OpenStreetMap
Much of the world does not follow the US model of freely providing government
created map data. Data may only be available at great cost, or in many
countries is not available for security reasons. The rise of cheap and
ubiquitous GPS in cell phones, and abundant satellite imagery, means that
individuals can create and share map data.
Openstreetmap.org serves this
function, and is an international effort. They have a web mapping site, and you can download their data.
Openstreet map coverage varies, depending on the whims of whomever did the
digitization.
- Street classification can abruptly change. Because the program
attempts to select the level of roads to show based on the map scale, at
some scales the roads can appear discontinuous because the classification
changes.
- The coverage of buildings also varies; at times one side of a street has
been digitized, and the opposite side has not.
In most cases your choices might well to be using Openstreetmap, or nothing,
but you must evaluate the map and decide which layers are usable for a
particular region.
The US State
Department has worked with OpenStreetMap for humanitarian relief efforts to
crowd source mapping after a disaster.
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OpenStreetMap is a free editable map of the
whole world. It is made by people like you.
It is crowd sourced, or open source, and is
similar to Wikipedia.
Open
Street Map has free streets, waterways, railroads, and other
layers in shapefile format (and other formats),
worldwide.
OSM download sites
Data
viewer (online)
- Download sites let you get much larger
areas in a directly usable format
- Export for a very small area from this map in OSM format, and then
convert to a shapefile
 Data Manipulation, Resample, OGR DXF/GPX/OSM to shapefile
Available coverage varies.
Baghdad, Iraq with color coding by the
attribute. This disiplay is not smart; all lines
are the same width, and colors are in
alphabetical order for the category names.
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OSM data in Normandy, displayed with rules in a database
(OSM_RULES.dbf, present in main MICRODEM directory).
This is a smart display, with the importance of
the roads indicated by:
- Line segment width.
- Color. Bright red is used for the
largest roads, and smaller roads get
increasingly less obvious colors.
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OpenStreetMap vector data sets have the following layers:
- Roads
- Points (features like schools, houses of worship, ATMs, metro stops)
- Places
- Waterways
- Railways
- Places (cities, towns, neighborhoods)
- Natural (things like forest, park, water, riverbank)
- Buildings
- Landuse (things like industrial, farm, residential)
What is included for a particular area varies, as does the completeness of
coverage within the area.
OpenStreetMap
Features (web wiki)
Using OpenStreetMap in MICRODEM
Last Revision 11/4/2019