Post on 08-Feb-2017
GEOMEETUP – OVERVIEW OF GEOSPATIAL TECHNOLOGIES Ragi Burhum
Schizophrenic} http://xkcd.com/713/
1) The “basics” of Geo
2) Answer the #1 question asked in the survey for this GeoMeetup (from all 7 answers)
3) Geo-Demos
The structure of chaos
Does this number mean anything to you?
404
How about this one?
4326
Let’s get the basics out of the way.
Objects in the real world are represented by:
1) A collection of “standard” attributes. For example: age (int), length(double), color (enum), name (string), etc.
2) 1 or many “spatial” attributes. For example: location (point geometry), shape (polygon geometry), route traveled (line geometry), etc
The formal name for those objects in GIS is features.
Summary of Geo-concepts
Image: http://johanneskebeck.spaces.live.com
Open Geospatial Consortium (OGC)
Simple Features for SQL (SFSQL)
The feature’s geometry can be represented in different coordinate systems – commonly referred to as Spatial Reference.
Summary of Geo-concepts
img: [1]
In case you were wondering, 4326 is the spatial reference identifier (SRID) assigned to the WGS84 spatial reference system published by the European Petroleum Survey Group (EPSG).
Projected Coordinate Systems
Summary of Geo-concepts
•Many geospatial formats out there•They all use various indexing mechanism•Many libraries, APIs, services, applications, etc. to leverage the concept of a geometry (e.g. http://postgis.refractions.net/docs/reference.html)
“What parcels are within 1km of this fire?”
SELECT owner_phoneFROM parcelsWHERE ST_DWithin( geom, ‘POINT()’, 1000 );
“How far did the bus travel last week?”
SELECT Sum(ST_Length(geom))FROM vehicle_pathsWHERE (v_id = 12) AND (v_date > Now() - ‘7d’);
1) The “basics” of Geo
2) Answer the #1 question asked in the survey for this GeoMeetup (from all 7 answers)
3) Geo-Demos
The structure of chaos
#1 Q: What is available as Open Source?
WEB MAPPING SOFTWARE
projects
projects
MapBuilder MapGuideOpen Source
WEB MAPPING SOFTWARE
DESKTOP APPLICATIONS
projects
DESKTOP APPLICATIONS
projects
GRASS GIS
OSSIM
GEOSPATIAL LIBRARIES
projects
projectsGEOSPATIAL LIBRARIES
FDO
That is a tiny little fraction of what is available out there. Many companiesin the Web 2.0 space (pardon me for lackof a better word that word) open source their geospatial technology and data.
“I am tired of listening to you talk.SHOW ME SOMETHING”
1) The “basics” of Geo
2) Answer the #1 question asked in the survey for this GeoMeetup (from all 7 answers)
3) Geo-Demos
The structure of chaos
1) Showing *a lot* of data on a webmap – Google style.
2) OpenStreetMap
3) A tiny ESRI product sample
4) Creating your own tiles and leveraging a spatial db
5) Beyond Streetview – Merging augmented reality and enterprise GeoData.
6) Machine Learning and automatic feature detection.
Pick your GeoDemo poison
References
• One GeoDemo based on Paul Ramsey’s (OpenGeo) Where 2.0 workshop:
http://workshops.opengeo.org/postgis-spatialdbtips/
Some slides shamelessly copied from his slides.