Internet enabled GIS

GIS Topics and ApplicationsJohn Reiser

Rowan University

GIS as a Support System

• GIS has become a critical component in:– Land & Real Estate Management– Transportation & Traffic Engineering– Environmental Studies– Urban Planning– Civil Engineering– Facilities & Building Management– Fleet Control & Routing– Mobile & Location-Based Services

Yesterday's GIS

• GIS used to be tied to the back office.• Trade or purchase GIS data.• Data stored on the same computer as the

software.• GIS was anchored to one place and only a select

few had access.• Computing is now distributed across a network

that is accessible nearly everywhere.

Before, data was stored on disk, on site.Before, data was stored on disk, on site.

Before, data was stored on disk, on site.Now, the data is available across the 'Net.Before, data was stored on disk, on site.

Now, the data is available across the 'Net.

Internet GIS

• Internet-enabled GIS allows professionals and the public a level of access to information that was previously impossible.

• Professionals can report on and update maps and data in the field.

• The public can now access plans with ease; even contribute to the planning process via the web.

Internet GIS

• Making GIS accessible• Accessing data using the web

– Web Map Services (ArcIMS, WMS & WFS)– GIS servers & Location-based Services– Keyhole Markup Language (KML)

• Distributing data using the web– Basic and advanced distribution– Basics of generating and distributing KML– Overview of instituting a WMS

Data Accessibility

• We can easily share data now– FTP– ZIP files posted to the web

• Helps GIS users, but outsiders are left in the dark• Inviting, easy to use map interfaces are the new

way to share

Making GIS AccessibleMaking GIS Accessible

Making GIS AccessibleMaking GIS Accessible

Click icon to add picture

Making GIS AccessibleMaking GIS Accessible

NYCityMap gis.nyc.gov/doitt/nycitymap/

NYCityMap gis.nyc.gov/doitt/nycitymap/

Basics of Internet-enabled GIS

• Simple, open formats, usually XML based• Data can be emailed or hosted on a webserver• Uses a public or private GIS server for additional

features– KML is overlaid on top of images provided by Google

• Data is either geospatially aware map images, or actual GIS data in a web friendly format.

Images versus Data

• Map services usually deliver images of maps that include information allowing software to properly position the image on the Earth.

• Some map services deliver map images, along with attribute information about the features in the map image.

• Other map services deliver just GIS data, leaving it up to the client application to render the data on the screen.

Spectrum of Services

Images OnlyData Only

Images OnlyData Only

TileServices

Web Map

Service

Web Feature Service

ArcIMS ArcGIS KML

ArcGIS Server & ArcIMS

• ESRI's server-side software• Allows ArcGIS desktop & mobile users access to a

central GIS database• Generates map images and exports feature info• Many counties and large cities use this software• Serves ArcGIS and web browser users• Can also provide WMS and WFS services• Incredibly feature rich, but expensive

Web Map Service

• WMS is a protocol for requesting rendered map tiles from a GIS server

• Data returned is a map image• Allows access to the attribute information via

XML• REST-ful protocol – necessary info within the URL• Open standard, free to implement

Web Feature Service

• WFS allows for retrieval of GIS features and properties from a remote server

• Data is GIS features; data, not maps• WFS also allows updating GIS data on a remote

server• Returns XML data

KML

• Once a "closed" language, Google pushed for its adoption as an open standard

• KML is a subset of XML and related to GML• KML stores vector data along with symbology • KML can act as a wrapper for WMS services

Finding GIS Resources

• The Federal Government and each State maintains a Spatial Data Clearinghouse.

• Ours (in my opinion) is one of the best• NJ Geographic Information Network

http://njgin.state.nj.us/• Federal Geo Onestop

http://geodata.gov

Geospatial One-Stopgeodata.gov

Geospatial One-Stopgeodata.gov

NJ Geographic Information Networknjgin.state.nj.us

NJ Geographic Information Networknjgin.state.nj.us

NJGIN's Explorer

• Use Explorer to search metadata records

• Search by theme, keyword and area

• Downloads as well as live web services are indexed

• Provides links to connect to servers

Information Warehousenjgin.state.nj.us

Information Warehousenjgin.state.nj.us

County IMS Sites

• Several NJ counties have public ArcIMS websites that offer several county datasets

• None so far offer WMS services, so ArcGIS dependent

Cape May County's IMScapemaycountyims.netCape May County's IMScapemaycountyims.net

ArcGIS and IMS Sites

• IMS sites can be configured to allow access using ArcGIS

• Most of the NJ County IMS sites are configured allowing access

ArcIMS FeaturesImages and Features

ArcIMS FeaturesImages and Features

Image Image

FeaturesFeatures

Accessed via a web browser…Accessed via a web browser…

and ArcGIS.and ArcGIS.

Image Service allows for basic selections using the interactive selection tools.

Image Service allows for basic selections using the interactive selection tools.

Feature Service allows for selection using the Select by Location tool.

Feature Service allows for selection using the Select by Location tool.

200' from this property

200' from this property

Selected features can then be exported to a shapefile or local geodatabase.

Selected features can then be exported to a shapefile or local geodatabase.

First Part of Lab

Workshop

Using KML to Enhance Your Data

What exactly is KML?

• Keyhole Markup Language allows for an open exchange of GIS data, as well as:– symbology for every data element– 3D models (COLLADA) that have been georeferenced– camera viewpoints and tours– network links and web services

• XML based, human readable, text format• OGC standard – open and license free

Why KML?

• There are free shapefile viewers for Windows – why don't we just use them?

• Shapefiles are just GIS data.• KML allows you to define colors and icons for

your GIS data, as well as set view points and include notes and links to other pages and data.

• KML gives your users access to your data, prepared the way you want.

KML Basics – mygeoposition.com

KML Basics – mygeoposition.com

KML Structure

• Unlike shapefiles, KML is not just data.

• Container format for vector data, raster data, network links and dynamic data.

• Data is organized into folders that can be rearranged and nested.

KML File

KML File

Group Laye

r

Group Laye

r

GIS La

yer

GIS La

yer

PolygonsPolygons

Image OverlayImage Overlay

KML and Network Links

• KML is a relatively new format and was designed with the Internet in mind.

• KML supports network links, allowing remote KML data to be accessed on the fly.

• KML also supports WMS layers, acting as a wrapper for the image service.

• Lightweight files can be distributed to your users• Network links guarantee that users will always

have the latest data.

KML Viewers

• The default data format for Google Earth is KML.• Google Maps has some basic KML viewing

capability – paste a URL into the map search.• ESRI's free ArcExplorer can also view KML.• Those without GIS can easily download any of

these free applications to view your map data.

Google Earth

• In the workshop, you will export your data into KML format and view it in Google Earth.

• Google Earth provides the richest user experience of all the KML viewers.

• Google Earth also provides the largest library of GIS data.

• It doesn't mean that it's the only option – many of the other viewers have a purpose, too!

KML in Google EarthKML in Google Earth

Google Maps

• Google Maps supports points, lines, polygons, overlays and network links in KML files.

• You can host KML, provide the link to Google Maps, and share your data in the same way.

• Limited by browser's capabilities – most computers can only handle 100 features before a performance hit.

• Simplest way to share data to users without any need to install additional software.

KML in Google MapsKML in Google Maps

KML without ArcGIS

• If you have some GIS data – – shapefiles– tabular (CSV with coordinates)– or just KML you'd like hosted

there are several websites that will convert and host your data as an interactive map and KML.

• One of these sites is GeoCommons.• Another site useful for quick KML point

generation is MyGeoPosition.

GeoCommons – geocommons.comGeoCommons – geocommons.com

GeoCommons Finder!GeoCommons Finder!

GeoCommons Maker!GeoCommons Maker!

Going Further

• KML is a great resource for distributing GIS data, but it has its limitations

• GIS specialists and developers that specialize in KML can help you push those limits.

• When your organization is ready to move up to a GIS server, you should know that there are several options available to you.

• Commercial and Open Source options.

Second Part of Lab

Workshop