks), areas● Downloading your data● GIS software (Arc, QGIS, google earth)● Map your data in your favorite GIS software● Discuss your work and the difference between the
softwares
A theoretical introduction to GIS
● What is GIS and spatial data?● What is a coordinate system and why is it
important?● How to collect data? How does a GPS work?● How to represent spatial data? An overview of GIS
softwares
What is GIS ?
Spatial data as representation of the real world
● Spatial layer represents one information that can be overlaid for analysis
● Two types of data – Vectors (points,
lines, polygons)
– Grids
A theoretical introduction to GIS
● What is GIS and spatial data?● What is a coordinate system and why is it
important?● How to collect data? How does a GPS work?● How to represent spatial data? An overview of GIS
softwares
Coordinate systems
What is a coordinate system?
A coordinate system is a reference system used to represent the locations of geographic features, imagery, and observations such as GPS locations within a common geographic framework.
Coordinate system types : • Geographic coordinate system
(global/spherical) • Projected system (“making the world flat”)
Map projection
UTM projection
‘pseudocylindrical’ conformal projection (it preserves shape)
Concepts linked to coordinate system
● Datum : assumed shape of the earth ● Projection : none = geographic coordinate system
otherwise method applied for “flattening the world” (example Mercator UTM)
● Coordinate format – Degree minutes seconds, degree minutes, decimal
degrees (geographic coordinates)
– Meters, kilometers (projected coordinates)
Internationally used settings
Each country has national standards, but the international standard is often default in many software.
● Datum :WGS 84
● Projection
– None for geographic
– UTM (use sheet 37 N for Ethiopia)
– (the national projection for Ethiopia is Adindan but we recommend to use international standards)
● Coordinate format
– Decimal degrees (geographic)
– Meter (projected)
What to keep in mind
● GPS work generally with unprojected data● If you are not sure what you are doing use
international standards● Always write down what settings you used● Ask a GIS specialist before doing “strange things”
like re-project or assign projection
A SMALL MISTAKE MAY LEAD TO DAYS OF WORK FOR A GIS SPECIALIST AND IN THE WORST CASE YOUR DATA IS USELESS
A theoretical introduction to GIS
● What is GIS and spatial data?● What is a coordinate system and why is it
important?● How to collect data? How does a GPS work?● How to represent spatial data? An overview of GIS
softwares
Geographical Positioning System
● Uses satellites to locate the receiver
● With smartphone hybrid systems (mobile and wiki network)
What data can you collect with a GPS?
● Points (farmer's homestead)● Tracks (lines, path traveled)● Areas (farmer's field) works only on expensive
Garmin GPS
Settings in your GPS
● Must match with the settings you are going to use in the GIS software
● Advice use WGS84 unprojected, coordinate in decimal degrees
– All google geo-application use these settings
– It is also default in QGIS
Downloading your GPS data
● With a GPS software (DNR Garmin/mytracks)● With a plug-in module in an existing GIS software
(google earth/QGIS)● Manually (in an excel sheet, then read into a GIS
software)
A theoretical introduction to GIS
● What is GIS and spatial data?● What is a coordinate system and why is it
important?● How to collect data? How does a GPS work?● How to represent spatial data? An overview of
GIS softwares
GIS software
● Full GIS solution– ArcGIS (can be enhanced with DNR garmin)
– QGIS (with GPS plug-in)
– Google earth (with GPS feature on windows)
● GPS data download software– DNR garmin (can be linked with GPS)
– Many others
● Others– Drivers for gps
– Android tracking program (mytracks)
Program of the day
● Playing a game to know each other ● Theoretical introduction to GIS● Setting a GPS right● How to collect points, lines (tracks), areas● Downloading your data● GIS software (Arc, QGIS, google earth)● Map your data in your favorite GIS software● Discuss your work and the difference between the
softwares