MapTube and Streaming Google Earth Sharing Data via Anonymous Servers

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MapTube and Streaming Google Earth Sharing Data
via Anonymous Servers
UCL CENTRE FOR ADVANCED SPATIAL ANALYSIS
Google Earth and Google Maps have changed the
nature of sharing Geographical Information to
such an extent that the ability to view data from
a global to street level is now often taken for
granted. Sharing data in Google Maps is not
however an easy task it still requires
significant skills in GIS. MapTube developed as
part of the GeoVUE project aims to address this
with a simple click through interface allowing
users to share any data. In a similar way to
YouTube the data is held on an external server
opening up the possibility of a central map
resource and data sharing. We preview MapTube in
this seminar as well as detailing the latest work
on Virtual London and Google Earth.

• Richard Milton and Andrew Hudson-Smith
• CASA UCL

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New Google Earth Features

• Network links and LODs
• eSociety ..\data\DUG-examples\eSociety\mapstest.km
  z
• 13.7MB 10921 files
• Virtual London ..\data\DUG-examples\Westminster.km
  l
• 3.3GB 2337 files
• Animation Bars
• Geocoding

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The Maptube Idea

• Publishing geospatial datasets on the internet
  requires a map to put the data on.
• Using Google Maps data can be hosted legally.
• Building custom tile layers for Google Maps that
  render data on the fly requires code that
  executes on the server and can be very slow.
• Most users do not have access to a programmable
  server e.g. ISPs and Google Pages.
• So why not pre-render all the tiles remove the
  programmable server component speed up the map
  rendering and give everybody the ability to host
  geospatial data on their own website
• Because there are a lot of tiles (274877906944
  at zoom level 19)
• but data tends to fall into one of two
  categories small scale or large scale for
  example GPS tracked pollution levels at a 5
  metre resolution or crime data for London
  councils.
• So why not create an application that can
  automatically create a Google Maps website from a
  shapefile and that allows the user to control the
  number of tiles by limiting either the zoom level
  or the geographical area

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GMapCreator

• GMapCreator demonstration of OAC website
  creation
• OAC-London ..\data\DUG-examples\OAC\oac-super.htm
  l
• 179MB (439MB) 98018 files
• OAC-East Midlands ..\data\DUG-examples\OAC\oac-su
  per-EM.html
• 7.61MB (16MB) 2689 files
• Some buildings ..\data\MapTube\LC_TQ1268_height_d
  ata_product_v1.html

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MapTube - Sharing Data

• Allow users to upload their shapefiles and let us
  host their data but users can still use the tool
  to create and host their own data the best of
  both worlds
• By holding the data on our server in a raw
  format we have the potential for combining
  datasets. This might raise some legal issues.
• If the service becomes popular we are going to
  need a bigger server.

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Hardware
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Rich Web Pages

• Javascript Java and HTML styling MapTube with
  components
• Google Web Toolkit
• Point-based data and clustering ononesite and
  eSociety
• GPS Tracking and GPX
• Linking 2D and 3D
• Fade data in and out

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Point Data

• The clustering algorithm must be representative
• The pin limit causes problems when panning
• Live Demo http//localhost8080/googlemaps/esocie
  ty2.html

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Weather Data Synoptic Data

• Weather data is shown drawn around a station
  circle
• Wind direction is indicated by the arrow and
  speed by the number of fleches
• Symbols on the left show weather conditions e.g.
  rain
• Pressure temperature and dewpoint are also
  displayed

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Fading Data

• Problem the data completely obscures the map or
  is hard to understand if transparent
• Fade the data or the map
• Alpha channel in png

Live demo ..\..\share\opacitytestcensus\erg_OA_20
01_ks01ks02ks15_percentage_WGS84.html
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Linking Google Maps and Google Earth

• Google Earth is an ActiveX object
• A web page can open Google Earth and control it
  through a COM interface in javascript
• Follow a GPS track around Virtual London

Live Demo ..\..\share\Tracking3D\GPXViewer3D.html
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Pollution Tracking
A cyclist with a GPS and carbon monoxide sensor
was tracked cycling around Bristol. The data is
published on the web as an animated track using
Google Maps. Live demo http//www.casa.ucl.ac.uk/
bbc/dontdieyoung/log_25-09-2006_154206.html
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Conclusion