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#Cartonama

#Introduction

  • format: lecture and discussion
  • slides: introduction and overview
  • software: need list of all software
  • data: none
  • other: none
  • time: 30 minutes
  • questions:
    • the goal ... alcohol shops map app? other ideas: bus stops
    • introduction to GIS and GeoData. familiar with GMapsAPI, but nothing more.
    • what are limits to google maps

#Approximately Four Half Days ##Creating Geo Data ##Working with Geo Data ##Visualizing Geo Data ##Building Apps with Geo Data

Goal: an location based app!

#Resources

Github repo of the slides and some materials

https://github.com/mikelmaron/Cartonama

The LiveBoot ISO

http://aeneous.coolwrks.com/sajjad/Cartonama-Workshop-Hasgeek.iso

Workshop Schedule

http://workshop.cartonama.org/

Mailing List

http://groups.google.com/group/cartonama-workshop

#CREATING GEO DATA

#Introduction to OpenStreetMap Came away with a solid base understanding of what OpenStreetMap is all about ... the motivations and the approach.

  • format: lecture
  • slides: basic OSM intro
  • software:
  • data:
  • other:
  • time: 30 minutes
  • questions:
    • license

#OpenStreetMap ##Collaborative Global Mapping, "like Wikipedia for Maps"

#what is OpenStreetMap? ##the openstreetmap "one-liner"

#Bangalore Animation http://www.youtube.com/watch?v=fpHKb-SZRh8

#Haiti

.notes: source http://news.bbc.co.uk/2/hi/uk_news/magazine/8517057.stm

#Before / After in OSM

#Destroyed buildings, IDP camps

#Uses ##Immediate recovery, ongoing reconstruction

#Map Kibera

.notes: sourc http://gallery.me.com/dbullington#100816&view=null&bgcolor=black&sel=12

#Kibera was a blank spot ##250,000 people, 2.5 km2

#The Mappers

#The Map!

#Voice of Kibera ##Hyper local, geotagged reporting, using Ushahidi http://voiceofkibera.org/

#What distinguishes OSM? ##Open License ##Technical Freedom ##Community

#Foursquare

http://blog.foursquare.com/2012/02/29/foursquare-is-joining-the-openstreetmap-movement-say-hi-to-pretty-new-maps/

#GPS Surveying for OSM Understand how to use a GPS and collect data for OSM

  • format: workshop
  • slides:
  • software:
  • data:
  • other: GPS units. Maybe Apps?
  • time: 1 hour
  • questions:
    • theory and practice
    • mobile: periodicity and accuracy. but what to use ... Android: MyTracks, others. OSMAnd --- unusable. what do they use in jbad?
    • POIs are not collected nearby to CIS ... street hawkers
    • MyTracks: can adjust frequency. gpx visible as mounted drives. uses GMaps as a basemap

#Einstein's Theory of Relativity and You!

Using the GPS

  • Turn on GPS
  • Get a Signal
  • Page to Map
  • Zoom and Pan
  • Record WayPoints by pushing joy stick straight in
  • Note Waypoint number

Record Data

  • Type of highway and names
  • Any interesting POI
  • Parking
  • Street Direction (one way street)‏
  • Land use
  • Walking paths, Cycleways, other routes
  • Specific Buildings and Amenities
  • Crossings, bridges, and tunnels
  • Additional Noteworthy Places and Landmarks
  • Tracks are recorded automatically
    • The track is a guideline, not the map!
  • Can use pen/paper, camera, dictaphone, mobile, etc
  • Work together to divide up the Cake!

#Let's Go

#Downloading from GPS Use of GPSBabel to download GPS data

  • format: workshop
  • slides: just show the commands
  • software: gpsbabel, drivers
  • data: results in GPX
  • other:
  • time: 20 minutes

Download data

  • Connect GPS with USB cable

    !sh sudo gpsbabel -i Garmin -f usb: -o gpx -F waypoints.gpx

Tracks

  • Change to USB Mode ... shows up as a drive
  • or add -t to gpsbabel command

Putting Maps on GPS

#Editing Data in OSM Facility with JOSM and Potlatch editors.

  • format: workshop
  • slides: maybe some JOSM screenshots
  • software: JOSM. Potlatch?
  • data: results in OSM
  • other:
  • time: 40 minutes
  • questions:

#JOSM

#Tagging, OSM data model and API Understand Tagging, Map Features, Editing Presets in JOSM and Potlatch

  • format: lecture
  • slides: needed
  • software:
  • data:
  • other:
  • time: 30 minutes
  • questions: how to generate interest

http://wiki.openstreetmap.org/wiki/Map_Features

#Local Names

highway = bus_stop
name = Domlur
name:en = Domlur
name:kn = ಡೊಮಲೂರು

http://www.openstreetmap.org/browse/changeset/10839653

#RESTful API

  • simple data format
  • tagging for metadata
  • standard map tiles
  • full planet dumps = thriving ecosystem of tools, renderers, editors, routers, applications

http://wiki.openstreetmap.org/wiki/APIs

  • Main editing API. GET/PUT/DELETE/POST
  • XAPI and Overpass GET
  • Planet and minutely diffs XML files

#Example request

GET http://api.openstreetmap.org/api/0.6/way/35

!xml

<osm version="0.6" generator="OpenStreetMap server">
<way id="35" visible="true" timestamp="2010-12-06T14:41:05Z" 
    version="5" changeset="6564105" user="blackadder" uid="735">
<nd ref="200542"/>
<nd ref="274057218"/>
<nd ref="1024965354"/>
<nd ref="200550"/>
<nd ref="1024940305"/>
<nd ref="1024940306"/>
<nd ref="1024940307"/>
<nd ref="200551"/>
<nd ref="200553"/>
<tag k="highway" v="footway"/>
<tag k="is_in" v="Sutton Coldfield"/>
<tag k="note" v="Fire Access Route"/>
<tag k="surface" v="paved"/>
</way>
</osm>

#Presets

!xml
<presets>
<group name="Health Service">

<item name="Basics">
<label text="Health Service" />

<text key="name" text="Service Name" />
<combo key="opening_hours" text="Opening Hours" values="24/7,Mo-Fr 08:30-20:00,Tu-Su 08:00-15:00; Sa 08:00-12:00" 
    default="" delete_if_empty="true" link="http://wiki.openstreetmap.org/wiki/Key:opening_hours" />

<label text=" " />
<text key="contact:phone" text="Mobile" 
    link="http://wiki.openstreetmap.org/wiki/Key:contact" />
<text key="contact:email" text="Email" 
    link="http:///wiki.openstreetmap.org/wiki/Key:contact" />
</group>
</presets>

http://josm.openstreetmap.de/wiki/TaggingPresets

http://wiki.openstreetmap.org/wiki/Develop

#Resources

#Results

OSM bus stop data for Bangalore

http://open.mapquestapi.com/xapi/api/0.6/node[highway=bus_stop][bbox=77.4256,12.8254,77.7844,13.1396]

https://github.com/mikelmaron/Cartonama/blob/master/data/busstops-bangalore.xml

#WORKING WITH GEO DATA

#or, "Points and Lines and Polygons, oh my!"

#A Round World

  • Not perfectly round
  • Not even regularly irregular
  • An "oblate spheroid"
  • spheroid versus geoid
  • geodesy

#Spheroids

  • semi-major axis (equatorial)
  • semi-minor axis (polar)
  • common spheroids
    • World Geodetic Survey 1984 (WGS84)
    • WGS 1972
    • Everest 1830 and 1956
    • NAD 1927 and 1983

#Coordinate Systems

  • Geographic: latitude and longitude in degrees
  • Projected: easting and northing in meters
  • False easting and northing
  • Datum: coordinate system origin
  • WHEN IN DOUBT, USE THE WGS84 SPHEROID AND DATUM

#Projections

  • Round(ish) world, flat map
  • Project on the surface of another solid in some orientation, then unwrap
  • Sacrifice shape, area, and/or direction
  • Allows us to use Cartesian coordinates (whew!)

Cylindrical projections

Transverse cylindrical projections

Conic projections

Plane projections

Azimuthal

Orthographic

#Projections worth knowing

  • Unprojected, or Equirectangular
  • Mercator
  • Universal Transverse Mercator (UTM)
  • Spherical or "Web" Mercator

#Equirectangular "Projection"

#Mercator

#Transverse Mercator

#Universal Transverse Mercator (UTM)

#Web Mercator

  • Originally implemented by Google
  • Now standard across web mapping services
  • By setting max lat to +/- 85.0511°, the world becomes square
  • This has implications for tiling

#Spatial Reference Systems

  • Projection + Spheroid + Datum + Units = SRS
  • Also known as "coordinate reference systems" (CRS)

#EPSG Codes

  • European Petroleum Standards Group
  • Established EPSG codes for common spatial reference systems
  • Unprojected Longitude/Latitude: EPSG 4326
  • Web Mercator: EPSG 3857
  • UTM zone 43 North: EPSG 32643 (for example)

#Geographic Data Models

Raster Data

Vector Data

"Raster is faster but vector is correcter."

#Raster Data

  • Grid: columns x rows
  • Cell values
    • Discrete
    • Continuous
    • Imagery
  • Georeferencing via affine transformation

#Affine Transformation

#Affine Transformations

#World File

32.0
0.0
0.0
-32.0
691200.0
4576000.0
  • A: x component of the pixel width (x-scale)
  • D: y component of the pixel width (y-skew)
  • B: x component of the pixel height (x-skew)
  • E: y component of the pixel height (negative y-scale)
  • C: x-coordinate of the center of the upper left pixel
  • F: y-coordinate of the center of the upper left pixel

(example borrowed from Wikipedia)

#Raster Formats

  • GeoTIFF (.tif)
    • World file (.wld, or .tfw)
    • Projection in "Well-Known Text" (.prj)
  • World files for JPEGs, or PNGs (.jpw, .pgw)
  • Others: BIL, JPEG2000, ECW, NITF, etc.

#Vector Data

  • The "Simple Features" Model
  • Feature
    • Attributes
    • Geometry

#Geometry Types

  • Point
  • Line
  • Polygon
  • Multi-geometries

#Points

  • x and y (and sometimes z)
  • don't forget, longitude is x and latitude is y
  • POINT(77.58 12.96)

#Lines

  • Just a sequence of Points
  • LINESTRING(77.56 12.95, 77.57 12.95, 77.58 12.96)

#Polygons

  • One or more closed rings
  • A ring is a linestring that intersects only at the first and last points
  • ∴ a square is represented with five points
  • POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))

#Donut Holes

  • Polygons have one exterior ring and zero or more interior rings
  • Interior rings are donut holes
  • POLYGON((0 0, 0 4, 4 4, 4 0, 0 0), (3 3, 3 1, 1 1, 1 3, 3 3))

#Winding Rule

  • Donut holes can have holes of their own
  • Rings that mark included areas are clockwise
  • Ring that mark donut holes are anti-clockwise
  • This is to make area calculations work right

#Vector Formats

  • ESRI Shapefile
  • GML
  • KML
  • GeoJSON
  • "Well-Known" Text (WKT) and Binary (WKB)
  • GeoRSS
  • GPX

#The misnamed "Shapefile"

  • .shp
  • .shx
  • .dbf
  • .prj
  • others (e.g. .sbn, .xml, etc.)

#GeoJSON

http://geojson.org/

{ "type": "Point", "coordinates": [77.58, 12.96] }

#GeoJSON LineString

{
    "type": "LineString",
    "coordinates": [ [100.0, 0.0], [101.0, 1.0] ]
}

#GeoJSON Polygon

{
    "type": "Polygon",
    "coordinates": [
        [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ]
    ]
}

#GeoJSON Donut Holes

{ 
    "type": "Polygon",
    "coordinates": [
        [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ],
        [ [100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2] ]
    ]
}

#GeoJSON Feature

{ 
    "type": "Feature",
    "geometry": {"type": "Point", "coordinates": [77.58, 12.96]},
    "properties": {"name": "Bangalore"}
}

N.B. Properties can be any legit JSON object!

#GeoJSON FeatureCollection

{
    "type": "FeatureCollection",
    "features": [ ... ]
}

#GEO ENABLED DATABASES

#PostGIS

  • A geospatial extension to PostgreSQL
  • Geometry operations
  • Spatial predicates
  • Spatial indexes
  • Spatial reference system support

#Create a PostGIS template database

##Create a PostGIS template

$ createdb template_gis
$ createlang plpgsql template_gis
$ psql template_gis </usr/share/postgis/postgis.sql
$ psql template_gis </usr/share/postgis/spatial_ref_sys.sql

##Make a spatial database from the template

$ createdb -Ttemplate_gis my_new_postgis_db

#PostGIS metadata tables

geometry_columns

      Column       |          Type          | Modifiers 
-------------------+------------------------+-----------
 f_table_catalog   | character varying(256) | not null
 f_table_schema    | character varying(256) | not null
 f_table_name      | character varying(256) | not null
 f_geometry_column | character varying(256) | not null
 coord_dimension   | integer                | not null
 srid              | integer                | not null
 type              | character varying(30)  | not null

spatial_ref_sys

  Column   |          Type           | Modifiers 
-----------+-------------------------+-----------
 srid      | integer                 | not null
 auth_name | character varying(256)  | 
 auth_srid | integer                 | 
 srtext    | character varying(2048) | 
 proj4text | character varying(2048) |

#Create a PostGIS table

Create the table

CREATE TABLE poi (id SERIAL, name VARCHAR);

Add the geometry column

SELECT AddGeometryColumn('poi','location',4326,'POINT',2);

#Create a PostGIS table

# \d poi
                   Table "public.poi"

  Column  |       Type        |         Modifiers
----------+-------------------+--------------------------------------
 id       | integer           | not null default nextval(...)
 name     | character varying | 
 location | geometry          | 

Check constraints:
    "enforce_dims_location" CHECK (st_ndims(location) = 2)
    "enforce_geotype_location" CHECK
        (geometrytype(location) = 'POINT'::text OR location IS NULL)
    "enforce_srid_location" CHECK (st_srid(location) = 4326)

#Create some spatial data

# INSERT INTO poi (name, location)
         VALUES ('CIS', 'POINT(77.6375384 12.9647134)');

ERROR:  new row for relation "poi" violates check constraint
        "enforce_srid_location"

# INSERT INTO poi (name, location)
         VALUES ('CIS', 'SRID=4326;POINT(77.6375384 12.9647134)');

INSERT 0 1

#Select some spatial data

# SELECT * FROM poi;

 id | name |                      location                      
----+------+----------------------------------------------------
  2 | CIS  | 0101000020E61000006D7CDC6DCD685340A4062EEAEEED2940
(1 row)

# SELECT id, name, AsText(location) FROM poi;

 id | name |            astext            
----+------+------------------------------
  2 | CIS  | POINT(77.6375384 12.9647134)
(1 row)

#Spatial predicates

  • Equals
  • Is Disjoint With
  • Intersects
  • Touches
  • Crosses
  • Is Within
  • Contains
  • Overlaps
  • Covers
  • Is Covered By

#DE-9IM "Dimensionally Extended 9 Intersection Model" (DE-9IM)

#PostGIS spatial predicates

  • ST_Equals(geom1, geom2)
  • ST_Disjoint(geom1, geom2)
  • ST_Intersects(geom1, geom2)
  • ST_Touches(geom1, geom2)
  • ST_Crosses(geom1, geom2)
  • ST_Within(geom1, geom2)
  • ST_Contains(geom1, geom2)
  • ST_Overlaps(geom1, geom2)
  • ST_Covers(geom1, geom2)
  • ST_CoveredBy(geom1, geom2)

#Load data from Shapefile

$ shp2pgsql -s4326 -I world_borders.shp admin0 | psql my_db

               Table "public.world_borders"
   Column   |         Type          |   Modifiers                          
------------+-----------------------+------------------------------
 gid        | integer               | not null default nextval(...)
 cat        | double precision      | 
 fips_cntry | character varying(80) | 
 cntry_name | character varying(80) | 
 area       | double precision      | 
 pop_cntry  | double precision      | 
 the_geom   | geometry              | 

Indexes:
    "world_borders_pkey" PRIMARY KEY, btree (gid)
    "world_borders_the_geom_gist" gist (the_geom)
Check constraints:
    "enforce_dims_the_geom" CHECK (st_ndims(the_geom) = 2)
    "enforce_geotype_the_geom" CHECK
        (geometrytype(the_geom) = 'MULTIPOLYGON'::text ...)
    "enforce_srid_the_geom" CHECK (st_srid(the_geom) = 4326)

#Apply a spatial predicate

# SELECT name, cntry_name FROM world_borders, poi
    WHERE st_contains(world_borders.the_geom, poi.location);

 name | cntry_name 
------+------------
 CIS  | India
(1 row)

#Geometry processing

  • ST_Union(geom1, geom2)
  • ST_Intersection(geom1, geom2)
  • ST_Difference(geom1, geom2)
  • ST_Buffer(geom, distance)
  • ST_ConvexHull(geom)
  • ST_Transform(geom, srid)
  • ... and many more!

#Geometry measurement

  • ST_Distance(geom1, geom2)
  • ST_Length(geom)
  • ST_Area(geom)
  • ST_Centroid(geom)
  • ST_Distance_Spheroid(geom1, geom2)
  • ... and many more!

#Area example

SELECT SUM(ST_Area(ST_Transform(the_geom, 32643))) / 1000000
    FROM world_borders WHERE cntry_name = 'India';

?column?     
------------------
3196343.52393187
(1 row)

#Spheroid distance example

SELECT ST_Distance_Sphere(
        'POINT(77.6375384 12.9647134)', 'POINT(122.7 37.4)') / 1000;

?column?     
------------------
5216.69910277434
(1 row)

#Spatial indexes?

# EXPLAIN SELECT name, cntry_name FROM world_borders, poi
          WHERE st_contains(world_borders.the_geom, poi.location);

                         QUERY PLAN
----------------------------------------------------------------------
 Nested Loop  (cost=0.00..1347.15 rows=1 width=14)
   Join Filter: ((world_borders.the_geom && poi.location) AND
                 _st_contains(world_borders.the_geom, poi.location))
   ->  Seq Scan on poi  (cost=0.00..1.01 rows=1 width=104)
   ->  Seq Scan on world_borders
                    (cost=0.00..352.84 rows=3784 width=6982)
(4 rows)

#Create a spatial index

# CREATE INDEX world_borders_the_geom_gist
         ON world_borders USING GIST (the_geom);

# EXPLAIN SELECT name, cntry_name FROM world_borders, poi
          WHERE st_contains(world_borders.the_geom, poi.location);

                         QUERY PLAN
----------------------------------------------------------------------
 Nested Loop  (cost=0.00..1815.00 rows=5 width=42)
   Join Filter: _st_contains(world_borders.the_geom, poi.location)
   ->  Seq Scan on poi  (cost=0.00..18.30 rows=830 width=64)
   ->  Index Scan using world_borders_the_geom_gist on world_borders
        (cost=0.00..1.90 rows=1 width=6982) 
         Index Cond: (the_geom && poi.location)
(6 rows)

#R-trees

#Dump a spatial table to a Shapefile

$ pgsql2shp my_db poi

Initializing... Done (postgis major version: 1).
Output shape: Point
Dumping: XX [1 rows].

#Data Swiss Army Knives

#GDAL/OGR

A F/OSS library that speaks dozens and dozens of formats

  • GDAL is for raster data
  • OGR is for vector data

#Exploring rasters

$ gdalinfo SRTM_fB03_n012e077.tif 

Driver: GTiff/GeoTIFF
Files: SRTM_fB03_n012e077.tif
Size is 1201, 1201
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (76.999583333333334,13.000416666666666)
Pixel Size = (0.000833333333333,-0.000833333333333)
Corner Coordinates:
Upper Left  (  76.9995833,  13.0004167) ( 76d59'58.50"E, 13d 0' 1.50"N)
Lower Left  (  76.9995833,  11.9995833) ( 76d59'58.50"E, 11d59'58.50"N)
Upper Right (  78.0004167,  13.0004167) ( 78d 0' 1.50"E, 13d 0' 1.50"N)
Lower Right (  78.0004167,  11.9995833) ( 78d 0' 1.50"E, 11d59'58.50"N)
Center      (  77.5000000,  12.5000000) ( 77d30' 0.00"E, 12d30' 0.00"N)
Band 1 Block=1201x1 Type=Float32, ColorInterp=Gray

#Transforming rasters

##gdal_translate

$ gdal_translate -of GTiff some_other_format.jpg a_better_format.tif

$ gdal_translate --formats

##gdalwarp

$ gdalwarp -t_srs EPSG:3875 some_file_in_4326.tif web_mercator.tif

##gdaladdo

$ gdaladdo satellite_image.tif 2 4 8 16 32

#Exploring vectors $ ogrinfo world_borders.shp

INFO: Open of `world_borders.shp'
      using driver `ESRI Shapefile' successful.
1: world_borders (Polygon)

#Exploring vectors $ ogrinfo world_borders.shp

Layer name: world_borders
Geometry: Polygon
Feature Count: 3784
Extent: (-180.000000, -90.000000) - (180.000000, 83.623596)
Layer SRS WKT:
(unknown)
CAT: Real (16.0)
FIPS_CNTRY: String (80.0)
CNTRY_NAME: String (80.0)
AREA: Real (15.2)
POP_CNTRY: Real (15.2)

OGRFeature(world_borders):0
  CAT (Real) =                1
  FIPS_CNTRY (String) = AA
  CNTRY_NAME (String) = Aruba
  AREA (Real) =          193.00
  POP_CNTRY (Real) =        71218.00
  POLYGON ((-69.882233 12.41111,-69.946945 12.436666, ...))

#Transforming vectors

Assigning SRS

$ ogr2ogr -a_srs epsg:4326 world_borders_4326.shp world_borders.shp

Transforming SRS

$ ogr2ogr -a_srs epsg:4326 -t_srs epsg:3875 world_borders_3875.shp world_borders.shp

Format conversion

$ ogr2ogr -f KML world_borders.kml world_borders.shp

Database support

$ ogr2ogr -f PostgreSQL PG:dbname=my_db world_borders.kml

#GeoCommons

#GeoCommons

#Quantum GIS (QGIS)

#Processing OSM Data

#OSM API

#OSM dumps

  • Formats

    • XML
    • Protocol Buffers (PBF)

  • Planet.osm

#OSM dumps

#osm2pgsql

Lat/Lon import

$ osm2pgsql -l -d my_db -s -G planet.osm.bz2

Mercator import

$ osm2pgsql -m -d my_db -s -G planet.osm.bz2

Partial import

$ osm2pgsql -l -d my_db -b -0.5,51.25,0.5,51.75 planet.extract.osm.bz2

Important flags

  • -l / -m = 4326 vs 3875
  • -s = "slim mode"
  • -G = compute multi-geometries
  • -b minlon,minlat,maxlon,maxlat = geographic extract

#osm2pgsql styles

  • "Style" dictates which tags get turned into columns

  • Default lives in /usr/share/osm2pgsql/default.style or similar

      # OsmType  Tag          DataType     Flags
  node,way   note         text         delete
  node,way   source       text         delete
  node,way   created_by   text         delete
  node,way   access       text         linear
  node,way   admin_level  text         linear
  node,way   aerialway    text         linear
  node,way   aeroway      text         polygon
  ...

#osm2pgsql schema

  • planet_osm_line: contains all imported ways
  • planet_osm_point: contains all imported nodes with tags
  • planet_osm_polygon: contains all imported polygons
  • planet_osm_roads: contains just the roads

#Osmosis

http://wiki.openstreetmap.org/wiki/Osmosis

Create a local API database

osmosis --read-xml file="planet.osm" --write-apidb database="x"

Apply a diff to an OSM file

osmosis --read-xml-change file="planetdiff-1-2.osc"
        --read-xml file="planet1.osm"
        --apply-change --write-xml file="planet2.osm"

Extract specific key value pairs

osmosis --read-xml city.osm 
        --way-key-value keyValueList="railway.tram,railway.tram_stop"
        --used-node --write-xml city_tram.osm

Extract a bounding box

bzcat downloaded.osm.bz2 | osmosis\
    --read-xml enableDateParsing=no file=-\
    --bounding-box top=49.5138 left=10.9351 bottom=49.3866 right=11.201
    --write-xml file=-\
   | bzip2 > extracted.osm.bz2

#osmium

http://wiki.openstreetmap.org/wiki/Osmium

/*
  run with: osmjs -l sparsetable -j extract-nodes.js OSMFILE
*/

wanted_keys = [ ... ];

Osmium.Callbacks.node = function() {
  if(!this.tags["name"] && !this.tags["place_name"]) return;
  found_wanted_keys = false;
  for (var i = 0; i < wanted_keys.length; i++) {
    if (this.tags[wanted_keys[i]]) {
        found_wanted_keys = true;
        break;
    }
  }
  if (!found_wanted_keys) return;
  print(JSON.stringify({
    "geom": [this.geom.lon, this.geom.lat],
    "tags": this.tags, 
    "type":"node", 
    "id": this.id
    })
  )
}

#Shapefile export via osmjs

var shp_pois = Osmium.Output.Shapefile.open('./pois', 'point');
shp_pois.add_field('id', 'integer', 10);
shp_pois.add_field('type', 'string', 32);
shp_pois.add_field('name', 'string', 32);

var node_tags = {
    amenity: { restaurant: 'restaurant', pub: 'pub' },
    shop: { supermarket: 'supermarket' }
}

(continued...)

#Shapefile export via osmjs, part 2

Osmium.Callbacks.node = function() {
    for (var key in this.tags) {
        if (node_tags[key]) {
            var type = node_tags[key][this.tags[key]];
            if (type) {
                shp_pois.add(this.geom, {
                    id: this.id,
                    type: type, 
                    name: this.tags.name
                });
            }
        }
    }
}

Osmium.Callbacks.end = function() {
    shp_pois.close();
}

#Results

https://github.com/mikelmaron/Cartonama/blob/master/data/bangalore-bus-shp.zip

#VISUALIZING GEO DATA

#Tiles

http://tile.server/layer/${Z}/${X}/${Y}.png

  • Zoom 0 = 40 = 1
  • Zoom 1 = 41 = 4
  • Zoom 2 = 42 = 16
  • ...
  • Zoom 18 = 418 = 68 719 476 736

#TileMill Creating Tiles w/ TileMill

  • format: tutorial
  • slides: adding data, carto, mapbox
  • software: tilemill
  • data: Shapefiles and/or PostGIS. result in tiles.
  • other:
  • time: 1.5 hours

#Multi-lingual Tiles

  • format: tutorial?
  • slides:
  • software:
  • data: need to make sure data collected and processed into shapefile includes translations
  • other:
  • time: 30 minutes
  • questions: really try to show this, though it might be tricky

#Carto references localized name

@futura_med: "Kedage Normal", "Futura Medium","Function Pro Medium","Ubuntu Regular","Trebuchet MS Regular","DejaVu Sans Book","unifont Medium";

#bus_stops {
  marker-width: 2;
  marker-line-color: #00f;
  text-fill: #b50d38;
  text-name: "[name_kn]";
  text-face-name: @futura_med;
  text-size: 12;
  text-dx: 5;
  text-allow-overlap: false;  
}

https://tiles.mapbox.com/groundtruth/map/map-busd5lm5

#Serving Tiles Ways to serve tiles ... TileCache (for imagery), TileStache, MapBox, mod_tile, etc

  • format: lecture
  • slides: show the various ways and how to configure
  • software:
  • data:
  • other:
  • time: 30 minutes
  • questions: hands on or?

#TileStache

tilestache.cfg

{
  "cache": {
    "name": "Disk",
    "path": "/tmp/stache",
  },
  "layers": {
    "blr": {
      "provider": { "name": "mapnik", "mapfile": "style.xml" }
    }
  }
}

Starting it

python tilestache-server.py -c tilestache.cfg

#TileCache

tilecache.cfg

[cache]
type=Disk
base=/tmp/tilecache

[blr]
type=MapnikLayer
mapfile=style.xml
extension=png
srs=EPSG:3857
tms_type=google

Starting it

python tilecache_http_server.py

#Results

https://tiles.mapbox.com/groundtruth/map/map-busd5lm5

#BUILDING APPS WITH GEO DATA

#Javascript Mapping APIs survey Javascript Mapping APIs (OpenLayers, ModestMaps, GMaps API, Leaflet, Mapstraction)

  • more interest in this
  • format: lecture
  • slides:
  • software:
  • data:
  • other:
  • time: 30 minutes
  • questions: survey the options, and pick one

leaflet and discussion

#What is a Javascript Mapping API do?

  • "Slippy Map"
  • Display different layers (tiles, markers, vectors, WMS, images, KML, GeoJSON)
  • Interactive Controls (Zoom/Pan, Layer Switcher, Popups, Drawing Tools)
  • Mobile and Web

Basically, GIS viewer, made appropriate for the web

OpenLayers

  • Comprehensive and Extensible
    • Data Formats
    • Drawing Tools
    • Projections
    • Different Tiling schemes
    • Clustering
    • Embed other APIs
  • Large JS, you should customize your build
  • Has an entire book http://openlayers.org/

Leaflet

"Leaflet doesn't try to do everything for everyone. Instead it focuses on making the basic things work perfectly."

  • Most of what you might need (unless you need more)

http://leaflet.cloudmade.com/

#GMaps API

  • Geocoding, Directions, StreetView

#Others

  • Mapstraction
  • Bing
  • ModestMaps
  • MapQuest
  • Nokia
  • dozens more

#Make some GeoJSON

ogr2ogr -f "GeoJSON" bangalore-stops.json bus_stops.shp

#Leaflet Starting Example

leaflet_start.html

#Leaflet GeoJSON Example

leaflet_geojson.html

#Geocoding and Location Queries

  • format: workshop
  • slides: basic geocoding apis. and a basic location query proxy?
  • software:
  • data:
  • other:
  • time: 45 minutes
  • questions: more interest in this. is there a small postgis->geojson web service? maybe flask, or node.js. python would have postgis bindings

show nominatim, geonames, overpass api

#Nominatim

http://nominatim.openstreetmap.org/search?q=bangalore&format=json&polygon=1

http://wiki.openstreetmap.org/wiki/Nominatim

#Reverse Geocoding

http://nominatim.openstreetmap.org/reverse?format=xml&lat=12.964761&lon=77.637527&addressdetails=1

#Location Queries

XAPI

#Routing

  • Good data for Routing (graphs, weights: restrictions, speed, cycling, etc)
  • Algorithms
  • Directions APIs
  • Routing Engines
  • OpenTripPlanner

#Putting it all Together Create an app using, tiles and search, generated from the collected data.

  • format: workshop
  • slides: instructions
  • software: html, css, js.
  • data: tiles, database. this results in the app.
  • other:
  • time: 1.5 hours
  • questions: would be nice to have this app built.

#POSM

https://github.com/yuvipanda/POSM http://yuvi.in/POSM/

#Proxy

lrwxrwxrwx 1 root root 28 2012-03-03 11:45 proxy.load -> ../mods-available/proxy.load
lrwxrwxrwx 1 root root 28 2012-03-03 11:45 proxy.conf -> ../mods-available/proxy.conf
lrwxrwxrwx 1 root root 33 2012-03-03 11:53 proxy_http.load -> ../mods-available/proxy_http.load

proxy.conf

ProxyPass /osm http://api.openstreetmap.org
ProxyPass /overpass http://overpass.osm.rambler.ru/cgi/interpreter
ProxyPassReverse /osm http://api.openstreetmap.org
ProxyPassReverse /overpass http://overpass.osm.rambler.ru/cgi/interpreter

#Change tiles

diff --git a/assets/www/js/main.js b/assets/www/js/main.js
index cdaf34a..63279c1 100644
--- a/assets/www/js/main.js
+++ b/assets/www/js/main.js
@@ -135,8 +135,7 @@ function resizeContentArea() {
 function init() {
     $(window).bind('orientationchange pageshow resize', resizeContentArea);
     map = new L.Map('map');
-
-    var tiles = new L.TileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
+    var tiles = new L.TileLayer('http://{s}.tiles.mapbox.com/v3/mapbox.mapbox-streets,groundtruth.bangalore-bus-stops-kannada/{z}/{x}/{y}.png', {
         //attribution: 'Map data &copy; 2011 OpenStreetMap contributors'
         attribution: 'Tiles Courtesy of <a href="http://www.mapquest.com/" target="_blank">MapQuest</a> <img src="http://developer.mapquest.com/content/osm/
     });
@@ -290,6 +289,7 @@ $(function() {
     }, 300);
 });

#Customize layers to edit assets/www/zoomData.js

#How about Authentication
assets/www/main.js

#How is a Changeset created assets/www/changesets.js

#How is a node updated assets/www/poi.js

#How are nodes loaded assets/www/poimanager.js

#Cartonama

#SUGGESTIONS

#Managing Map Data in MySQL or Postgres

  • there is a session on this in "Working"

#Routing fundamentals

  • could simply be a lecture during part 4.

#How to pick a mapping service

  • part of Javascript Mapping APIs, or earlier during OSM?

#Building mobile location based apps

#Maps and Frameworks?

  • Django, Drupal, Rails