Desktop, Mobile & Web Based Desktop, Mobile & Web Based GIS/ Collaborative GISGIS/ Collaborative GIS

Lecture 4Lecture 4

Desktop GISDesktop GIS Create, edit, and analyze Create, edit, and analyze geographic data on your desktop geographic data on your desktop computer. computer.

See your data on a map. See your data on a map. Analyze your data to reveal Analyze your data to reveal patterns, relationships, and trends patterns, relationships, and trends that are not readily apparent in that are not readily apparent in tabular format. tabular format.

Create publication quality, Create publication quality, professional maps. professional maps.

ArcGIS Desktop is software that allows you to discover patterns, relationships, and trends in your data that are not readily apparent in databases, spreadsheets, or statistical packages.

ArcGIS DesktopArcGIS Desktop

Desktop GISDesktop GIS

AdvantagesAdvantages• You have all the You have all the data and data and processing at processing at your stationyour station

DisadvantagesDisadvantages• You must invest You must invest in the processor in the processor and storage spaceand storage space

• Data and maps are Data and maps are not easily sharednot easily shared

Mobil GISMobil GISMobile GIS is the Mobile GIS is the expansion of a expansion of a geographic geographic information system information system (GIS) from the (GIS) from the office into the office into the field. field.

A mobile GIS enables A mobile GIS enables field based field based personnel to personnel to capture, store, capture, store, update, manipulate, update, manipulate, analyze, and analyze, and display geographic display geographic information. information.

Mobile GIS integrates one or more Mobile GIS integrates one or more of the following technologies:of the following technologies:

Mobile devices Mobile devices • ArcGIS MobileArcGIS Mobile• ArcPad ArcPad • StreetMap StreetMap Mobile Software Developer KitMobile Software Developer Kit

Global Positioning Systems (GPS) Global Positioning Systems (GPS) Wireless communications for Wireless communications for Internet GIS access Internet GIS access

Mobile GISMobile GIS

AdvantageAdvantage• PortablePortable• Allows for some Allows for some map processingmap processing

DisadvantagesDisadvantages• Minimal storage Minimal storage spacespace

• Need a desktop Need a desktop for most for most processingprocessing

Web Based GISWeb Based GIS

Access 2D maps, 3D globes, reference Access 2D maps, 3D globes, reference layers, and functional tasks via the layers, and functional tasks via the Web to support your GIS work. Web to support your GIS work.

Contribute your own data for Contribute your own data for publishing through ArcGIS Online and publishing through ArcGIS Online and make it broadly available to other make it broadly available to other users. users.

Purchase the data you see in ArcGIS Purchase the data you see in ArcGIS Online and publish it on your own Online and publish it on your own server.server.

Web Based GISWeb Based GIS

AdvantagesAdvantages• Minimal processor Minimal processor and storage space and storage space neededneeded

• Many data sets Many data sets availableavailable

• The processor on The processor on the web server is the web server is likely to be more likely to be more powerful than powerful than your desktop unityour desktop unit

DisadvantagesDisadvantages• Must have a fast Must have a fast network network connectionconnection

• Data resides off Data resides off sitesite

• Dependent on Dependent on resources off resources off site, not under site, not under your controlyour control

Collaborative GISCollaborative GIS

Web Based GIS where multiple Web Based GIS where multiple users can add data to a single users can add data to a single map.map.

Collaborative GISCollaborative GIS

AdvantagesAdvantages• Allows for input Allows for input from:from:

Multiple UsersMultiple Users Multiple Data Multiple Data SetsSets

Multiple Multiple PerspectivesPerspectives

DisadvantagesDisadvantages• Lack of control Lack of control over input to the over input to the map and revisionsmap and revisions

Raster vs. VectorRaster vs. Vector

Lecture 5Lecture 5

Raster and Vector Reality  Raster and Vector Reality 

One of the sharpest One of the sharpest distinctions among GIS is the distinctions among GIS is the way that location is way that location is represented in a database, as represented in a database, as either a raster or vector either a raster or vector position.  position.  

These materials were developed by Kenneth E. Foote and Donald J. Huebner, Department of Geography, University of Texas at Austin, 1996.

Raster vs. VectorRaster vs. Vector

"Raster is vaster, Vector is more "Raster is vaster, Vector is more correcter"correcter"

The Raster View of the World The Raster View of the World A raster based system displays, locates, and A raster based system displays, locates, and stores graphical data by using a matrix or stores graphical data by using a matrix or grid of cells.grid of cells.

Each cell has an (x,y) location and a (z) Each cell has an (x,y) location and a (z) value which stores attribute data about that value which stores attribute data about that location.location.

The Vector View of the World The Vector View of the World A vector based system displays graphical data as A vector based system displays graphical data as points, lines or curves, or areas with points, lines or curves, or areas with attributes.attributes.

Advantages and DisadvantagesAdvantages and DisadvantagesMethod Method Advantages Advantages DisadvantagesDisadvantages

RasterRaster

Simple data structure Simple data structure Compatible with Compatible with remotely sensed or remotely sensed or scanned data scanned data Simple spatial Simple spatial analysis procedures analysis procedures

Requires greater storage space on Requires greater storage space on computer computer Depending on pixel size, graphical Depending on pixel size, graphical output may be less pleasing output may be less pleasing Projection transformations are more Projection transformations are more difficult difficult More difficult to represent More difficult to represent

topological relationships topological relationships  VectorVector Requires less disk Requires less disk

storage space storage space Topological Topological relationships are relationships are readily maintained readily maintained Graphical output more Graphical output more closely resembles hand-closely resembles hand-drawn maps drawn maps

More complex data structure More complex data structure Not as compatible with remotely Not as compatible with remotely sensed data sensed data Software and hardware are often more Software and hardware are often more expensive expensive Some spatial analysis procedures may Some spatial analysis procedures may be more difficult be more difficult Overlaying multiple vector maps is Overlaying multiple vector maps is often time consuming  often time consuming 

These materials were developed by Kenneth E. Foote and Donald J. Huebner, Department of Geography, University of Texas at Austin, 1996.

Raster Raster data can be converted to data can be converted to VectorVector and vice versa and vice versa

Note: Converting from one system to the other can introduce error.

These materials were developed by Kenneth E. Foote and Donald J. Huebner, Department of Geography, University of Texas at Austin, 1996.