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GOOGLE EARTH“For anyone who has ever dreamed of flying….” – NY Times

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GOOGLE EARTH - INTRODUCTION

• The most popular virtual globe.• Developed by Keyhole, Inc. named as Earth

Viewer• Bought by Google and renamed as Google

Earth in 2005

• uses broadband streaming technology and 3-D graphics to enable users to interactively explore the entire world

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GOOGLE EARTH - FEATURES

• 3D buildings in major cities across the World  • 3D terrain showing mountains, valleys, and canyons

around the world  • Integrated Google Local search to find local information

such as hotels, restaurants, schools, parks, and transportation 

• Fast, dynamic navigation  • Video playback of driving directions  • Tilt, rotate, and activate 3D terrain and buildings for a

different perspective on a location  • Easy creation and sharing of annotations among users

using KML (Keyhole Mapping Language)

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3D buildings

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Public Transit

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3D terrain

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GOOGLE EARTH - Specifications

• Baseline resolutions

– U.S.: 15 m – Global: Generally 15 m (some areas such as certain oceanic

islands are in extremely low resolution)• Typical high resolutions

– U.S.: 1 m, 0.6 m, 0.3 m, 0.15 m (extremely rare; e.g. Cambridge, Ma.)

• Altitude resolution: – Surface: – Seabed: Not applicable (the seabed is "printed" on the spherical

surface). • Age: Usually less than 3 years old.

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Getting things done

with

Google Earth….

The Technical Aspect

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Getting things done with Google Earth

• Three-dimensional geospatial data are managed in Google Earth using KML (Keyhole Markup Language)

• KML files are often distributed as KMZ, zipped KML files

• The KML file specifies a feature (a place mark, image, or polygon) for Google Earth

• It contains a basic description of the place, longitude, latitude, tilt and other information

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Getting things done with Google EarthA

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<?xml version="1.0" encoding="UTF-8"?><kml xmlns="http://earth.google.com/kml/2.0"><Placemark> <name>The Pentagon</name> <LookAt> <longitude>-77.05580139178142</longitude> <latitude>38.870832443487</latitude> <range>742.0552506670548</range> <tilt>48.09646074797388</tilt> <heading>59.88865561738225</heading> </LookAt> <Polygon> <extrude>1</extrude> <altitudeMode>relativeToGround</altitudeMode> <outerBoundaryIs> <LinearRing> <coordinates> -77.05788457660967,38.87253259892824,100 -77.05465973756702,38.87291016281703,100 -77.05315536854791,38.87053267794386,100 -77.05552622493516,38.868757801256,100 -77.05844056290393,38.86996206506943,100 -77.05788457660967,38.87253259892824,100 </coordinates> </LinearRing> </outerBoundaryIs> <innerBoundaryIs> <LinearRing> <coordinates> -77.05668055019126,38.87154239798456,100 -77.05542625960818,38.87167890344077,100 -77.05485125901024,38.87076535397792,100 -77.05577677433152,38.87008686581446,100 -77.05691162017543,38.87054446963351,100 -77.05668055019126,38.87154239798456,100 </coordinates> </LinearRing> </innerBoundaryIs> </Polygon></Placemark></kml>

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Result after opening the .kml file containing the code

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AJAX TECHNOLOGY

• It’s an approach

“a way of thinking about the architecture of web applications

using certain technologies”.

• Ajax isn’t something you can download.“Asynchronous JavaScript +CSS + DOM +XMLHttpRequest”

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Ajax incorporates:• Standards-based presentation using XHTML and CSS (Cascading Style

Sheets (CSS) is a simple mechanism for adding style (e.g. fonts, colors, spacing) to Web documents)

• Dynamic display and interaction using the DOM Document Object Model (The XML Document Object Model (XML DOM) defines a standard way for accessing and manipulating XML documents)

• Data interchange and manipulation using XML and XSL TransformationsXSL (Extensible Style Sheet language) which is a language for transforming XML documents into other XML documents

• Asynchronous data retrieval using XMLHttpRequest; XMLHttpRequest is the technical component that makes the asynchronous server communication possible;

• And JavaScript binding everything together.

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HOW IS AJAX DIFFERENT???

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Example of AJAX

NY seeGoogle Maps with NYC Live Traffic Cams, Yahoo Traffic News and A9 Blockview Photos. AJAX gone wild, gotta love it. The traffic cams are not video, a more accurate description would be live streaming images (some refresh faster than others).

http://www.alkemis.com/default.asp?pID=laboratory

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Will Google Earth replace Arc GIS?

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Will Google Earth replace Arc GIS?

• The answer is certainly not.

• They cannot be compared in this sense.

• Google Earth focuses on presenting data rather than analyzing and processing.

• The best approach will be to analyze data in Arc GIS and present them using Google Earth.

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Will Google Earth replace Arc GIS?Analysis of data

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Presentation of data

Will Google Earth replace Arc GIS?

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Will Google Earth replace Arc GIS?Analysis of data

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Presentation of data

Will Google Earth replace Arc GIS?

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OTHER MAJOR PLAYERS

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MS Virtual Earth

• Combines real-world imaging with the usefulness of a traditional road map by letting people see aerial photos with an overlay of road networks and point-of-interest information

• Uses Wi-Fi access points or Internet Protocol address geocoding to determine a person’s location

• Provides users with a simple way to compile search results that can be e-mailed, copied into a document or even added to a weblog on MSN Spaces

• Can be bookmarked, e-mailed to a friend or copied into a clipboard using Permalink

• Users can query information in broad, flexible ways using “Yellow Page Directories” feature.

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NASA World Wind• World Wind allows any user to zoom from satellite altitude into any

place on Earth • It has a full copy of the Blue Marble, a spectacular true-color image

of the entire Earth as seen on NASA's Earth Observatory: the Blue Marble

• Can display a dramatic view of the Earth at eye level. • Can take animations and play them directly on the world • Is capable of browsing through and displaying GLOBE data based

on any time the user wants• Has a complete set of borders that traces every country and state • Has a full catalog of countries, capitals, counties, cities, towns, and

even historical references• Has a variety of visual guides that help the user's experience such

as latitude and longitude lines, as well as extremely precise coordinate data

• Has the capability to display actual 3d models of landmarks on the earth

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Comparison  Google Earth Virtual Earth World Wind

Images Color Black and white Color

Coverage World USA World

Application download Yes No Yes

Streets Graphical Overlay Label overlay N/A

Search for schools, parks, restaurants, and hotels (Local search)

Yes Yes No

Get driving directions Yes Yes  No

Tilt and rotate the view in 3D Yes No Yes

3D Terrain Yes No Yes

Drawing tools Yes No No

GPS device data import  Yes No No

Data import Yes  No No

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Comparison

• Google Earth, Virtual Earth and World Wind are not entirely comparable, due to significantly different focuses and development history/philosophies

• Though Google Earth is not a totally free and open source software (as is NASA World Wind), it is easier to use and also offers wide varieties of features.

• Unlike any virtual globe, Google Earth provides data manipulation features and it allows users to access its API’s

• Google Earth is popular among the masses so data presentation can be done easily and effectively.

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Conclusion

• ~12 Million Google Earth downloads.

• 164,467 total registered users

• 102 registered online

• 1683 unregistered online

The above figure (unofficial) shows the popularity of Google Earth. In general Google Earth is involving people into the field of

GIS.

At present Google Earth is used extensively by media for news

coverage and other things.

It is gaining equal importance among other fields aswell.

Arc GIS users and other GIS professionals can use Google Earth for

more better and effective performance.

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Is GOOGLE EARTH the new face of a future

GIS???

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THANK YOU