Mapping the Wireless Revolution or, Over the Hills

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Mapping the Wireless Revolutionor, Over the
Hills Through the Woods
with Rich Gibson Schuyler ErleNoCat
NetworkSebastpol, California
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What are we looking at?
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What are we looking at?
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What are we looking at?
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What are we looking at?
What are we looking at?

• Maps tell stories.
• The Big Bend maps tell different stories about
  the same place.
• In an increasingly digital and increasingly
  mobile age, where attention is at a premium, we
  need maps that tell the right stories.
• (Have you ever tried to read a GPS while
  driving?)

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What's the story?
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A brief digression...
Albert Einstein, when asked to describe radio,
replied "You see, wire telegraph is a kind of a
very, very long cat. You pull his tail in New
York and his head is meowing in Los Angeles. Do
you understand this? And radio operates exactly
the same way you send signals here, they receive
them there. The only difference is that there is
no cat."
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You Say You Want a Revolution?

• The NoCat Network is a free community network
  built with fixed-point 802.11b links.
• Microwave radio requires line-of-sight over long
  distances.
• Who can see whom?
• Suppose we have 100 participants.

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You Say You Want a Revolution?

• The NoCat Network is a free community network
  built with fixed-point 802.11b links.
• Microwave radio requires line-of-sight over long
  distances.
• Who can see whom?
• Suppose we have 100 participants.

100 99 2 4,950 possible links!
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You Say You Want a Revolution?
100 99 2 4,950 possible links!
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Communities gather around stories.
We need maps that tell ours.
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What's the story?

• Too much context the enemy of attention
  conservation!

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What's the story?

• Right sort of story but not enough context.

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Maps tell stories!

• We want systems for the management, acquisition,
  and presentation of geospatial information.
• This means
• Acquiring geospatial information
• Exploring that information playing what if?
• Creating a narrative

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We need our own maps!

• And, in the spirit of community, we want to allow
  others to replicate our efforts.
• That means
• Open Source software
• Freely available data sources
• Fortunately, there's a ton of both!

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The 45 second introduction toGeographic
Information Systems

• Layers
• Data sources
• Coordinate systems
• Projections
• Mad props to cartographers of yore

(It's not only not regular, it's not even
regularly irregular.)
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Layers
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Streams and Rivers
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Roads
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NoCat Folk
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All Together Now
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Open Data Sources

• TIGER
• a/k/a Topologically Integrated Geographic
  Encoding and Referencing system
• Collected by U.S. Census Bureau
• Contains lines and polygons of most relevant
  features
• Inaccurate and wildly incomplete, but, hey it's
  free!

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Open Data Sources

• GNIS
• USGS's official repository of domestic geographic
  names information
• Contains almost 2 million physical and cultural
  geographic features
• Just lat, long, and elevation...

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Open Data Sources

• Other USGS sources
• Digital Line Graph (DLG)
• Digital Raster Graph (DRG)
• Orthophoto Quads
• Bay Area Regional Database (BARD)
• ... but, wait, there's more!

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Open Data Sources

• Digital Elevation Models (DEM)
• Available from USGS
• Elevation at 10 or 30 meter resolution for the
  entire U.S.
• Can be converted to contour vectors
• Hey, we can calculate LoS with that!

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Make your own!

• GPS
• Netstumbler / Kismet
• Journals, diaries, travelogues, etc.
• RDF ... ?

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TIGER Mapsurfer

• http//tiger.census.gov/cgi-bin/mapsurfer
• What's cool Instant, attractive maps.
• What sucks These maps don't tell our story the
  server is slow when under load also
• "We cannot provide the TMS source code. The TIGER
  Map Service (TMS) was started in 1995 as a "proof
  of concept" of a basic Web mapping application,
  and was not done with a view to providing the
  public with Internet mapping software.... This
  test application was not completely documented as
  the Census Bureau never intended to disseminate
  it to the public. As written, the software is
  hardware specific and some components of the
  uncompiled source code used to generate the
  mapping engine have been lost."
• But in a pinch it works!

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GRASS

• Geographic Resource Analysis Support System
• Collection of UNIX programs with a Tcl/Tk
  front-end.
• Open Source!
• Does everything!
• Hard to use!

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GRASS
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FreeGIS

• The FreeGIS Project provides
• Software overview on free Geographic Information
  Systems
• Communication on developments, plans, info on
  free GIS software and free geo-data
• Software and data prepared for direct use
• http//www.freegis.org

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OpenGIS

• Industry consortium devoted to open standards and
  freely available data.
• Publishes open specifications
• Simple Features Specification for SQL
• Geography Markup Language (GML)
• Web Feature Services (WFS)
• Web Mapping Services (WMS)
• http//www.opengis.org

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PostGIS

• Adds support for geographic objects to the
  PostgreSQL object-relational database.
• Very useful as a backend spatial database for GIS
  applications, like Oracle's Spatial extension.
• Follows the OpenGIS Simple Features Spec.
• Many free tools (e.g. GDAL, Mapserver) can talk
  directly to PostGIS.
• http//postgis.refractions.net

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MapServer

• Open Source web-based GIS browser.
• Capable of reading data from a variety of
  sources, including GRASS and PostGIS.
• Mapscript bindings for Perl, Python, Tcl, Guile,
  and Java!

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wifimaps.com
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wifimaps.com
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Personal Telco Project

• Node maps via MapServer
• Nodebot - an IRC resource
• Reports nearest PTP node locations via IRC.
• !locatenodes 2109.NW.Irving.St.Portland.
  OR.97210 3 miles
• closest node is 0.164997 miles
  Decentric (node id 264)
• Uses an XML-RPC interface to PHP MapScript!
• GeoWiki
• Python MapScript plug-in for MoinMoin
• http//personaltelco.net/index.cgi?MoinMap

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NoCat Maps

• What it does
• Node database
• Geocoding
• Elevation profiles
• http//maps.nocat.net
• Goal
• All you need is a compass and an antenna!

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Node Database
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Geocoding

• Adding geospatial information to other data
• NoCat uses TIGER data, with lat/long for each
  end of a street segment, plus address ranges for
  each side of the street.

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Link Summary
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No Line of Sight...
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Could it be?
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NoCat Maps

• What it doesn't account for
• Curvature of the Earth
• Fresnel zones
• Ground clutter

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Where We're At

• A frustrating, complex, confusing, weakly
  documented array of nitty-gritty technical
  details.
• Building useful map databases is still a black
  art.

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The Bright Future

• Visualization tools that allow us to play what
  if easily the spreadsheet analogy
• Web services that expose public databases and
  facilitate the development of map-based
  applications

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Vivá la revolucion!
http//maps.nocat.net